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Abstract Cellular materials have drawn increasing interest in numerous applications due to their promising specific stiffness, strength and energy absorption capacity. In this work, a variety of rather novel lattice topologies pertinent to additive manufacturing are derived and examined. A number of these are derived by free-domain and constrained domain topology optimization procedures, while others are inspired by the triply periodic minimum surface (TPMS) sheet-based topologies. The topology optimization module utilized a single objective function of minimizing strain energy under linear elastic conditions. A total of fifteen different lattice topologies are investigated numerically, including both novel and conventional topologies (e.g. strut-based lattices) and their effective elastic properties are determined with respect to relative density through finite element analysis (FEA). Based on the preliminary FEA results, a number of these topologies are selected of which tessellated lattice structures are fabricated through laser powder bed fusion (LPBF) additive manufacturing technique out of Nylon thermoplastic material. The tessellated lattice structures are experimentally tested in compression and their mechanical performance, including uniaxial modulus, yield strength, and energy absorption capacity (EAC), is assessed. FEA simulations have been conducted using an elastic-plastic constitutive model for the Nylon base material. Both the experimental and numerical results reveal that the mechanical performance of the novel tube-based TPMS lattice P-100 and the combined loading (CL) topology derived through free-domain topology optimization surpasses all other topologies. P-100 uses a primitive TPMS with equal-length tubular connections in each direction, where the tubular length percentage compared to the primitive lattice size is 100%, while CL lattice topology is a free domain topology optimized under compressive loads on the centers of faces, edges, and vertices toward the center. The innovative lattice topologies proposed in the current study, particularly the P-100 and CL topologies, can become crucial in applications where it is necessary to improve the energy absorption capacity, such as sandwich panel cores, supports, and infills for 3D printed components. [ABSTRACT FROM AUTHOR]

This study aims to find suitable fatigue assessment methods for welded structures (cover plates and T‐joints) subjected to axial and bending loading. The Hot Spot Stress (HSS), 1‐mm stress (OM), Theory of Critical Distances (TCD), Stress Averaging (SA), and Effective Notch Stress (ENS) methods are evaluated in terms of accuracy and reliability. The evaluation is based on fatigue test data extracted from the literature and carried out in this study. It is found that the SA method can be used to assess the fatigue strength of cover plate joints under axial loading with relatively good accuracy and low scatter, followed by the ENS method. The HSS, TCD, SA, and ENS methods are conservative estimation methods for T‐joints under bending, while the accuracy is low. Furthermore, fatigue design curves applicable for T‐joints under bending are discussed, which can be used in the TCD method and SA method. [ABSTRACT FROM AUTHOR]

Failure assessment diagrams (FADs) are essential engineering tools for evaluating the structural integrity of components. However, their widespread application can be limited by complexity and computational expense. This study presents a novel machine learning-based approach to streamline FAD analysis, offering accuracy and efficiency while overcoming these limitations. The approach integrates numerical contour integral-based FADs with artificial neural networks (ANNs). To ensure reliable material modeling for the Finite Element Analysis (FEA) used to generate J -integral based FADs that train the ANNs, careful experimental and numerical procedures were employed. This involved uniaxial tensile tests, an iterative method for obtaining precise true stress–strain curves, and a Ramberg–Osgood material model for accurate material behavior representation. The ANNs themselves not only analyze large datasets to generate precise FAD envelopes but also predict limit loads and the Φ parameter, incorporating the effect of residual stress on the FAD methodology. To verify and test the proposed method, hypothetical fitness-for-service assessment cases were conducted, incorporating experimental residual stress measurements from split-ring tests on P110 and L80 pipes. These assessments were compared to both traditional FAD methods and computationally intensive FEA-based FADs. Results demonstrate a closer agreement with FEA-based calculations than traditional methods provided in engineering standards. Ultimately, this work provides a rather innovative and adaptable approach for structural integrity evaluations and critical engineering assessments through the proposal of an ANN enhanced FAD approach, simplifying these calculations while maintaining high fidelity. • Developed an ANN-based approach for streamlined Failure Assessment Diagram (FAD) analysis. • Integrated ANNs with numerical FADs, enabling precise envelope generation from extensive datasets. • Conducted experimental residual stress measurements using split-ring test data as an input for hypothetical fitness-for-service (FFS) evaluations. • Demonstrated superior accuracy of the ANN-based FAD methodology for enhanced fitness-for-service (FFS) evaluations. [ABSTRACT FROM AUTHOR]

• Effect of minimal surface-lattice core topological features on the impact properties of a sandwich structure. • Cell size and relative density of minimal surface-lattice core show exponential growth with impact properties of sandwich structures. • The high shear resistance of periodic primitive TPMS topology contributed to improved perforation limit. • Stochastic and spinodoid-based lattice sandwich panels are damage tolerant. Recent advancements in 3D printing technologies have made it possible to fabricate intricate lattice architectures with high precision. These lattices can now be utilized to design lightweight sandwich structures that serve multiple functions. To enhance the impact loading performance of these structures, it is crucial to understand how the lattice's topological properties, particularly those with minimal surface attributes like periodic or stochastic Primitive and Gyroid triply periodic minimal surfaces (TPMS) and spinodal-like stochastic cellular materials, associate with the mechanical properties of sandwich structures while keeping the skin thickness fixed. Thus, this paper explores the low-velocity impact behavior of various sheet/shell-based minimal surface-latticed cores of sandwich structures with woven composite skins. The elasto-plastic-damage numerical simulations consider lattice core periodicity, randomness, and anisotropy while keeping the relative density constant. Core lattice randomness and anisotropy are designed using the Gaussian Random Field (GRF) method for spinodal-based stochastic cellular materials and stochastic TPMS. The simulation results showed that the periodic Primitive-lattice core exhibits high out-of-plane shearing strength, enabling the sandwich structure to demonstrate the highest perforation limit. GRF spinodal-based core achieved the highest peak load due to its anisotropic mechanical properties. However, the post-yielding bending of the lattice sheet limited its ability to resist perforation, and absorb and dissipated energy. Interestingly, the stochastic Gyroid TPMS topology, with its inherent densely-distributed microstructure, showed high sensitivity to loading rate, resulting in enhanced energy absorption and dissipation of the sandwich structure. These findings offer valuable insights for optimizing multifunctional sandwich structures with superior impact performance and their design for additive manufacturing. [Display omitted] [ABSTRACT FROM AUTHOR]

We provide a novel investigation that demonstrates the synthesis of silver-doped bismuth oxide (ABO), holmium-doped bismuth oxide (HBO), nanostructured bismuth oxide (BO), and silver-holmium co-doped bismuth oxide (CDBO) by a cost-effective and straightforward surfactant-assisted co-precipitation technique. In comparison to the BO, ABO, and HBO samples, the optical tests revealed that the CDBO sample exhibited superior photocatalytic characteristics. This is possibly attributed to the physical, optical, and structural properties of the material tailored by the synergistic effect of the adopted strategies, i.e., nanotechnology, oxygen vacancies, and co-doping. The microstructures, physicochemical properties, morphological characteristics, and compositional attributes of the synthesized materials were investigated using sophisticated characterization techniques. The intrinsic conductivity of the bismuth oxide was enhanced with the incorporation of Ag and Ho as co-dopants, as shown by the results obtained from two probe current-voltage experiments. The co-doped sample exhibited the highest efficacy in decomposing rhodamine B dye, with a degradation rate of 91 % during a mere 70-min exposure to W-lamp illumination. The most ideal settings for CDBO photocatalytic activities were identified by comprehensive parameter optimization research. These parameters include a basic pH, a catalyst dosage of 25 mg, a dye concentration of 15 ppm, and an operating temperature of 30 °C. The co-doped and nanostructured photocatalyst also showed an outstanding capability to break down orange II and phenol dye. The trapping experiments' results indicate that the hydroxyl and superoxide radicals play a significant role in the mineralization of the tested dye. [Display omitted] • Co-doped Bi 2 O 3 NPs have been prepared via wet route. • Synthesized samples were characterized via PXRD, FTIR, SEM, BET, and I–V studies. • Co-doping create structural defects and reduced the band gap. • Current-voltage study confirms improved current conductivity. • Co-doped Bi 2 O 3 effectively mineralized the RhB, Orange II and phenol dye. [ABSTRACT FROM AUTHOR]

Hydrogen (H), emerging as a sustainable and promising clean energy source, holds significant potential for transitioning towards a H-based economy, offering a cleaner alternative to traditional fossil fuels. However, hydrogen embrittlement (HE) poses a substantial obstacle to this transition, impacting critical sectors such as transportation, defense, energy production, and construction. Computational modeling, driven by the continuous development of new algorithms and high-performance computing platforms, emerges as an attractive avenue to unravel and address the complexities associated with HE. In particular, a multidisciplinary modeling approach shows potential in investigating the intricate interactions between H and materials across different temporal and spatial scales. Over the last few decades, there have already been many developments in computational modeling investigations based on a coupled study of H diffusion, deformation, and fracture processes to address multifaceted aspects of the HE problem. This comprehensive review sheds light on these advancements, providing insights into the modeling methodologies adopted in these investigations and their results. The review begins with a concise overview of commonly adopted mechanisms to explain HE. Thereafter, the discussion shifts to various advancements in H diffusion modeling, from early works to most recent developments, encompassing diverse aspects, such as H uptake and diffusion through the lattice structure and the role of microstructural traps and material microstructure. The last section of the review focuses on several theoretical and numerical studies that simulate how H affects the fracture characteristics and mechanical properties of various metals and alloys. This discussion includes applications of various state-of-the-art fracture models to predict H-assisted crack growth, as well as a range of theoretical models, continuum-based finite element simulations, and micro-meso scale modeling studies. • Advances in hydrogen diffusion modeling using coupled deformation-diffusion models. • Comprehensive review of coupled deformation-diffusion-fracture models. • Insights into micro-meso scale investigations to study hydrogen embrittlement mechanisms. [ABSTRACT FROM AUTHOR]

In this study, the Time-Temperature-Crystallinity Superposition Principle (TTCSP) was applied to determine the viscoelastic behavior of Thermo-rheological Complex Materials (TCM), specifically Carbon fibre/Poly-Ether-Ketone-Ketone (CF/PEKK) composites. The study investigated the effects of various parameters on the viscoelastic behavior of the composites, such as the degree of crystallinity after different melting temperatures, relaxation, and crystallization times. The TTCSP was utilized on the relaxation data to generate great-grand master curves for the degree of crystallinity for different laminate lay-ups. Hot press forming was employed to manufacture samples under different processing conditions, including various melting and cold crystallization temperatures. Differential Scanning Calorimetry (DSC) was employed to calculate the degree of crystallinity of CF/PEKK composites, while the Dynamic Mechanical Analyzer (DMA) was used to obtain the relaxation data. The generated great-grand master curves proved effective in predicting the relaxation behavior of the composites consolidated using single and double hold cycles at different melting temperatures and crystallization times, respectively. The great-grand master curves presented in this study can serve as valuable tool to calibrate key viscoelastic and/or thermo-viscoelastic material models for aerospace-grade CF/PEKK composites. These models are crucial for simulations aimed at predicting residual stresses and process-induced deformations during the thermoforming process. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pyramidal lattice structures (PLS) with I-shaped struts were 3D printed via DLP. • The utilization of I-shaped struts led to an increase in energy absorption of up to 68%. • Lateral buckling of the lattice struts was observed in the tailored PLS. • The measurements and observed collapse modes were in good agreement with FE predictions. • Specific cross-sectional designs can achieve enhancements in strength of up to 93%. This study examines the compressive response of geometrically tailored pyramidal lattice structures composed of struts with I-shaped cross-sections. Geometrically tailored pyramidal lattices with micro-scale features are 3D printed using the Digital Light Processing (DLP) technique, and their effective elastic modulus, collapse strength and energy absorption capacity are experimentally evaluated under quasi-static compressive loading. Furthermore, detailed non-linear finite element (FE) calculations are performed to examine underlying collapse mechanisms and explore the vast design space offered by the proposed geometrical tailoring scheme. Both the experimental and numerical results show that the geometrically tailored lattice structures outperform conventional pyramidal lattices of equal weight in terms of elastic modulus (+24 %), collapse strength (+21 %) and energy absorption (+68 %). Notably, these strength improvements are attributed to lateral buckling that prompts the I-shaped struts to bend sideways during collapse. Specific cross-sectional designs demonstrate remarkable enhancements in strength and energy absorption, reaching up to 93 % and 161 %, respectively, differentiating them significantly from conventional designs. [ABSTRACT FROM AUTHOR]

Sulfide stress cracking (SSC) is a leading cause of failure in sour service environments, where the presence of wet hydrogen sulfide (H 2 S) causes hydrogen embrittlement and significantly influences the performance and lifespan of casing and tubing pipes. This work presents a numerical investigation on predicting the onset and growth of SSC in a sour environment using a coupled deformation–diffusion phase-field finite element framework, which incorporates the role of sub-surface hydrogen concentration due to H 2 S exposure and mechanical loading effects on the crack growth response. The numerical results agree with the experimental data from the notched slow strain rate testing performed on high-strength low alloy steel (HSLA) in a sour environment at room temperature. Recently, the oil and gas industry has been heading towards unconventional gas well applications that expose crucial parts of a well construction, such as production casings, to high internal pressures and a sour environment. To simulate such conditions, a numerical study is conducted that examines the onset and growth of SSC in pre-notched pressurized pipes subjected to H 2 S exposure. The geometry and boundary conditions used for the pre-notched pipes adhere to the API 579 standard for fitness for a service assessment of equipment containing identified flaws or damage. The findings of this comprehensive numerical investigation provide valuable insights into the effectiveness of a coupled phase-field approach for SSC and demonstrate its potential as an engineering tool for structural integrity assessments that consider environmental effects. • Application of a deformation-diffusion phase-field approach to predict SSC. • Accurate prediction of strength reduction due to SSC. • Influence of H 2 S exposure on crack growth response. [ABSTRACT FROM AUTHOR]

To create a human-like skin for a robotic application, current touch sensor technologies have a few drawbacks. Electrical Impedance Tomography (EIT) is a candidate for this application due to its applicability over complex geometries; nevertheless, it has accuracy concerns. This study employs artificial neural networks (ANNs) to investigate the accuracy and capability of EIT-based touch sensors. A finite element (FE) model is utilized to solve the forward EIT problem while simultaneously determining the system's comprehensive mechanical response. The FE model is comprised of a polyurethane (PU) foam domain, a conductive spray layer and a set of sixteen electrodes. To replicate the process of touching the sensor body, a punch of varying diameters and touch forces is utilized. The mechanical response of the sensor body is modeled using the hyperfoam material model calibrated through experimental uniaxial and shear test data, while the electric conductivity of the sprayed skin surface is obtained experimentally as function of applied strain. The viscoelastic behavior of the PU foam material is also obtained experimentally. These experimental data were implemented in the FE model through user subroutines to model the mechanical and electrical properties of the sensor in the EIT forward problem. The traditional EIT inverse problem image reconstruction was replaced utilizing ANNs as an alternative to extract mechanics based parameters. The ANNs were created to predict the spatial coordinates of the touch point, and they were proven to be extremely accurate. Using the EIT voltage readings as input, the ANNs were utilized to forecast the system's mechanical behavior such as contact pressure, contact area, indentation depth, and touching force. • Coupled electro-mechanical finite element model for solving the EIT forward problem. • Representative material model for Polyurethane (PU) foam based on compression and shear tests. • Relation between mechanical stretch and electrical conductivity incorporated in the FE model. • Detailed mechanical behavior of the sensor obtained through the model for multiple touch scenarios. • Artificial Neural Networks (ANNs) used to predict touch location and mechanical behaviors. [ABSTRACT FROM AUTHOR]

• An initial yield surface is established and proposed for cellular materials. • Five loading cases are considered to evaluate the performance of the yield surface. • Five sheet-based triply periodic minimal surface lattices are investigated. • The proposed yield criterion shows accurate yielding predictions for all cases. Triply periodic minimal surfaces (TPMS), which are a class of architected cellular materials, have attracted significant attention lately, due to their prevailing mechanical, electrical and chemical properties, to name a few, and due to the advancements in additive manufacturing technologies that make it possible to print such materials. However, simulating the elastic-plastic mechanical behavior of structural systems (e.g., beams, plates, cores of sandwich panels, structural systems with various levels of geometric complexity) that are latticed with thousands of TPMS lattices are computationally expensive to model explicitly, and hence the need to develop accurate yield surfaces in order to capture their plastic behavior in a homogenized approach. In this work, a generalized initial yield criterion is proposed for sheet-based TPMS lattices, which incorporates the Lode parameter L. The initial yielding of five different sheet-based TPMS lattices are investigated in five different loading conditions. These lattices are Schoen's I-WP (IWP-s), Gyroid (GYR-s), Diamond (DIA-s), F-RD (FRD-s) and Primitive (PRIM-s). The proposed yield criterion accurately predicts the initial yielding of all these lattices in all the loading conditions considered, outperforming other yield criteria currently proposed in literature. [Display omitted] [ABSTRACT FROM AUTHOR]

• The use of carbon allotropes-MXenes composites (CAMCs) as nanofillers in polymer coatings is surveyed. • CAMCs synergistically enhanced the nanofiller and reinforcement properties of carbon allotropes and MXenes. • CAMCs fill the surface micropores and cracks and avoid/delay the diffusion of corrosive species. • The CAMCs formulations manifest magnified durability as well as anticorrosive potential and excellent dispersibility. • CAMCs are chemically and thermally very stable and can be used for high-temperature practices. Carbon allotropes, especially CNTs and GO, and MXenes are well-known for their filler and reinforced properties in polymer coatings. They fill the surface micropores and cracks of rapture coating structures and avoid the diffusion of corrosive species. They also avoid the direct attack of corrosive species by delaying their diffusion rate. However, carbon allotropes and MXenes manifest poor dispersibility as well as interfacial interactions that limit their use. Recent studies suggest that a suitable combination of carbon allotropes and MXenes (CAMs), synergistically enhanced their reinforcement property. The CAMs formulations manifest magnified durability as well as anticorrosive potential. As CAMs are chemically and thermally very stable, they can be used to formulate effective anticorrosive polymer-based coatings for high temperature application. This article aims to describe the challenges and opportunities of using CAMs as fillers in polymer coatings. The mechanism of reinforcement has also been reported along with future directions. [ABSTRACT FROM AUTHOR]

Owing to the advancements in additive manufacturing and increased applications of additively manufactured structures, it is essential to fully understand both the elastic and plastic behavior of cellular materials, which include the mathematically-driven sheet lattices based on triply periodic minimal surface (TPMS) that have received significant attention recently. The compressive elastic and plastic behaviors have been well established for many TPMS latticed structures, but not under multiaxial loading. Furthermore, TPMS lattices are computationally expensive to model explicitly when used in latticing various structures for enhanced multi-functionality, and hence the need to develop accurate yield surfaces in order to capture their plastic behavior in a homogenized approach. The majority of previous yield surfaces developed for cellular materials originate from cellular foams, and limited attempts has been made to develop yield surfaces for TPMS lattices. In this study, a numerical modeling framework is proposed for developing the initial yield surface for cellular materials and is used to develop the initial yield surface for Schoen's IWP sheet-based TPMS cellular lattices. The effect of different loading conditions on the effective yield strength of the IWP sheet-based (IWP-s) TPMS lattice is numerically investigated, based on a single unit cell of IWP-s under fully periodic boundary conditions, assuming an elastic-perfectly plastic behavior of the base material, for relative densities (ρ ‾) ranging from 7% to 28%. In order to account for different loading conditions, the stress state is characterized in a generalized fashion through the Lode parameter (L). The effect of L is studied over a range of mean stress values (σ m) to understand the effect of both L and σ m on the effective yield strength. An initial yield surface is developed incorporating the effect of L , σ m and ρ ‾ , and is validated numerically showing rather good agreement. In the 3D principal stress space, the shape of the yield surface for the IWP-s lattice resembles the shape of a cocoa pod. [Display omitted] • Extensive numerical finite element simulations on Schoen's IWP triply periodic minimal surface. • An initial yield surface is established and proposed for cellular materials, accounting the third deviatoric stress invariant J 3 , through the incorporation of Lode parameter L. • The initial yield surface is validated at three different loading cases, and is compared to other three well established yield surface for cellular materials. • Proposed yield surface has predicts the initial yielding of IWP-TPMS markedly well. [ABSTRACT FROM AUTHOR]

• Enhanced flexural properties of four point bend (4 PB) beam specimens through relative density gradation and hybridization based on TPMS topologies. • Strategies for gradation and hybridization deduced through stress state in 4 PB beam. • Hybridization and relative density gradation schemes is accomplished based on level-set functions of stretching-dominated TPMS sheet-based lattices. • Numerical results are validated through 4 PB testing on additive manufactured beams. • Enhanced flexural stiffness achieved by combining relative density gradation and hybridization with several different TPMS topologies. Due to the recent boom in digital design for additive manufacturing and 3D printing, there has been a significantly growing interest in latticed structures for light design and improved mechanical properties. However, the focus in the literature has mostly been on compressive mechanical properties of uniformly latticed structures with little emphasis on flexural properties of latticed-beams that are functionally graded and hybridized with different lattice topologies. Therefore, this paper aims to explore the effect of lattice relative density gradation and hybridization on the specific flexural properties of prominent sheet-based triply periodic minimal surfaces (TPMS) cellular four-point loaded beams. First, the effective elastic properties of the cubic porous topologies are evaluated computationally to converge to certain sheet-based TPMS cellular structures capable of providing high flexural properties. Schwartz primitive (P) revealed high stiffness to shear loading, meanwhile, the F-Rhombic Dodecahedron (FRD) showed better resistance to uniaxial loading, and the Diamond (D) showed well-combined uniaxial and shear moduli. The selected four-point bend (4 PB) latticed-beams are functionally graded following a bilinear pattern and hybridized through the span of their length inspired by the shearing force and bending moment diagrams arising in the 4 PB beam, in view of the effective elastic properties of the TPMS topologies. The additively manufactured AlSi10Mg uniform, functionally-graded, and hybridized latticed-beams are tested in four-point bending and the results are compared with the finite element results. Both the experimental and numerical outcomes show good agreement within the elastic-plastic regime. From experimental results, it is found that functional grading and hybridization can considerably enhance the specific flexural modulus of sheet-based TPMS latticed-beams. Also, relative density gradation within the four-point bend specimens proved very essential in deflecting crack growth thereby retarding the final failure, meanwhile hybridization is conveyed to mitigate shear-band failure. Combination of functional gradation and hybridization on the latticed-beams resulted in a significant increase in the specific flexural stiffness. Therefore, this study provides guidelines on how to enhance the flexural properties of lightweight beams through lattice functional grading and hybridization. [Display omitted] [ABSTRACT FROM AUTHOR]

This study investigates stress‐based fatigue assessment methods to determine their applicability to welded cover plate joints subject to axial and bending loading. The nominal stress (NS), hot spot stress (HSS), 1 mm stress (OM), effective notch stress (ENS), theory of critical distances (TCD), and stress averaging (SA) methods are covered, and their accuracy and reliability are evaluated. To the best of the authors' knowledge, there is limited fatigue test data available for cover plate joints subjected to bending loading. In this study, fatigue tests are performed with cover plate joints under axial and bending loading. Evaluation of the fatigue assessment methods is based on the test results. It is observed that for axial loading, the ENS and OM method have the highest accuracy. For bending, the OM method is non‐conservative, and the other methods are overly conservative. Using design curves recommended for thin‐walled welded joints subjected to bending highly improves accuracy. Highlights: This study evaluates fatigue strength assessment methods in terms of accuracy and reliability.This study provides a better understanding about cover plate joints in bending.New test data are generated for high strength steel cover plate joints in axial and bending load.Fatigue strength classes are recommended based on experiments. [ABSTRACT FROM AUTHOR]

Concrete, an integral part of a nuclear power plant (NPP), experiences degradation during their operational lifetime of the plant. In this review, the major causes of concrete degradation are extensively discussed including mechanisms that are specific to NPPs. The damage mechanism could be chemical or physical. The major causes of chemical degradation include alkali–aggregate reactions, leaching, sulfate attack, bases and acids attack, and carbonation. Physical degradation is a consequence of both environmental and mechanical factors combined. These factors are mainly elevated temperature, radiation, abrasion and erosion, salt crystallization, freeze–thaw distortions, fatigue and vibration. Additionally, steel reinforcements, prestressing steels, liner plates, and structural steel also experience degradation. The prospective areas in the structural components of the NPP where the degradation could occur are mentioned and the effective solutions to the causes of degradation are highlighted. These solutions are designed to enhance the physical and chemical characteristics of concrete. Some of the major recommendations include addition of mineral substitutes, use of low water-to-cement ratio as well as low water-to-binder ratio, use of low alkali cement, use of special aggregates and fibers, use of corrosion inhibitors, use of cathodic protection, etc. The review concludes with an overview of present methods and possible recommendations used to enhance the quality of concrete towards preventing concrete degradation and increasing the lifetime of NPPs. [ABSTRACT FROM AUTHOR]

Limiting the generation of polymers waste and maximizing their recyclability and recovery have been the main focus of the research and industry in recent years. Recycling of polyamides leads to the loss in mechanical and thermal properties, therefore, in order to reuse recycled nylons, an enhancement in their properties is desired. Enhancing the properties of recycled polyamides by the addition of functionalised graphene nanoparticles (GNPs) was the goal of this study. Recycled PA6/PA6,6 blends and functionalised graphene nanocomposites were prepared using hot-melt extrusion process. Two types of functionalised graphene were used: O2-GNPs and Amine-GNPs. The nanofillers didn't affect the crystallinity of the recycled nylon, while the presence of functionalised graphene increased the thermal conductivity by enabling better heat transfer routes within the polymer. The microstructure of the materials was characterised confirming the successful dispersion but with a slight variation in GNPs/Polymer bonding depending on the functionalisation type. The strong nylon-to-graphene interfacial hydrogen bonding increased the mechanical properties of the recycled nylon nanocomposites. The functionalised nanoparticles slowed down the segmental motion of the polymer chain and decreased the ductility with increasing GNPs contents up to 10 wt%. The overall behaviour of recycled nylon nanocomposites showed dependency on the type of functionalisation and concentration of GNPs with better improvement in the overall properties using 2 wt% Amine-GNPs. These enhanced properties make functionalised graphene/recycled nylon nanocomposites a promising new class of advanced materials. [ABSTRACT FROM AUTHOR]

Because of their many advantages, such as simplicity of handling, affordability, and environmental friendliness, green magnetic nanoparticles (GMNPs) are currently receiving more attention than prevailing magnetic nanoparticles (MNPs). The synthesis and application of GMNPs inspired by biological systems are encouraged by rising ecological consciousness and stringent environmental restrictions and also deal with in detail in this manuscript. The current report presents the biological and environmental uses of GMNPs in-depth. Numerous biomedical applications, including imaging and diagnosis, cancer therapy, immunoassay, genetic engineering, and supported enzymes (proteins and peptides), among others, successfully use GMNPs. The GMNPs would be coupled with tiny sensors, microsystems, and microfluidics modules to boost the signal sensitivity for the identification of environmental contaminants, diseases, poisons, drugs, and trace biomarkers from clinical, environmental, and dietary examples. The GMNPs were essential elements in gene delivery and gene therapy initiatives, among other genetic engineering endeavors. They have also been extensively used for environmental applications such as wastewater treatment, organic pollutants decontamination, electrochemical sensing, industrial and radioactive wastes treatment, pollutant adsorption and removal etc. The use of GMNPs, particularly biosynthesized MNPs, is also believed to be more cost-effective than the majority of regularly used traditional MNPs. In addition, Green magnetic nanoparticles applied as supported enzymes, proteins and peptides catalyst, positron emission tomography, computed tomography, magnetic resonance imaging, theranostics, thermo-chemotherapy, electrochemical immunoassay and efficient detection of coronavirus is a significant issue in modern analytical chemistry and other fields. The opportunities of using GMNPs in the place of traditional MNPs have also been proposed. [ABSTRACT FROM AUTHOR]

This study investigates the biomechanical performance of various dental materials when filled in different cavity designs and their effects on surrounding dental tissues. Finite element models of three infected teeth with different cavity designs, Class I (occlusal), Class II mesial-occlusal (MO), and Class II mesio-occluso-distal (MOD) were constructed. These cavities were filled with amalgam, composites (Young's moduli of 10, 14, 18, 22, and 26 GPa), and glass carbomer cement (GCC). An occlusal load of 600 N was distributed on the top surface of the teeth to carry out simulations. The findings revealed that von Mises stress was higher in GCC material, with cavity Class I (46.01 MPa in the enamel, 23.61 MPa in the dentin), and for cavity Class II MO von Mises stress was 43.64 MPa, 39.18 MPa in enamel and dentin respectively, while in case of cavity Class II MOD von Mises stress was 44.67 MPa in enamel, 27.5 in the dentin. The results showed that higher stresses were generated in the non-restored tooth compared to the restored one, and increasing Young's modulus of restorative composite material decreases stresses in enamel and dentin. The use of composite material showed excellent performance which can be a good viable option for restorative material compared to other restorative materials. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) has high aspect ratios than many nanosize fillers such as carbon nanotubes and clay, besides its better mechanical properties than many polymers; so they are preferred as a filler material in polymer matrix composites. In this study, the effect of GO on the mechanical properties of linear low-density polyethylene (LLDPE) were experimentally investigated. LLDPE-GO nanocomposites were prepared by melt compounding method, and the extruded nanocomposite was shaped by injection molding machine for the mechanical tests. The mechanical properties investigated included tensile properties, fatigue properties, as well as hardness properties. Differential scanning calorimeter (DSC) was employed to study the thermal characterization of the composites. The results revealed that the addition of GO nanosheets indeed had a positive effect on the tensile, fatigue, and hardness properties. The tensile strength, Young's modulus, and Shore D hardness value were increased by 27.4%, 31.3%, and 9%, respectively, with a GO loading ranging from 0 wt.% to 2 wt.%. The addition of GO had a significant effect on the fatigue properties of the composites such as nearly exponential increment in the cyclic numbers. The samples with 2 wt.% of GO could endure up to 106 cycles during the tests, which is 100 times that of pure LLDPE. The morphological analysis via X-ray diffraction (XRD) and transmission electron microscopy (TEM) indicated that GO nanosheets were well exfoliated in the LLDPE matrix. However, there is no significant effect on the melting temperature, crystallization temperature and crystallinity of LLDPE based on DSC result. [ABSTRACT FROM AUTHOR]

The application of scanning electrochemical microscopy has increased recently in corrosion studies. The electrochemical activity image is usually generated indirectly by measuring the rate of reaction of a mediator which is not a part of the studied system. This work aims at developing an experimental technique to use scanning electrochemical microscopy without using electrochemically active species. Galvanic corrosion of ductile cast iron was studied by pulsing both the sample and tip electrode to cathodic and anodic regions. By tuning the pulse parameters, the current response of the tip differs in the vicinity of iron and graphite, leading to the imaging of the oxidation/reduction processes. [ABSTRACT FROM AUTHOR]

Metamaterials are architected cellular materials, also known as lattice materials, that are inspired by nature or human engineering intuition, and provide multifunctional attributes that cannot be achieved by conventional polymeric materials and composites. There has been an increasing interest in the design, fabrication, and testing of polymeric metamaterials due to the recent advances in digital design methods, additive manufacturing techniques, and machine learning algorithms. To this end, the present review assembles a collection of recent research on the design, fabrication and testing of polymeric metamaterials, and it can act as a reference for future engineering applications as it categorizes the mechanical properties of existing polymeric metamaterials from literature. The research within this study reveals there is a need to develop more expedient and straightforward methods for designing metamaterials, similar to the implicitly created TPMS lattices. Additionally, more research on polymeric metamaterials under more complex loading scenarios is required to better understand their behavior. Using the right machine learning algorithms in the additive manufacturing process of metamaterials can alleviate many of the current difficulties, enabling more precise and effective production with product quality. [ABSTRACT FROM AUTHOR]

This article presents a nonlocal gradient-enhanced damage model that uses direction-dependent damage evolution and interfacial damage to predict transgranular and intergranular cracks in polycrystalline materials at the microstructural level. The distinct grains within the polycrystalline morphology are modeled as anisotropic linear elastic domains with random spatial orientation and cubic symmetries. Transgranular micro-cracks are assumed to occur along specific preferential cleavage planes within each randomly oriented crystal and are described using a bulk damage variable. For intergranular fracture, a smeared description of interface decohesion is incorporated through an interface damage variable which depends on the modified interface kinematics based on a cohesive law that uses a smoothed displacement jump approximation. The coupled system of equations in the proposed computational framework is decoupled using an operator-split methodology to ensure a robust and straightforward computational implementation. Several numerical examples are presented, and simulations are performed on single crystal, bicrystals, and polycrystalline domains to demonstrate the capabilities and validation of the proposed model. [ABSTRACT FROM AUTHOR]

[Display omitted] • A methodology is proposed to design novel isosurface strut lattice structure (ISLS) derived from TPMS. • Structural element of ISLS were modeled using beam and solid tetrahedron elements. • Stiffness, Anisotropy index, and fatigue properties were determined. • Anisotropy analysis showed that ISLS exhibit near isotropic behavior for all relative densities. • Low elastic modulus and superior fatigue resistance demonstrate suitability of ISLS as biomaterial scaffolds. This paper proposes a novel methodology to design a family of strut-based lattice structures derived from isosurfaces. Here the methodology is applied on isosurfaces obtained from Triply Periodic Minimal Surfaces (TPMSs). A Schoen's Gyroid TPMS morphology was employed to generate an isosurface strut lattice structure (ISLS). The structural element of ISLSs were modeled as solid tetrahedral and beam elements. Finite element simulations were performed to compute the effective mechanical properties such as stiffness, anisotropy index and fatigue properties for range of relative densities, i.e., 5% to 35%. An isosurface strut mesh sensitivity study was performed to determine number of mesh points required for consistency in mechanical properties. Stretch dominated sheet Gyroids are found to be most superior lattices for mechanical properties in literature and hence the truss based ISLS is compared to sheet Gyroids. The scaling laws demonstrated that Gyroid ISLS modelled with both beam elements and solid elements exhibited bending dominated behavior and yet ISLS solid elements show an elastic modulus, bulk modulus, and shear modulus, comparable to stretch-dominated sheet Gyroids. Anisotropy analysis showed that ISLS exhibit near isotropic behavior for all relative densities. Results exhibited that for the same relative density, ISLS modelled with beam elements showed lower elastic modulus, but higher fatigue performance as compared to the solid elements. Highly porous, low elastic modulus and superior fatigue resistance demonstrate suitability of ISLS beam as biomaterial scaffolds whereas ISLS solid having high modulus are useful in applications requiring enhanced mechanical strength. [ABSTRACT FROM AUTHOR]

Herein, lanthanide ion (Gd+3) doped Bismuth Molybdate (Bi 2 MoO 6) integrated on the rGO sheets has been prepared as a novel photocatalyst (Gd@Bi 2 MoO 6 /rGO) for the photocatalytic treatment of toxic pollutants. Different physiochemical, optical, electrical, thermal, and electrochemical properties of Gd@Bi 2 MoO 6 /rGO, along with its counterparts (Bi 2 MoO 6 and Gd@Bi2MoO6), were studied through XRD, SEM/TEM, FT-IR, UV/Vis, I-V, TGA, Mott-Schottky, and EIS measurements. Photocatalytic experiments revealed that Gd@Bi 2 MoO 6 /rGO exhibited significantly enhanced photocatalytic activity, achieving 96.2 % photo-degradation of Methylene Blue with 120 min of irradiation, which is 6.5 and 3.1 times higher compared to Bi 2 MoO 6 (40.9 %) and Gd@Bi 2 MoO 6 (64.8 %), respectively. Moreover, Gd@Bi 2 MoO 6 /rGO demonstrated a notable photocatalytic efficiency of 81.7 % towards Ciprofloxacin, significant as per the existing literature benchmark. The enhanced photocatalytic activity is ascribed to the in-built Gd+3 redox centers, high electrical conductivity (7.35 × 10−3 S/m), favorable flat band potential (-0.81 V), and low semiconductor impedance (R ct = 51.71 Ω and R s = 0.90 Ω). Additionally, the electron-capturing ability of lanthanide dopant ions and S-C heterojunction of Gd@Bi 2 MoO 6 /rGO facilitates the separation of photo-generated e-/h+ pairs and favors high concentrations of ROS. The results obtained highlight the potential of Gd@Bi 2 MoO 6 /rGO for applications in photocatalysis and wastewater treatment. [Display omitted] • Gd doped Bi 2 MoO 6 have been prepared via hydrothermal route. • Gd@Bi 2 MoO 6 NPs were reinforced with rGO using ultrasonication approach • Synthesized nanocomposite showed exceptional light harvesting aptitude. • The impedance study confirms the improved charge transport properties. • Newly developed nanocomposite effectively degrades organic pollutants. [ABSTRACT FROM AUTHOR]

• The influence of the S, P, and Si and the δ-ferrite content on the susceptibility of AISI 310S to weld solidification cracking is investigated. • Adequate control of S and P to less than 0.02%, and Si away from 1.5 to 2.5% was found key in preventing solidification cracking. • Benchmarking the case results with the modified Suutala and Pacary curves revealed close outcomes. Solidification cracking is very common in the welding process of austenitic stainless steels and can lead to premature failures. Yet, the main quantitative impact of S, P and Si on solidification cracking is still lacking. In addition, the present solidification cracking prediction diagrams are merely composition based, i.e., C r e q / N i e q dependent. Hence, this work aim to highlight the importance of controlling S, P, Si, and δ-ferrite on the susceptibility of AISI 310S to solidification cracking. Penetrant testing, XRF spectrometry, hardness, ferrite measurements, along with microscopic examination were used. XRF spectroscopy revealed 0.09% S, 0.09% P and 2.27% Si at the weld which are deemed to be in critical range according to the reported literature and ASTM A240. Benchmarking the results with the modified Suutala and Pacary curves revealed close results. Therefore, outcomes from this work can aid in the development of such prediction diagrams, along with improvement to the refining industry. [ABSTRACT FROM AUTHOR]

• Assessing welding distortions in a large structure experimentally and numerically. • Demonstrating the quality in numerical results using simplified CWM techniques. • Identifying the parameters having significant impacts on the welding distortions. Unwanted distortions are typically observed in components after the welding process. Physical trial tests and extra post-treatments are being widely utilized in industries to minimize and correct the out of tolerance distortions. These methods are time-consuming and costly. There has been growing interest in digital tools which have great potential to minimize the physical test loops and corrections. In this study welding distortions analysis has been carried out on a large beam structure experimentally and numerically using computational welding mechanics (CWM) techniques such as the inherent strain (local–global) method and the shrinkage method, together with the lumping approach. The estimated distortions from the shrinkage together with lumping approaches were in good agreement with the experimental measurements and the computational time affordable. The inherent strain (local–global) method captured the trend of distortion with an underestimation of distortions. The accuracy of the estimated residuals stresses from the inherent strain (local–global) approach is higher than the one from shrinkage together with lumping approaches. Moreover, the effects of various welding process parameters (i.e. welding sequence, fixture, and weld pool size) on welding distortions were investigated. It is found that following the proper welding sequence could minimize the welding distortion of the beam structure. Increasing the constraints of fixtures can prevent welding distortion effectively and reducing weld pool size results in less welding distortions of the beam structure. [ABSTRACT FROM AUTHOR]

The thermal enhancement and pressure drop in a circular tube with radially-arrayed winglet vortex generator (VG) mounted inside at different orientations were experimentally studied. A series of four winglet rings containing VGs were on the inner surface of the tube at different sections. The effects of winglet attack angles β (0–45°), pitch ratios PR (1.6–4.8), porosity ratio γ (0–20%), winglet length L (10–20 mm), and inclination angle α (0–30°) on heat transfer and pressure drop characteristics were carefully examined. The study was carried out at Reynolds numbers (Re) ranging from 6 × 103 to 2.7 × 104 nestling in the turbulent flow regime. Results showed a significant effect of the winglets on the heat transfer enhancement and pressure penalty compared to the smooth tube. Experiments further revealed that as the length or attack angle of winglets increased, both Nusselt number (Nu) and friction factor (f) were intensified. When it turned to pitch ratio and inclination angle of winglets, the trend became adverse. By comparing the contribution of different winglet parameters, it is preferable to optimize the pitch ratio (PR) other than length, inclination angle (α) nor attack angle (β) for a higher thermal enhancement. The case of small porosity ratio (γ = 10%) at a low Re yields the maximum thermal enhancement of 1.26. Empirical correlations for Nu and f were generated for the winglets based on experimental data. [ABSTRACT FROM AUTHOR]

[Display omitted] • Quaternary ammonium copolymers having different hydrophilicity/hydrophobicity are tested as casing and tubing corrosion inhibitors. • Polymeric surfactants with higher hydrophobicity showed better protection potential than surfactants with higher hydrophilicity. • They become effective by adsorbing on the metal surface using their hydrophilic segments, and their adsorption follows Langmuir isotherm. • Polymeric surfactants retards both anodic and cathodic reactions and mainly behave as cathodic-type inhibitors. • DFT study suggests that quaternary nitrogens deprotonate and coordinate with the metallic surface using their unshared electron pairs. In this study, two quaternary ammonium-based copolymers (DAC-DAD10 and DAC-DAD20) with varying hydrophilicity/hydrophobicity are synthesized, characterized, and their capacity to suppress P110 carbon steel (P110 CS) corrosion in 3.5% NaCl is examined. DAC-DAD10 and DAC-DAD20 were synthesized using diallylammonium chloride (DAC) and N1, N1-diallyl-N6-dodecyl-N6, N6-dimethylhexane-1,6-diaminium dichloride (DAD) and their inhibition potential (%IE) and mechanism were studied by different experimental and computational methods. The outcomes suggest that the %IE of DAC-DAD10 and DAC-DAD20 increases on increasing the hydrophobicity as DAC-DAD20, having a large hydrophobic alky chain, showed relatively better %IE than DAC-DAD10. DAC-DAD10 and DAC-DAD20 manifest the best %IE of 88.68% and 96.17%, respectively, at concentrations as low as 3 mgL-1. Potentiodynamic polarization studies indicate that they behave as cathodic-type inhibitors. Their adsorption on the metallic surface followed the Langmuir adsorption isotherm. Various surface analyses, including SEM-EDS, and XPS, confirm that they adsorb at the metal and electrolyte interface and build a corrosion protective layer. DFT study suggests that quaternary nitrogen atoms easily deprotonate and coordinate with the metallic surface using their unshared electron pairs. The corrosion inhibition based on experimental and computational analyses is schematically presented and described. [ABSTRACT FROM AUTHOR]

[Display omitted] • Porous bone plates with cubic (C), diamond (BCC) and body-centered cubic (CBCC) structures were prepared. • Axial compression, torsional and bending tests were carried out to check the designs' reliability. • CBCC structure with enhanced performance was used with varying rows' and porosities. • Finite element analysis was used to check the biomechanical performance of bone plates. • Increased porosity enhanced the callus volume but displayed poor mechanical performance. The current study investigates the biomechanical performance of porous bone plates augmented with three different cellular lattice structures, e.g., body-centered cube (BCC), simple cube (SC), and the superposition of simple and body-centered cube (SC-BCC) structures. The SC-BCC cellular structures, exhibiting improved torsional, compression, and bending stiffness, were strategically integrated into the bone plates. Configurations ranging from one to three rows, with porosity ranging from 30% to 90%. Increasing the number of rows and porosity maximized the interfragmentary movement at the fracture site. Specifically, SC-BCC configurations with one, two and three rows at 90% porosity demonstrated callus volume improvements of 31.33%, 42%, and 43.2%, respectively, compared with the lowest callus volume observed with SC-BCC at one row and 30% porosity. Regardless of the improved volume, callus stiffness was highest at 30% and 90% porosity levels across all cases, indicating more mature tissue formation in calluses and better physiological load support. High stresses located at 90% porosity, followed by 50% porosity, discouraged their mechanical performance. Therefore, employing 30% porosity configurations with appropriate vertical rows for desired movement is recommended for optimal biomechanical performance. However, 90% porosity may be suitable in scenarios involving minimal forces and restricted patient movement. [ABSTRACT FROM AUTHOR]

Several carbon steel tubing suffered severe corrosion in service which resulted in the leakage of production fluids from tubing string and, consequently, a decrease of well productivity. Optical metallographic microscopy, X-ray diffraction (XRD), combined with weight loss and characterization methods were used to determine the most probable causes of the failure. The results showed that the composition and structure of the tubing joints and couplings were in accordance with the parameter requirements of API 5CT for grade J55. Upon visual inspection, the corroded pipe exhibited significant thickness reduction in multiple locations, which justifies utilizing the triaxial yield of pipe body formula, assuming the minimum measured thickness as the nominal thickness of the pipe. When compared to the upper bound internal pressure requirements in API 5CT, the equivalent stress calculation showed significantly lower failure pressure levels, which provide strong evidence that the pipe could not withstand actual service conditions. The composition of corrosion products was mainly FeCO 3 and Fe 3 O 4 , and scaling layer were composed of the heavy components of the crude oil, CaCO 3 and corrosion products. The scaling layer was protecting the steel surface from corrosion and reducing the corrosion rate. Once the scaling layer was broken, the corrosion rates increased. Also, pitting corrosion rates simulations were conducted at locations with the highest corrosion risk. Results show that at the first 30 days, pitting corrosion rates are the highest at these locations due to many factors including high CO 2 partial pressures, acidic pH at these locations, and larger production volumes resulting in an increase of wall shear stresses and higher velocities. • Microscopy and X-ray spectroscopy used to investigate carbon steel tubing failure. • Pipe unable to withstand service conditions evident by stress calculations. • The composition of corrosion products was mainly FeCO 3 and Fe 3 O 4. • Pitting corrosion rates first 30 days due to high CO 2 partial pressures, acidic pH, and larger production volumes. [ABSTRACT FROM AUTHOR]

In this study the fatigue strength of fillet welded tube-to-plate joints failing at the weld root and subjected to multi-axial stress states is investigated. The fatigue test data is collected from the literature and it is assessed together with the experimental data generated in this study. Finite element analysis is used to analyze the stress state at the weld root. The fatigue strength estimation capabilities of local stress based methods such as the Principal Stress Hypothesis (PSH), von Mises Stress Hypothesis (vMH), Modified Wöhler Curve Method (MWCM), and Effective Equivalent Stress Hypothesis (EESH) are compared. The applicability of modified Gough Pollard Equation (GPE) in local stress system is also assessed. It is observed that most of the proposed local stress assessment methods can estimate the fatigue strength of fillet welds subjected to multiaxial stress states with constant principal stress direction, e.g. proportional loading. In case of load histories which produce varying principal stress directions with respect to time, e.g. non-proportional loading, better estimation capability is shown by MWCM and EESH. In most of the cases of varying principal stress direction load histories, vMH and PSH fail to estimate the fatigue strength. The fatigue strength of specimens tested with combined loading is reduced in comparison to the fatigue strength of specimens tested with only internal pressure and only bending loading. Out-of-phase loading does not affect the fatigue strength significantly for the specimens in this study. However; a decrease in fatigue strength is observed for the test data for out-of-phase loading collected from the literature. [ABSTRACT FROM AUTHOR]

High density polyethylene (HDPE) can show viscoelastic-viscoplastic behaviors under monotonic loads and a stress softening after reloading under cyclic ones. This sets a challenge in simultaneously representing such response in material constitutive models. In addition, due to the adoption of novel accelerated tests at higher temperatures, e.g., 95 °C, the need for a higher temperature calibration is motivated. Therefore, the objective of this study is threefold: (i) to investigate the capability of the three network viscoplastic (TNV) model in capturing HDPE thermo-viscoplasticity under monotonic and cyclic loads, (ii) to report observations on HDPE at various strain-rates and temperatures from 23 °C to 95 °C including the α-relaxation region (iii) to explore the ratcheting behavior of HDPE, i.e., cyclic creep. The FEA analysis based on the calibrated TNV model was successfully able to predict the HDPE behavior under static, quasi-static and dynamic loads. The predicted strain range Δ ε and mid-range strain ε s of the cyclic creep showed good agreements. This implies that the TNV model can be a reliable candidate for HDPE engineering assessments. Findings of this work will have many industrial applications, e.g., products manufacturers or resin producers, in which HDPE is used under complex loads. Similar procedures can be followed for other thermoplastics which lays the basis for establishing a standard calibration guideline. • The thermal viscoelastic viscoplastic behavior of HDPE under monotonic and cyclic loading conditions are investigated. • A constitutive model was calibrated and validated under static, quasi-static and dynamic cyclic loads. • Observations on HDPE with various strain-rates and temperatures from 23 °C to 95 °C are reported. • The calibrated FEA model was successfully able to capture the cyclic creep behavior of HDPE, up to 500 cycles. [ABSTRACT FROM AUTHOR]

The present study investigates the influence of thermo-mechanical material properties of different steel grades (S355–S960) on welding residual stresses and angular distortion in T-fillet joints. Different cases in which temperature dependent thermo-mechanical material properties are considered as constant, linear, and as a function of temperature are simulated by using finite element (FE) method. Experiments are carried out to evaluate temperature dependent yield stress and Young’s modulus for S700 and S960 steel grades. Furthermore, JMat Pro software is used to obtain the remaining thermo-mechanical material properties. The numerical predictions of angular distortion and transverse residual stresses are validated with experimental measurements. It is observed that for assessment of residual stresses, except yield stress, all of the thermo-mechanical properties can be considered as constant. For the prediction of angular distortions with acceptable accuracy, heat capacity, yield stress and thermal expansion should be employed as temperature dependent in the welding simulations. [ABSTRACT FROM AUTHOR]

Herein, we report the fabrication and characterization of high-strength Kevlar epoxy composite sheets for structural application. This process includes optimization of the curing conditions of composite preparation, such as curing time and temperature, and the incorporation of nanofillers, such as aluminum oxide (Al2O3), silicon carbide (SiC), and multi-walled carbon nanotubes (MWCNT) in different weight percentages. Differential scanning calorimetry (DSC) was utilized to investigate the thermal stability and curing behavior of the epoxy, finding that a minimum of 5 min is required for complete curing under an optimized temperature of 170 °C. Moreover, mechanical characterization, including flexural and drop-weight tests, were performed and found to be in good agreement with the DSC results. Our results show that nanofiller incorporation improves the mechanical properties of Kevlar epoxy composites. Among the tested samples, 0.5% MWCNT incorporation obtained the highest mechanical strength. [ABSTRACT FROM AUTHOR]