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Stress relaxation is a time-dependent mechanical behavior of textile materials, which can affect the performance of the fabrics in various applications, especially technical applications such as tensile structures, geotextiles, and medical textiles. The present study aims to consider the effect of fabric structure (Tricot, Locknit, Satin, Queen’s cord, Reverse Locknit, and Sharkskin) on the tensile stress relaxation of biaxial warp-knitted fabrics. According to the results, the fabric structure remarkably influences its stress relaxation. The stress relaxation of the fabric in the course direction increases by increasing the length of underlaps in the front and back guide bars. Using elastic yarns as weft yarns in the fabric structure reduces the stress relaxation of the fabric in the course direction without affecting the fabric’s stress relaxation in the wale direction. Finally, to improve the functionality of pressure garments under stress relaxation, using elastic weft yarns in the fabric structure and bounding the warp and weft yarns in the biaxial warp-knitted fabrics by the Tricot structure is proposed. [ABSTRACT FROM AUTHOR]

Welded hollow spherical joints (WHSJs) are commonly used joints in grid structures, and their mechanical behavior under fire will directly affect the service life and safety behavior of grid structures. Therefore, the WHSJs were heated to the specified high temperature, and the tensile experiments were performed on non-stiffened WHSJs exposed to elevated temperatures. The failure modes, axial load–displacement curves, and mechanical behavior of the non-stiffened WHSJs exposed to elevated temperature were obtained. The experiment indicates that the failure mode of the axial tensile non-stiffened WHSJs is a pull-out failure. With the increase of heating temperature, the mechanical behavior of non-stiffened WHSJs gradually declines. The ductility of the non-stiffened WHSJs gradually increases with the heating temperature. Compared with the existing studies, the load-bearing capacity reduction trend of WHSJ exposed to elevated temperature is basically similar, and the stiffener has basically no function to improve the behavior of tensile WHSJs exposed to elevated temperature. The reliability of the numerical simulation was proved by comparison with experiments. According to the finite element analysis, the design method for the mechanical behavior of the non-stiffened WHSJs subjected to axial tension exposed to elevated temperature was proposed. [ABSTRACT FROM AUTHOR]

Stainless steels have many practical applications requiring various mechanical or chemical demands in the working environment. By optimizing a device used in mechanical experiments for torsional loading, several cylindrical samples were tested (both ends twisted with the same torque value in opposite directions) of 316L stainless steel (SS) to evaluate changes in the structural, chemical, and mechanical characteristics. Initially, the experimental samples were pre-loaded by tension in the elastic range (6%) and then subjected to torsion (772°) at different rates: 5, 10, and 20 mm/min. The experimental sequence consisted of a combined loading protocol with an initial tensile test followed by a subsequent torsional test. Two reference tests were performed by fracturing the samples in both torsion and tension to determine the mechanical strength parameters. The macro- and microstructural evolution of the samples as a function of the torsional degree was followed by scanning electron microscopy. The microhardness modification of the material was observed because of the strain (the microhardness variation from the center of the disk sample to the edge was also monitored). Structurally, all samples showed grain size changes because of torsional/compressive deformation zones and an increase in the degree of grain boundary misorientation. From the tensile and torsional behaviors of 316L SS and the structural results obtained, it was concluded that these materials are suitable for complex stress states in the elasto-plastic range through tensile and torsion. A reduction in Young's modulus of up to four times the initial value at medium and high stress rates was observed when complex stresses were applied. [ABSTRACT FROM AUTHOR]

It has proven to be a difficult task to design and provide an ankle-foot orthosis (AFO) that enables the client to walk securely and comfortably without bearing weight through the lower leg and foot skeletal parts. Although it is widely acknowledged that the patella tendon weightbearing (PTB) ankle-loot orthosis only partially unweights the lower tibia, ankle, and foot, it is nevertheless frequently prescribed for this purpose. In this work, two ankle foot orthoses of the AFO PTB type of Calf-corset were manufactured using a vacuum molding technique based on two kinds of materials as composite material reinforcement. The first AFO material was based on 8 layers of Perlon, while the second was based on 8 layers of fiberglass. A tensile and a fatigue test had been used to investigate the mechanical properties of the AFOs' material. The findings revealed that the yield strength (Ϭy) is 42.897 MPa, the tensile strength (Ϭult) for Perlon is 42.993 MPa, and the elongation at break is 1.138 mm, whereas fiber glass has a tensile strength (Ϭult), yield strength (Ϭy), and elongation at break of 224 MPa, 170 MPa, and 2.17 mm, respectively. Additionally, the gait cycle and the collected data on distributed pressure are measured using force plates and F-socket devices. The patellar tendon-bearing model was constructed using the SolidWorks software tool. In addition, for the fiber glass and Perlon PTB orthosis models, the total deformation, safety factor of fatigue, and Von-Mises stress were calculated using the FEM (ANSYS). The safety factor of fatigue values for the material PTBO with 8 layers of fiber glass was 2.2895, and for 8 layers of Perlon, it was 0.083515. [ABSTRACT FROM AUTHOR]

This study compares dip brazing and TIG welding operations carried out under optimal conditions on the parameters of strength, deformation, and ability to resist shocks for Al-64430 joints, which find extensive use in automobile and telecommunication industries. The fabricated samples were tested for bump test, surface deformation, microhardness and tensile strength, and the joint properties were studied through SEM, EDAX mapping and EDX. Compared to the dip-brazed samples, the TIG welded samples achieved 161% greater strength and 1000% greater elongation but subsequently 1330% higher surface deformation. Both joints were able to pass the bump test; however, some degree of cracks were observed post testing in both samples. Both samples achieved similar joint microhardness values, but notably, compared with the TIG welded sample, the brazed sample showed no HAZ zones in terms of microhardness variation, where a substantial decrease in microhardness was recorded. This absence of the HAZ region was also confirmed through the microstructure. Both primary and secondary silicon were observed in brazed samples, which had finer grain sizes than did the welded samples. Dendrite formation was observed for the brazed samples, whereas a uniform distribution of aluminium was observed for the welded samples. Fractographic analysis revealed brittle intergranular fracture with small dimples present at the fracture point for the brazed joints, while out-of-plane fracture with sharp edges indicated a more ductile nature for welded joints. [ABSTRACT FROM AUTHOR]

Braided composites are gaining attention in the most industrial applications. To design rods with optimal tensile properties against combined loads, experimental studies were conducted to investigate the effect of using axial yarn and core in different categories on the tensile properties of braided reinforced composite rods. In this study, six types of braided composite rods with different arrangements of braid components (axial yarn or core type) were produced using glass and polyester fibers with epoxy resin as the matrix. The elastic modulus, ultimate tensile strength, and work of fracture of these rods were tested, and the experimental elastic modulus of samples were compared with previously developed models. Moreover, comparing the stress-strain results of the samples revealed that the produced hybrid samples demonstrate pseudo-ductile tensile behavior, showing varying trends as the type of reinforcement is altered. The results indicate that using a double-layer triaxial braid as reinforcement for the composite can increase the elastic modulus up to 13% compared to the similar single-layer sample. Additionally, employing a double-layer triaxial braid as reinforcement for the composite leads to a greater work of fracture. However, in terms of ultimate tensile strength, biaxial braid reinforcement demonstrates better performance in reinforcing the composite rods. [ABSTRACT FROM AUTHOR]

In the present study, the influence of nickel (Ni) and silicon (Si) additions to the Ti-15 V-3Al-3Cr-3Sn (Ti-15-3) fillers on microstructure and mechanical properties of Ti-15-3 gas tungsten arc (GTA) weldments was investigated. Controlled amounts of Ni and Si as grain refiners were introduced into the molten pool of Ti-15-3 alloy by pre-placing the cast inserts (Ti-15-3-x wt.% Ni (x = 0.15, 0.30, 0.5) and Ti-15-3-xwt.% Si (x = 0.15, 0.30, 0.50)) by GTA welding (GTAW). Microstructural examination of welds with Ni and Si additions revealed refined grains in the fusion zone (FZ) characterized by nonlinear grain boundaries. The grain refinement that is mainly caused by Ni and Si additions develops constitutional supercooling (CS) ahead of the solid–liquid (S/L) interface in the FZ. It has been shown that welds prepared with Ti-15-3-0.5 Ni filler (yield strength (YS) of 688 ± 6 MPa, ultimate tensile strength (UTS) of 721 ± 5 MPa, and % elongation (%El) of 9 ± 0.5%) and Ti-15-3-0.5 Si filler (YS = 693 ± 6 MPa, UTS = 725 ± 5 MPa, %El = 8 ± 0.5%) exhibited higher strength compared to autogenous weld (YS = 575 ± 4 MPa, UTS = 597 ± 4 MPa, %El = 11 ± 0.5%). The increased strength observed in welds made using Ti-15-3-0.5Ni filler and Ti-15-3-0.5Si filler can be attributed to the narrower width of columnar β grains and the presence of equiaxed grains in the FZ. Post-weld heat treatment (PWHT) for all the weldments resulted in improved tensile strength and hardness of the weldments, which was attributed to the fine and uniform precipitation of the α phase in FZ. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to evaluate the development of composites made of epoxy (E) resin with different weight percentages of polypropylene (PP) and graphene oxide (Go) to form nanocomposite plates. Design/methodology/approach: A hand lay-up process was used to develop 21 different composites, with varying concentrations of PP (5%–35%) and Go (5%–35%). A ternary composite of E matrix was produced by combining binary fillers PP and Go (5%–35%) in a 1:1 ratio to a (95%–5%) solution. With the help of adopting the melt condensation deal to extract Go, the modified Hummers method was used to make Go platelets. Findings: Through field emission scanning electron microscopy (FESEM) and X-ray diffraction investigations, the particulate's size and structural characteristics were identified. Based on the FESEM analysis of the collapsed zones of the composites, a warp-and-weft-like structure is evident, which endorses the growth yield strength, flexural modulus and impact strength of the composites. Originality/value: The developed nanocomposites have exceptional mechanical capabilities compared to plain E resin, with E resin exhibiting better tensile strength, modulus and flexural strength when combined with 10% PP and 10% Go. When compared to neat E resin, materials formed from composites have exceptional mechanical properties. When mixed with 10% PP and 10% Go, E resin in particular displays improved tensile strength (23 MPa), tensile modulus (4.15 GPa), flexural strength (75.6 MPa) and other attributes. Engineering implications include automobile side door panels, spacecraft applications, brake pads and flexible battery guards. [ABSTRACT FROM AUTHOR]

This paper presents the results of research on the technical–economic optimization of FDM parameters (Lh—layer height and Id—infill density percentage) for the manufacture of tensile and compression samples from recycled materials (r) of PETG (polyethylene terephthalate glycol) and ASA (acrylonitrile styrene acrylate) in the context of the transition to a circular economy. To carry out our technical–economic study, the fundamental principle of value analysis was used, which consists of maximizing the ratio between Vi and Cp, where Vi represents the mechanical characteristic (tensile strength or compressive strength) and Cp represents the production cost. The results of this study showed that, in the case of tensile samples manufactured by recycled PETG (rPETG), the parameter that significantly influences the results of the Vi/Cp ratios is Lh (the height of the layer), while for the samples manufactured additively from recycled ASA (rASA), the parameter that decisively influences the tensile strength is Id (the infill density percentage). In the case of compression samples manufactured by FDM from recycled PETG (rPETG) and recycled ASA (rASA), the parameter that signified influences the results of the Vi/Cp ratios is Id (the infill density percentage). Following the optimization of the FDM parameters, using multiple-response optimization, we identified the optimal parameters for the manufacture of parts by FDM from rPETG and rASA: Lh = 0.20 mm and Id = 100%. The results of this study demonstrated that the use of recycled plastics from PETG and ASA lends itself to a production and consumption model based on a circular economy. [ABSTRACT FROM AUTHOR]

The study focus on fiber‐reinforced polymer composite materials, which are widely used in the mechanical industries for various applications. While using the composite materials, mechanical properties such as tensile, flexural, and interlaminar shear strength plays vital role in selection of composite materials. The current work aims to investigate the influence of adding nanosilica at varying weight percentages (0, 2, and 4) to the epoxy matrix on the tensile, flexural, and interlaminar shear strengths of the fiber‐reinforced polymer hybrid nanocomposite. The five carbon and four Kevlar layer hybrid polymer nanocomposites are made with woven fibers. The method used to improve the dispersion of nanosilica in the epoxy resin was high‐speed shearing. The hand lay‐up process was used to manufacture hybrid polymer nanocomposite laminates, which were then effectively postcured. The tests for tensile strength, flexural strength, and interlaminar shear strength were carried out in accordance with ASTM standards D3039, D790, and D2344, respectively. According to the tested specimens, a hybrid composite including 2 wt.% of nanosilica with epoxy provides better tensile strength of 6.83%, flexural strength of 10.13%, and interlaminar shear strength of 13.54% more than a hybrid composite without nanosilica. At 4 wt.% of nanosilica addition to epoxy matrix, the tensile, flexural, and interlaminar shear strength decreased when compared to 2 wt.% of nanosilica due to agglomeration. The addition of 2 wt.% nanosilica to the epoxy matrix in carbon/Kevlar fiber‐reinforced polymer hybrid composites yields superior tensile, flexural, and interlaminar shear strength compared to other weight percentages. [ABSTRACT FROM AUTHOR]

In the present investigation, the effect and role of plasma gas flow rate on the formation of microstructure, weld defects and plasma modes during plasma arc welding of Ti6Al4V titanium alloy were studied using microscopic examinations, energy dispersive spectroscopic analysis, tensile tests and microhardness measurements. Plasma gas flow rate influences the arc pressure, arc constriction and stability. The transformation of plasma arc from conduction mode to keyhole mode causes severe changes to the microstructural characteristics of the titanium welds. This transformation takes place with small variations of PGFR. The formation of excess weld metal out of weld bead observed at the bottom of the weld is attributed by the formation of keyhole. The macrostructural examination shows that the weld geometries increases and weld defects such as lack of penetration and porosity decreases with increase in the PGFR. The microstructural examination shows that there are various phases formed during variation in PGFR. Acicular α and Widmanstätten α were observed considerably in all the welded joints. Strength of the welded joints and hardness increases with increase in plasma gas flow rate. In the joint welded with 1 L/min, there is formation of α-case which is an oxygen rich brittle subsurface structure and found detrimental to the ductility of the joints. [ABSTRACT FROM AUTHOR]

We characterized the tensile behavior of sclera, optic nerve (ON), and ON sheath in eyes from donors with glaucoma, for comparison with published data without glaucoma. Twelve freshly harvested eyes were obtained from donors with history of glaucoma, of average age 86 ± 7 (standard deviation) years. Rectangular samples were taken from anterior, equatorial, posterior, and peripapillary sclera, and ON sheath, while ON was in native form and measured using calipers. Under physiological temperature and humidity, tissues were preconditioned at 5% strain before loading at 0.1 mm/s. Force–displacement data were converted into engineering stress–strain curves fit by reduced polynomial hyperelastic models and analyzed by tangent moduli at 3% and 7% strain. Data were compared with an age-matched sample of 7 published control eyes. Optic atrophy was supported by significant reduction in ON cross section to 73% of normal in glaucomatous eyes. Glaucomatous was significantly stiffer than control in equatorial and peripapillary regions (P < 0.001). However, glaucomatous ON and sheath were significantly less stiff than control, particularly at low strain (P < 0.001). Hyperelastic models were well fit to stress–strain data (R2 > 0.997). Tangent moduli had variability similar to control in most regions, but was abnormally large in peripapillary sclera. Tensile properties were varied independently among various regions of the same eyes. Glaucomatous sclera is abnormally stiff, but the ON and sheath are abnormally compliant. These abnormalities correspond to properties predicted by finite element analysis to transfer potentially pathologic stress to the vulnerable disk and lamina cribrosa region during adduction eye movement. [ABSTRACT FROM AUTHOR]

The 3 K and 6 K (meaning that 3000 or 6000 carbon filaments are contained in one bundle) carbon fibers were embedded by pure aluminum sheets to have a sandwich composite structure under the accumulative roll bonding method. The tensile and cupping tests were carried out to reveal the strengthening mechanism of carbon fibers embedded in the aluminum+carbon fibers composite sheets. The improvements of ultimate tensile and cupping strengths of aluminum+carbon fibers composite sheets reached to be as high as 48 % and 38 %, compared with that of as‐received sheets. With the detailed observation of the tensile and cupping fractures, the underlying strengthening mechanism comes from the bridging effect of carbon fibers during tensile and cupping tests. The accumulative roll bonding method was approved to be an effective way for aluminum+carbon fibers composite sheets preparation with higher tensile and cupping strength. [ABSTRACT FROM AUTHOR]

This study explores the mechanical properties of a novel composite material, blending polylactic acid (PLA) with sea shells, through a comprehensive tensile test analysis. The tensile test results offer valuable insights into the material's behavior under axial loading, shedding light on its strength, stiffness, and deformation characteristics. The results suggest that the incorporation of sea shells decrease the tensile strength of 14.55% and increase the modulus of 27.44% for 15 wt% SSP (sea shell powder) into PLA, emphasizing the reinforcing potential of the mineral-rich sea shell particles. However, a potential trade-off between decreased strength and reduced ductility is noted, highlighting the need for a delicate balance in material composition. The study underscores the importance of uniform sea shell particle distribution within the PLA matrix for consistent mechanical performance. These results offer a basis for additional PLA-sea shell blend optimization, directing future efforts to balance strength, flexibility, and other critical attributes for a range of applications, including biomedical devices and sustainable packaging. This investigation opens the door to more sustainable and mechanically strong materials in the field of additive manufacturing by demonstrating the positive synergy between nature-inspired materials and cutting-edge testing techniques. [ABSTRACT FROM AUTHOR]

This investigation is effort to enhance the mechanical properties on friction stir welded Al-Mg alloy with different processing levels like tool pin profiles, tool rotational speed and welding speed and the other parameters like tool tilt angle and tool axial load is kept constant for all the runs. The tool pin profiles (straight pentagonal cylinder (SPC), straight cylinder (SC) and straight fluted cylinder (SFC)), tool rotational speed (1000, 1300 and 1600 rpm) and tool traverse speed (30, 40 and 50 mm/min) is processing input factors. Those FSWed samples are considered to conduct the mechanical properties like tensile strength and microhardness is investigated. The optical microscope investigations are utilized to identify the finer grain structure on welded Al-Mg alloy. The ultimate tensile strength is attained at the processing levels (1000 and 1600 rpm, 30 and 50 mm/min and SPC and SC). The maximum hardness was attained on the stirred zones of FSWed Al-Mg alloy for the process parameters (1300 rpm, 30 and 40 mm, SFC and SC), respectively. The poorer grain structure was attained on the stirred regions of Al-Mg alloy due to mechanical mixing is not properly maintained by the selected processing parameters. The microstructure of friction stir welded Al-Mg alloy shows the better fine refinement due to enhancing stirring action by the optimal process parameters. [ABSTRACT FROM AUTHOR]

Composite materials are gaining popularity due to their better mechanical qualities and low weight. This study focuses on enhancing forces of flexural and tensile characteristics in epoxy-based composites by incorporating reinforced carbon fibers extracted from pineapple leaves in combination with cobalt filler. The reinforcement of natural fibers in composite materials addresses environmental concerns and contributes to improved mechanical attributes. Hand lay-ups of pineapple leaf fiber (PALF) and epoxy compound by carbon fiber were created proportion of weight (wt%) by adjusting cobalt 0.25 to 1.0 wt%. The flexural strength of PALF is around 101 MPa, and the Tensile strength of PALF is around 92.94 MPa. Whereas the Flexural strength of CF is around 343.54 MPa, and the Tensile strength of CF is around 181.32 MPa. Compared to pure epoxy, 51.25% increased strength and considerable improvement of flexural and tensile specimens. 0.5 wt% inclusion of nano Cobalt filler component confirms favorable strength test findings in PALF/CF epoxy combination. [ABSTRACT FROM AUTHOR]

This study investigates the quasi-static and viscoelastic properties of additively manufactured (AM) PETG reinforced with short carbon fibres. Samples were manufactured using different parameters in terms of the infill pattern, porosity, and annealing condition. Tensile and compressive tests were conducted to determine quasi-static properties such as Young's modulus and toughness, and dynamic mechanical analysis was used under a frequency sweep of 1–100 Hz to describe the viscoelastic behaviour of the composites. The major impacts and responses between the print parameters were quantified using Analyses of Variance (ANOVAs), which revealed the major contributor to each mechanical property. Fractography on the tensile samples using scanning electron microscopy demonstrated fibre pull-out, indicating poor fibre–matrix bonding, but also revealed interfacial bonding between raster lines in the annealed samples. This had a prominent effect on the properties of latitudinal samples where the force applied was perpendicular to the raster lines. Generally, porosity appeared to have the greatest contribution to the variance in the mechanical properties, with the exception of the tensile modulus, where the infill pattern had a more substantial effect. Annealing caused a consistent increase in the tensile modulus of the tested samples, which can be used to support the design and optimisation of AM parts when they are used under specific loading conditions. [ABSTRACT FROM AUTHOR]

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The conventional techniques for producing a socket are time-consuming disproportionate to the significant population afflicted by limb amputations. Although the new manufacturing direct method, the modular socket system (MSS) method, involves reduced labor time, the technique produces sockets with high stiffness that cause discomfort for those with lower limb amputations during walking. This study investigated the tensile characteristics of numerous materials in below-knee prosthetic sockets. Initially, a vacuum molding approach was used to produce the sockets, which involved various polymers and composite materials to improve the prosthesis socket properties. An F-socket device was also employed to ensure efficient production and optimized pressure distribution at the interface between the socket and the residual limb. A SOLIDWORKS® software was then applied to determine the numerical analysis (stress distribution and the maximum internal pressure). The samples from Group E involved utilizing a novel mixture compared to the direct and traditional methods of various materials. This study presents a novel prosthetic limb socket made from a mixture of four carbon fiber layers, utilizing 20% polyurethane resin and 80% acrylic as the matrix. The resulting material demonstrated acceptable stiffness, extended socket life, and reduced curing time. During the patient's gait cycle, peak pressure of 300 KPa was recorded using the F-socket, while SOLIDWORKS® software indicated an internal pressure of 343 KPa, aligning closely with F-socket measurements. The new direct-fit socket design prioritizes comfort and flexibility using materials with reduced stiffness. [ABSTRACT FROM AUTHOR]

Hybrid composites are made by fusing together, typically using resin, a matrix material (typically metal), a fiber, and a filler component. Fibers and particles are encased in a matrix of another material to create modern composites. Natural fiber composites are becoming increasingly popular due to rising awareness of their many practical applications. The debris produced by the seashell farming becomes serious environmental threat. Recent research has centered on the potential applications of this seashell waste. The purpose is to reduce seashell waste that pollutes the coast near Kanyakumari. Agricultural waste, such rice husk, is more accessible than other types of biomass. Conventional materials are weighed more, so lightweight materials can be used as alternatives for the structural components of an automobile. This swatch is made from combination of biocomposite and repurposed seashells. Mechanical tests, including tensile, flexural, impact, and hardness testing, were performed on the prepared samples. The morphological analysis shows good laminar and interfacial connections throughout the structure. The EDAX spectrum shows the presence of elements like silicon, sulfur, and zinc. The EDAX spectrum of C5 hybrid biocomposites (40% rice husk + 10% seashell + 50% polyester resin) has more zinc than silicon. The C2 (10% rice husk + 40% seashell + 50% polyester resin) hybrid composite outperforms other composites in tensile strength (51.47 MPa), Brinell hardness (132BHN), Rockwell hardness (62RHN), impact energy (51.4 J), flexural strength (203.03Mpa), and water absorption (1%). Based on research investigations, hybrid biocomposites made of bio seashell and bio rice husk are superior than standard biocomposites without sacrificing the eco-friendliness of the automobile. [ABSTRACT FROM AUTHOR]

In transportation engineering, road pavement is commonly categorized as either flexible pavement or rigid pavement. The pavement demonstrates a distinct capacity to endure a variety of loads, including compressive and tensile loads. The capacity to endure compressive and tensile forces is extremely important, especially in the field of pavement construction, as it ensures both the longevity and the safety of the pavement. The objective of this study was to evaluate the capacity of hot mix asphalt to endure compressive and tensile pressures. The experimental methodology employed four different wire mesh deployment configurations on hot asphalt mixtures, utilizing three-point flexural test equipment. The data indicates the most effective method for mimicking hot mix asphalt involves adding a wire mesh layer at a depth of 30 mm below the surface of the experimental specimen. The particular modeling method showed a measurement of flexural resistance up to 291.85 kN. The study's findings indicate that the hot asphalt mixture exhibits a state of balance in its capacity to endure both compressive and tensile pressures. Incorporating a wire mesh layer within the middle section of the hot asphalt mixture has been perceived to enhance its ability to withstand tensile loads, hence improving its overall performance. [ABSTRACT FROM AUTHOR]

The present study referred to the lightweight cenosphere filled, and epoxy composites (0, 7.5, 15, and 22.5 vol.%.) developed with the help of the hot compression moulding process. To ensure the strength of composites, the prepared system was analyzed with tensile, flexural, impact properties, and dynamic mechanical characteristics discussed. Cenosphere-filled composites attained the maximum tensile strength of 19.5 MPa, which is 60% better than the neat epoxy. Adding cenosphere particles increases the tensile, flexural, and impact strength at a superior level. Dynamic mechanical analysis revealed that in 22.5 vol.% of cenosphere reinforced composites, energy dissipation and maximum storage modulus of 6 MPa was enhanced. The surface morphologies of the fractured specimens were characterized using scanning electron microscope (SEM). The morphological investigations indicate a good state of particle distribution in the epoxy matrix. [ABSTRACT FROM AUTHOR]

The utilization of 20CrNiMo/Incoloy 825 composite materials as high-pressure pipe manifold steel can not only improve the strength and hardness of the steel, but also improve its corrosion resistance. However, research on the heat treatment of 20CrNiMo/Incoloy 825 composite materials is still scarce. Thus, the aim of this study was to investigate the influence of solid solution treatment on the microstructure and properties of 20CrNiMo/Incoloy 825 composite materials. Firstly, the composite materials were subjected to solid solution treatment at temperatures ranging from 850 to 1100 °C with varied holding times of 1 h, 4 h, and 6 h. Microstructural analysis revealed that the solid solution treatment temperature had a more pronounced effect than the treatment time on the interface decarburization layer, carburization layer, and grain size. It was observed that the carburized layer thickness decreased while the decarburized layer thickness increased with an increase in the solid solution treatment temperature, oil cooling was found to enhance the hardness of the base layer of the composite materials, and the size of the original austenite grains of 20CrNiMo steel and Incoloy 825 increased with an increase in the solid solution treatment temperature. Secondly, the tensile properties, microhardness, and fracture morphology were evaluated after the composite materials underwent solid solution treatment at temperatures between 950 °C and 1100 °C for 1 h. The results indicated that increasing the solution temperature initially led to an increase in tensile strength and elongation after fracture, followed by a decrease; furthermore, the hardness of Incoloy 825 exhibited a declining trend, while the hardness of 20CrNiMo first decreased then increased. Thirdly, the shear properties and interfacial element diffusion of the composite materials were analyzed following solid solution treatment in a temperature range of 950 °C to 1100 °C for 1 h. The findings demonstrated that higher solid solution treatment temperatures induced full diffusion of Cr, Ni, and Fe atoms at the interface and softened the matrix, leading to an increase in the thickness of the diffusion layer and toughening of the composite interface. Therefore, the shear strength increased with an increase in the solid solution treatment temperature. Finally, the optimal solid solution treatment process for 20CrNiMo/Incoloy 825 composite materials was determined to be 1050 °C/1 h oil cooling, following which the composite materials had good comprehensive mechanical properties. [ABSTRACT FROM AUTHOR]

The growing need for sustainable materials in engineering applications has led to increased interest in the use of waste-derived ceramics as reinforcing fillers in polymer composites. This study investigates the mechanical and tribological performance of epoxy composites reinforced with Yttria-Stabilized Zirconia (YSZ) waste ceramics, focusing on the effects of varying ceramic content (0–40 wt.%). The results demonstrate that while the tensile strength decreases with increasing ceramic content, the wear resistance and surface hardness improve, particularly at 20 wt.% YSZ. These findings are highly relevant for industries such as automotive, aerospace, and industrial manufacturing, where the demand for eco-friendly, high-performance materials is growing. This work aligns with the journal's focus on sustainable engineering by offering new insights into the practical application of waste materials in high-performance composite systems. [ABSTRACT FROM AUTHOR]

Nickel foam offers excellent conductivity, a high surface area, and lightweight structure, making it ideal for applications, like battery electrodes, catalysts, and filtration systems. Its durability and corrosion resistance further enhance its performance in various industries. However, few studies focus on the tensile anisotropy of nickel foam and its tensile fracture process. In this study, the anisotropic tensile behavior of nickel foam with varying relative densities has been investigated, along with its tensile fracture behavior using in situ techniques. The tensile properties of nickel foams show strong anisotropy due to the flattening process in the production process. The results show that the tensile properties, including the yield strength, tensile strength, and elastic modulus, increase with the increasing relative density, while the elongation percentage has no relationship with the relative density. The experiment data on tensile strength are in agreement with Gibson's formula and Liu's formula. In situ tensile tests are conducted to explore the microscopic fracture mechanism of nickel foam. The results show that the struts of nickel foam are tensile fractures or shear fractures near the joints, and the fracture process of struts is clearly recorded and analyzed. This study is significant as it provides critical insights into the anisotropic tensile behavior of nickel foam and fracture mechanism, enabling the optimization of production processes and broadening its potential applications. [ABSTRACT FROM AUTHOR]

This paper reports improvement in the tensile, flexural and interlaminar shear strength (ILSS) properties of ADG‐NH2/Epoxy/CFRP composites at low filler content. Five symmetrical CFRP composite laminates were prepared through wet layup process assisted by vacuum bagging technique with varying wt% proportions (0.25, 0.5, 0.75 and 1) of ADG‐NH2/Epoxy. Tensile tests, short beam shear test and flexural tests were carried out as per ASTM D3039, ASTM D2344 and ASTM 790‐10 respectively to assess the effect of the ADG‐NH2 functionalized nano additives on their mechanical properties. The variation in ILSS were studied for varying temperatures (room temperature, 35, 50, 75, 85, & 100°C for each type of ADG‐NH2/Epoxy wt% (neat, 0.25, 0.5, 0.75 & 1)) of ADG‐NH2/Epoxy/CFRP composites. The ILSS was enhanced up to ∼27% for 0.5 wt% of ADG‐NH2 reinforced CFRP at room temperature but reduced with the higher concentrations (0.75 wt% & 1 wt%). It was observed that ILSS reduced with gradual temperature variations up to 100°C w.r.t room temperature. But an increment was observed up to 0.5 wt% for ADG‐NH2 for all temperature. Form the test results, it has been recorded an improvement in mechanical properties that is, the elastic modulus by ∼18%, ultimate tensile strength by ∼21%, % elongation at break by∼19% and toughness by∼28% for the 0.5 wt% of ADG‐NH2 graphene nano additive reinforced CFRP composite laminates as compared to neat epoxy CFRP laminates. Results also show the augmentation in the Max load by ∼24%, flexural strength by ∼33%, flexural modulus by ∼43%, and flexural strain by ∼26% were observed for the 0.5 wt% of ADG‐NH2 graphene nano additive reinforced CFRP composite laminates as compared to neat epoxy CFRP composite laminates. Fractographic studies of fractured surface using SEM analyses shows better adhesion mechanisms which supports the augmentation in mechanical properties with addition of amine functionalized graphene to CFRP laminate. Highlights: Reinforcement of amine functionalized (ADG‐NH2) graphene in the epoxy matrix and incorporation with carbon fibers to enhance the interfacial and flexural properties.Evaluation of temperature effects on interlaminar shear strength properties of amine functionalized CFRP compositesImprovements in tensile, ILSS and flexural properties observed for a low percentage (0.5 wt%) of ADG‐NH2 graphene reinforced CFRP composite laminates.Use of aerospace grade epoxy and resin with amine functionalized graphene for further use in aerospace industry applications. [ABSTRACT FROM AUTHOR]

This article discusses the mechanical evaluation of recycled PETG filament for 3D printing. The authors emphasize the importance of plastic recycling and the potential of 3D printing in manufacturing. They focus on PETG as a leading material for 3D printing and examine the feasibility of recycling PETG for additive manufacturing. The study demonstrates that PETG 3D printing waste can be effectively recycled into new filament with promising mechanical properties. The research aims to contribute to the understanding of sustainable usage of PETG in 3D printing and inform future efforts in optimizing recycling processes. Another document provides information on the mechanical properties and testing of a specific material used in 3D printing. The material is tested in two different forms, filament and pellets, to compare their characteristics. The testing includes tensile, compression, and impact tests, with results showing slight differences between the two forms of the material. The document also describes the equipment used for the testing process. Additionally, another document presents the results of a study on the behavior of PETG filament in 3D printing when comparing specimens printed from new material versus recycled material. The study conducted compression, tensile, and impact tests on the specimens. The findings indicate a marginal difference in stiffness, with recycled material exhibiting slightly higher stiffness and increased brittleness. However, caution is advised in drawing definitive conclusions based on this initial data, as the sample size was small and only one recycling cycle was examined. Further research is needed to understand the effects of recycling on material [Extracted from the article]

Ulexite and colemanite filled acrylonitrile-butadiene-styrene parts are manufactured by injection molding method. Tensile and wear tests are applied to reveal specific properties of composite parts. Various characterization methods are used to confirm the filler-matrix interactions, polymer melt flow, friction mechanisms, and fracture modes. This study investigated the use of ulexite and colemanite as fillers in acrylonitrile-butadiene-styrene composite parts, focusing on their impact on mechanical and frictional properties. Results showed that the addition of ulexite and colemanite fillers significantly improved mechanical properties such as compared to pure ABS, however ulexite filler showed much better performance compared to colemanite. In terms of wear test, ulexite filled ABS specimen showed a smooth wear while pure and colemanite filled ABS provided severe wear characteristics. These findings have implications for the development of high-performance composite materials for use in industries such as automotive and aerospace. [ABSTRACT FROM AUTHOR]

This study explores the effect of chemical treatment on the physical, mechanical, and morphological properties of two kinds of sisal geotextiles treated with potassium hydroxide and coated with bitumen emulsion. Physical characteristics like mass per unit area, yarn properties, thickness, water absorption and mechanical properties, including tensile, tearing, and puncture strength, were examined. The findings showed significant enhancements in tensile strength (up to 54.90%), tearing strength (up to 103.81%), and puncture strength (up to 32.2%) of emulsion-coated untreated, emulsion-coated alkali-treated and alkali-treated geotextiles, respectively. Furthermore, the alkali-treated emulsion-coated geotextile had the highest mass per unit area with the least water absorption. Morphological, elemental, and crystallographic analyses complemented these outcomes. [ABSTRACT FROM AUTHOR]

Copyright of Electronic Components & Materials is the property of Electronic Components & Materials and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The indispensable development of composites has changed the material trend, specifically in the engineering field, due to the combinations of more than one material in one structure, resulting in the improved permutation of properties such as toughness, high-temperature stability, good wear resistance, high strength and stiffness. This investigation is focused on fabricating the lightweight aluminium alloy composite reinforced with fly ash, and its mechanical and thermal properties were improved by the introduction of different weight percentages (1 wt%, 3 wt% and 5 wt%) of bioceramic silicon nanoparticles (SiNPs) through the gravity stir cast technique. The composite density was evaluated by Archimedes' principle and found lightweight. The influences of multi-reinforcements and the nature of the particle distribution in the aluminium alloy matrix were analysed by scanning electron microscope (SEM), and the peaks of compounds were noted by X-ray diffraction analysis (XRD). The SEM result reveals an even distribution of fly ash particles with few agglomerations identified as various peak points of major compounds like aluminium (Al), silicon dioxide (SiO2), magnesium oxide (Mgo), titanium dioxide (TiO2), alumina (Al2O3) and calcium oxide (CaO). The sample 4 hybrid nanocomposite shows the maximum tensile strength and hardness of 198 ± 1.03 Hv and 77 ± 1.22 Hv, respectively. The results from DSC analysis, 5 wt% of fly ash/1 wt% bioceramic SiNP-reinforced aluminium alloy composite (sample 2), found good thermal conductivity compared to other constitutions. The thermal adsorption effect on aluminium alloy nanocomposite (sample 4) with 15 wt% fly ash/5 wt% bioceramic SiNPs content shows the maximum thermal stability on low mass loss. [ABSTRACT FROM AUTHOR]

This study evaluates the effects of sodium hydroxide (NaOH) treatment on tensile properties of sugar palm 'ijuk' (SPI) fibre-reinforced polymer (FRP) composites, with and without an open hole that acts as a stress concentrator. The NaOH treatment is aimed to improve the interfacial adhesion between SPI fibres and polymer matrix. Composite specimens were prepared using the hand lay-up method, incorporating SPI fibres in various orientations, and featuring a 6 mm diameter hole. Tensile tests were conducted to evaluate the mechanical performance of SPI FRP composite, including ultimate tensile strength, Young's modulus, and elongation at break. The research also compared the properties of SPI to those of synthetic glass fibre in fibre-reinforced polymer composites. The results showed that NaOH treatment significantly improves the fibre-matrix adhesion with 26% increase in tensile strength, leading to enhanced tensile properties in both samples, regardless of hole presence. The 0° orientation provides the highest strength and stiffness when the load is applied in the direction of the fibres. While for the 90° orientation, strength reduces by 14%. The impact of the hole on stress concentration and the subsequent mechanical behaviour of the open-hole specimens is substantial. The findings of this study offer insightful perspectives on the potential use of NaOH-treated SPI fibre in structural and other applications, demonstrating its ability to withstand tensile stresses, even with geometric discontinuities like holes. [ABSTRACT FROM AUTHOR]

The significance of biosilica in the silver-grey magnesium (SG-Mg-10% Si) metal is to enhance its mechanical and tribological characteristics. The Bermuda grass was used to make the biosilica. This investigation employed SG-Mg-10%Si and biosilica reinforcement (0, 5, 10, 15, and 20 wt. %) as the composite matrix. Due to increased bonding between the components of the composite, the SG-Mg-10%Si/biosilica composite created by the stir casting process demonstrated remarkable mechanical and tribological qualities. Further testing was done to assess the mechanical and tribological characteristics of the composite specimens, including density, porosity, hardness, tensile strength, and wear rate. SG-Mg-10%Si was contrasted with all these outcomes. The density plummeted at a rate of 1.49 (g/cm3) when the weight percentage of biosilica particles was added. Minimum and maximum hardness values for the composite's 20% of reinforced biosilica particles are 93.4 VHN and 125 VHN, respectively, and the tensile strength is 633.18 MPa. In order to determine the wear rate of SG-Mg-10%Si/biosilica composites, a dry sliding pin-on-disc tribometer was employed. When biosilica particles were added, the rate of wear of the manufactured SG-Mg-10%Si/ biosilica composites gradually reduced. When subjected to loads of 40 N and sliding distances of 1500 m and 2500 m, respectively, the composite with 20wt.% of biosilica reinforcement had improved anti-wear properties of 10.257 mg/m × 10−3 and 13.334 mg/m × 10−3. Field emission scanning electron microscope (FESEM) was utilized to examine how reinforcement was distributed across the matrix and showed the uniform distribution and strong bonding in the composites, together with a visible biosilica reinforcing interface. The benefits of the SG-Mg-10%Si/biosilica composites are enhanced mechanical and tribological properties and utilized in several applications like automobile, aeronautical and space research, sports goods, and medical types of equipment, reduced expenditure, and saved manufacturing time and exertion. [ABSTRACT FROM AUTHOR]

Background: Laser metal deposition (LMD) is a widely used additive manufacturing technique for producing complex high entropy alloys with special properties for several applications. The AlCoCrFeNiCu HEAs compositional design has six elements with a configurational entropy of 1.79 R and atomic concentrations between 5 and 35%, so the HEA system is thermodynamically favorable according to Boltzmann's theory, attributed to the core effects. However, the high-entropy alloy has dominant Body-Centered Cubic structures which may be too brittle to be examined in tension experimentally. Preheating the substrate before and during layer deposition could be a potential solution that is currently under development since tensile loading necessitates an understanding of a material's behavior under tension through an analysis of its yield and ultimate tensile strength. A computer-aided design (CAD) solid model was used to generate the near-net dog-bone form of the alloy with moderately complicated geometrical characteristics using laser metal deposition (LMD) technology. This study investigates a straightforward and effective computational model for simulating material properties, using COMSOL Multiphysics 5.4 software for laser-deposited high entropy alloys that are excessively brittle to be tested in tension. The AlCoCrFeNiCu high-entropy alloy "dog bone" test sample was modeled using COMSOL Multiphysics for tensile loading. The first principal stresses and longitudinal strain under axial loading conditions were measured using a three-dimensional (3D) structural mechanics' model. Results: The results showed the ultimate tensile strength is 8.47 N/m2, attributed to the high entropy effect and the dominant phase structure of the alloy. Conclusion: Numerical models in this paper demonstrate the effect of stresses on the tensile behavior of the AlCoCrFeNiCu high-entropy alloy. The model optimizes the LMD process by analyzing residual stresses and predicting tensile strength, thus, providing insights that show the potential of high entropy alloys for structural integrity in aerospace applications. [ABSTRACT FROM AUTHOR]

Laser Powder Directed Energy Deposition (LP-DED) can produce thin-wall features on the order of 1 mm. These features are essential for large structures operating in extreme environments such as regeneratively cooled nozzles and heat exchangers, which often make use of refractory metals. In this work, the mechanical behavior of LP-DED C103 was investigated via quasi-static tensile testing and low cycle fatigue (LCF) testing. The effects of vacuum stress relief (SR) and hot isostatic pressing (HIP) heat treatments were investigated for specimens in the vertical and horizontal build orientations during tensile testing. The AB and SR properties were lower than literature values for wrought and laser powder bed fusion (L-PBF) bulk components but higher than electron beam powder bed fusion (EB-PBF). The application of a HIP cycle improved strength by 7% and ductility by 27% past the initial as-built condition. Fracture images reveal that interlayer stress concentration sites are responsible for fracture in specimens in the vertical orientation. Meanwhile, fracture in the horizontal specimens mainly propagates at a slanted angle typical of plane stress conditions. The LCF results show cycles to failure ranging from 100 cycles to 8000 cycles for max strain levels of 2% and 0.5%, respectively. Fractography on the fatigue specimens reveals an increasing propagation zone as max strain levels are increased. The impact of these findings and future work are discussed in detail. [ABSTRACT FROM AUTHOR]

The strain-hardening geopolymer composite (SHGC) is a new type of fiber concrete with excellent ductility and environmental friendliness. However, the high cost of fibers greatly limits its widespread application. This paper proposes the use of untreated low-cost polyvinyl alcohol (PVA) fibers and polyethylene (PE) fibers to develop a low-cost, high-performance SHGC. Axial compression and axial tension tests were conducted on the SHGC with different PE fiber volume fractions (1%, 1.5%, and 2%) and different PVA fiber replacement ratios (0%, 25%, 50%, 75%, and 100%) to investigate the hybrid effects of fibers with different surface properties and to reveal the mechanism of fiber hybridization on the mechanical behavior of SHGCs. The results show that increasing the PE fiber volume fraction improves the compressive and tensile ductility of the SHGC while increasing the PVA fiber replacement rate impacts the strength indicators positively due to the good interface effect formed between its hydrophilic surface and the matrix. When the PVA fiber replacement ratio is 100%, the compressive strength (93.4 MPa) of the SHGC is the highest, with a 21.1% increase compared to the control group. However, the tensile strength shows a trend of first increasing and then decreasing with the increase in the PVA fiber replacement ratio, reaching the highest at a 25% replacement ratio, with a 12.5% increase compared to the control group. Furthermore, a comprehensive analysis of the economic and environmental performance of the SHGC indicates that a 25% PVA fiber replacement ratio results in the best overall economic benefits and relatively low actual costs, although the effect of fiber hybridization on carbon emission indicators is not significant. This paper provides new ideas and a theoretical basis for designing low-cost SHGCs. [ABSTRACT FROM AUTHOR]

Extended exposure to seawater results in the erosion of the structural high-strength steels utilized in marine equipment, primarily due to the infiltration of hydrogen. Consequently, this erosion leads to a decrease in the mechanical properties of the material. In this investigation, the mechanical responses of Q690 structural high-strength steel specimens were investigated by considering various hydrogen charging parameters, such as the current density, charging duration, and solution concentration values. The findings highlighted the significant impacts of electrochemical hydrogen charging parameters on the mechanical behaviors of Q690 steel samples. Specifically, a linear relationship was observed between the mechanical properties and the hydrogen charging current densities, while the associations with the charging duration and solution concentration were nonlinear. Additionally, the fracture morphology under various hydrogen charging parameters was analyzed and discussed. The results demonstrate that the mechanical properties of the material degrade with increasing hydrogen charging parameters, with tensile strength and yield stress decreasing by approximately 2–4%, and elongation after fracture reducing by about 20%. The findings also reveal that macroscopic fractures exhibit significant necking in uncharged conditions. As hydrogen charging parameters increase, macroscopic necking gradually diminishes, the number of microscopic dimples decreases, and the material ultimately transitions to a fully brittle fracture. [ABSTRACT FROM AUTHOR]

Due to the requirements of high stiffness and impact strength of HDPE pipes, in this article, long fiber reinforced HDPE were developed and the effects of fiber length, volume fraction, types, and matrix/fiber interface on the mechanical properties were investigated. Tensile properties, notched impact strength, as well as microstructures were tested. The results showed that fibers increased the tensile strength, modulus, and impact strength, but decreased their plastic deformation. Larger fiber fraction indicates more fibers are involved in load bearing, but easy agglomeration. With ascending fiber length, tensile, and impact strength first increased and then decreased, whereas tensile modulus first increased and then maintained an almost constant value. Carbon fibers showed no advantages over glass fibers and basalt fibers in reinforcing HDPE due to the relatively poor interface bonding strength. Interface modification with KH550 improved the mechanical performance of composites, but the enhancement was limited. More effective methods should be developed for better performance. Highlights: Fiber increases strength and modulus, but decreases plastic deformation.Critical fiber length for basalt LFT is 2.6 mm obtained from SEM.Larger fiber volume and length lead to agglomerations.Difference in BF, CF, and GF reinforced HDPE is determined by interface.Interface modification enhances mechanical properties of LFT but limited. [ABSTRACT FROM AUTHOR]

The article presents the results of the technical–economical study regarding the optimization of fused deposition modeling (FDM) parameters (the height of the layer deposited in one pass—Lh and the filling percentage—Id) for the manufacture of Polyethylene Terephthalate Glycol (PETG) and Acrylonitrile Styrene Acrylate (ASA) parts. To carry out this technical–economical study, was used the fundamental principle of value analysis, which consists of maximizing the ratio between Vi and Cp, where Vi represents the mechanical characteristic, and Cp represents the production cost. The results of the study show that for tensile specimens made of PETG, the parameter that significantly influences the results of the Vi/Cp ratios is the height of the layer deposited in one pass, (Lh), and in the case of the compression specimens made of PETG, the parameter that significantly influences the results of the Vi/Cp ratios is filling percentage (Id). In the case of specimens manufactured via FDM from ASA, the parameter that decisively influences the results of the Vi/Cp ratios of the tensile and compression specimens is the filling percentage (Id). By performing optimization of the process parameters with multiple responses, we identified the optimal parameters for FDM manufacturing of parts from PETG and ASA: the height of the layer deposited in one pass, Lh = 0.20 mm, and the filling percentage, Id = 100%. [ABSTRACT FROM AUTHOR]

Friction stir welding (FSW) is a remarkable green solid-state joining process and it has been proven to be capable of joining advanced materials, such as aluminum matrix composites (AMCs) with sound-quality of joints. As a result, FSW is widely used in many sectors such as aviation, automotive, marine, and structural applications. So far various researchers carried out studies on joint characteristics of FSW and reported better microstructural and mechanical properties. This review study emphasizes various joint characteristics of AMCs namely microhardness, tensile, wear, and microstructural properties of joints obtained by FSW. Also, research work carried out by several researchers in the field of FSW for joining AMCs is summarized. In addition, future trends and challenges in joining of AMCs using FSW is presented. [ABSTRACT FROM AUTHOR]

This manuscript proposes a hybrid method to predict the optimal nano‐metal matrix composites. The proposed hybrid technique is the wrapper of the Fire‐Hawk Optimizer (FHO) and Spiking Neural Network (SNN). Commonly it is known as FHO‐SNN method. The main objective of the proposed method is to improve the method parameters for better enhancement in mechanical properties. FHO approach is used to improve the process parameters of stirring squeeze casting method. The SNN predicts optimal parameters. Moreover, the problem based on the casting is reduced. By then the proposed hybrid technique performance is performed in the MATLAB platform and associated with various existing approaches. The proposed system shows the high tensile strength, impact energy and hardness compared with other existing methods. [ABSTRACT FROM AUTHOR]

This paper outlines an experimental investigation into the durability of large-scale adhesively bonded joints with a thick layer of methyl methacrylate adhesive (MMA). Ageing has been performed by immersion in a 3.5 wt% NaCl solution for 10 weeks at 50°C. Two aged and one unaged specimen were subjected to tensile testing, and three aged and one unaged specimen were loaded up to ~ 3.5 million fatigue cycles followed by a residual tensile test. The ductility of the adhesive is affected by ageing and fatigue testing. Despite a decrease in ductility, the plastic zone development was adequate for the required strain redistribution without compromising the joint performance (strength and stiffness) demonstrating the fatigue tolerance of the joint. The shear, longitudinal, and peel strain values in the adhesive bulk are evaluated by digital image correlation. The shear strength values are significantly higher than the requirements following from the design. All specimens failed by sudden delamination of the composite plate. Post-mortem analysis showed no corrosion travel at the interface of steel and adhesive. [ABSTRACT FROM AUTHOR]

The use of mineral reinforcements in polymer matrix composites has emerged as an alternative for sustainable production, reducing waste and enhancing the physical and mechanical properties of these materials. This study investigated the impact of the melt flow index (MFI) of HDPE and the particle size of two mineral reinforcements, Bahia Beige (BB) and Rio Grande do Norte Limestone (CRN), on the composites. All composites were processed via extrusion, followed by injection, with the addition of 30 wt.% reinforcement. Chemical analyses revealed similar compositions with high CaO content for both minerals, while X-ray diffraction (XRD) identified predominantly calcite, dolomite, and quartz phases. Variations in the MFI, reinforcement type, and particle size showed a minimal influence on composite properties, supported by robust statistical analyses that found no significant differences between groups. Morphological analysis indicated that composites with lower MFI exhibited less porous structures, whereas larger particles of BB and CRN formed clusters, affecting impact resistance, which was attributed to poor interfacial adhesion. [ABSTRACT FROM AUTHOR]

Composite materials find extensive usage in industrial applications. However, they are susceptible to gradual damage over time. In this study, we explored the cracking processes in jute fiber-reinforced composite sheets subjected to uniaxial tension at varying displacement speeds (10, 20, and 30 mm/min) using Abaqus software. The composite plate dimensions are 25×35×10 mm³, with a 7 mm crack length. Our findings indicate that crack propagation in vehicle plates is influenced by mechanical properties relative to load, specifically through increased travel speed. We observed stress concentration around the crack, and the displacement speed significantly affects crack behavior. The cohesive J-integral was derived through finite element analysis, revealing a 90.90% relative error in the mean absolute value ΔJ across the five integral paths for the two sample types. Subsequently, five potential end conditions were assessed for further analysis, considering different boundary conditions: Simply supported (SSSS), two opposing sides clamped (SFSF), Clamped-Simply-Clamped-Simply (SCSC), two opposing sides clamped (CFCF), and all sides clamped (CCCC). Additionally, three different types of tensile actions in the y-direction were considered. [ABSTRACT FROM AUTHOR]

Parts with interior voids created by the LPBF process are known to have the potential to cause fracture when subjected to mechanical loading. In this research, the key process parameters such as laser thickness (LT), scanning speed (SS), and laser power (LP) were taken into consideration to avoid the void formations which was the major reason for affecting the structural integrity. So, void formations (V), ultimate tensile strength (UTS) and reduced modulus (RM) were considered as the response parameters in this study. The entropy-associated weighted aggregated sum product assessment (WASPAS) approach was implemented to examine the favorable conditions which substantiated that the LT is the most influential parameter in nucleation of voids. The verification experiments prove that the void formation was reduced by 98.6% and the UTS and RM were enhanced by 52.17 and 31.7%. [ABSTRACT FROM AUTHOR]

Copyright of Iraqi National Journal of Earth Sciences is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Conductive polymer composites (CPCs) are manufactured by compounding conductive particles with a polymer matrix. There are many applications where they are used, including light-weight applications requiring both electrical and heat conductivity. Carbon nanotubes (CNTs) have been accepted as common materials to accomplish this goal. As part of this research, a material extrusion additive manufacturing (AM) process was utilized to create nanocomposites by a 3D-printing technique. Multi-wall carbon nanotubes (MWCNTs) were mixed in 1, 3 and 6 wt fractions with acrylonitrile butadiene styrene (ABS) and extruded in filament form. Three-dimensionally printed specimens were used to evaluate electrical, electromagnetic interference shielding effectiveness (EMI SE) and tensile properties. The electrical conductivity of the material was 26 times greater than that of ABS. In the X-band of electromagnetic waves, EMI SE's reflected and absorbed portions increased respectively 4 and 16 times. The tensile strength and modulus were enhanced by 15% and 9%, respectively. On composite specimens, microwave heat treatment was applied. There is less void space between the rasters and layers, which helps improve tensile properties. Additionally, 3D-printed specimens were tested for melt flow rate (MFR) and dynamic mechanical behaviour. The nozzle has experienced some wear due to the intrinsic abrasive nature of CNTs. [ABSTRACT FROM AUTHOR]

The tensile behaviour dependency on the process parameters of blended nonwoven fabric is highly non-linear. This paper explores the potentiality of fuzzy logic inference in such a nonlinear environment as predictive process modelling with minimal experimental data. A model based on fuzzy inference engine has been attempted using recycled polyester fibre blend percentage, needling density and depth of needle penetration as the input variables and tensile strength in both machine direction (MD) and cross direction (CD) as the output variables. Proposed model was built in MAT LAB/Simulink and has been verified by experimental sample data set. Mean relative error percentage and correlation coefficient between the fuzzy model predicted and actual experimental sample values were found to be around ±2.5% and up to 0.97 respectively. These results validate that the model may be applied with high accuracies for the prediction of tensile behaviour of the blended nonwoven fabric in the textile industries. [ABSTRACT FROM AUTHOR]

Aluminium alloys have a wide range of applications, mainly due to their advantageous strength-to-weight ratio, denoted as specific strength and corrosion resistance. In recent decades, there has been a notable surge in the usage of recycled alloys, attributed to their reduced production costs and emissions. One of the conditions for secondary production is the optimal sorting of used scrap. Once the aluminium scrap has been melted, it is tough to reduce the content of the various additives. Copper is the primary alloying element in some aluminium alloys, which leads to an increased amount of copper in the aluminium scrap. Therefore, it is important to investigate its effect on the properties of aluminium alloys in which it is not commonly present. For this reason, this paper is concerned with the influence of copper on the microstructure and properties of the secondary aluminium alloy AlZn10Si8Mg. Specifically, it compares two melts of self-hardening AlZn10Si8Mg alloys differing in copper content (0.019% and 1.72%). A complex quantitative and metallographic analysis by optical and electron microscopy has been performed. Mechanical properties were investigated by tensile test, Brinell hardness, and Vickers microhardness measurements. The corrosion resistance of the individual melts was verified by the Audi test. [ABSTRACT FROM AUTHOR]

Globally, millions of tons of construction waste are generated annually, primarily due to the booming construction sector. Among this waste, brick residues are the most prominent. This research aimed to study the properties of mortar with the partial substitution of fine aggregate by brick residues. An experimental methodology was used, involving mortar samples with 10%, 20%, 30%, and 40% brick residue content. These samples were subjected to both mortar and masonry tests. The results indicated that the mortar sample with 10% brick residue performed best. Compared to conventional mortar, this sample showed a 1.58% increase in compressive strength, a 3.99% increase in flexural strength, and a 15.61% increase in tensile strength in mortar tests. In masonry tests, the same sample demonstrated a 12.19% increase in compressive strength in prisms, a 33.20% increase in bond strength, and a 3.82% increase in diagonal compressive strength. In conclusion, substituting fine aggregate with up to 10% brick residues is feasible and optimally improves the mechanical properties of mortar. [ABSTRACT FROM AUTHOR]