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This study proposed a new low-rise bolt–steel plate connection precast concrete sandwich wall structure (PCSWS). Shake table testing was conducted on an experimental model of the bolt–steel plate connection PCSWS with two stories. The experimental phenomenon, failure pattern, displacement response, dynamic characteristics, and global hysteresis were analyzed in detail. The test results revealed that the proposed structure demonstrated excellent seismic performance without any structural cracks when subjected to an excitation intensity level of IX for Model-1. The seismic damage was moderate with no significant structural cracks after an excitation intensity level of IX for Model-2. Cracks in Model-2 occurred in the sequence of the places at the bottoms of the columns, the door corners, window opening corners, and the filled surfaces in the bolt–steel plate connection joint zone on the first floor. The observed damage states were primarily light and moderate, indicating the structure's ability to withstand seismic events. [ABSTRACT FROM AUTHOR]

This research experimentally analyses the fabrication, testing, and development of cement mortar incorporating Polyvinyl Alcohol (PVA) fiber at concentrations of 1%, 2%, and 3% by volume of the total cementitious matrix. PVA fiber geometry with a length of 8 mm and a diameter of 40 µm, specifically the RECS 15/8 mm type, was utilized due to its optimal balance between mechanical performance and workability. Mechanical tests, including three-point bending, were conducted to assess the load–deflection behavior, ultimate strength, and energy absorption capacity of the reinforced beams. The scope of this study encompasses tensile strength, elastic modulus in four-point bending with un-notched specimens, fracture energy in three-point bending with notched specimens, and compressive strength tests. The addition percentages of PVA fibers (1%, 2%, and 3%) were selected to investigate the effect of fiber concentration on mechanical properties systematically and to identify the optimal reinforcement level for enhancing performance. Tensile strength values exhibited a clear enhancement with increasing PVA fiber content, recording 1.96 MPa, 3.17 MPa, and 5.12 MPa for 1%, 2%, and 3% PVA fiber, respectively. The Elastic Modulus, determined through four-point bending with un-notched specimens, demonstrated a notable increase in stiffness, with values of 26.17 GPa, 53.63 GPa, and 67.7 GPa for 1%, 2%, and 3% PVA fiber, respectively. Three-point bending tests with notched specimens revealed improved energy absorption capabilities, as indicated by Fractured Energy values of 1.33 N.mm/mm2, 2.98 N.mm/mm2, and 3.91 N.mm/mm2 for 1%, 2%, and 3% PVA fiber. Furthermore, compressive tests yielded increased strengths, with values of 46.8 MPa, 57.2 MPa, and 73.9 MPa for 1%, 2%, and 3% PVA fiber, respectively. The goal of this research is to explore and quantify the benefits of adding PVA Fibers to cement mortars, focusing on enhancing mechanical properties such as tensile strength, elastic modulus, fracture energy, and compressive strength. The findings are particularly beneficial for developing auxetic cementitious materials, offering applications in advanced structural components, earthquake-resistant structures, protective barriers, flexible pavements and runways, and innovative architectural designs. The results highlight the potential of PVA fibers to significantly enhance the performance and durability of construction materials, paving the way for advanced and resilient building components. [ABSTRACT FROM AUTHOR]

Purpose: A feasible solution to the challenges relevant to urban civilization has been the construction of high-rise buildings. However, the impact of lateral forces like earthquakes and wind is considered important in the design and safety of high-rise structures. These types of structures are especially susceptible to wind. The present study is carried out to examine the vibration performance of different types of lateral load resistance systems against wind loads i.e., moment-resistant frame system, shear walls at the corner and centre of the building, bracing (V type and X type), and tube systems. Method: In the context of this research, a detailed wind analysis is carried out on a diverse set of building models, which encompasses varying numbers of stories, including low-rise (10 storeys), medium-rise (20 & 30 storeys) and high-rise (40 storeys) buildings. The performance of the building models is measured and compared by considering various structural response parameters like storey displacements, base shear, storey drift, and overturning moment. Result: The results showed that shear walls, bracing, and tube systems effectively reduce lateral displacement, Storey drift, and overturning moment in tall structures. The building with core shear walls exhibit superior stiffness and performance, while X-bracing excels in shorter structures. Moreover, the core shear wall performs outbound among all divisions of structural systems by providing adequate performance and stability in structures by reducing the drift and displacement response. Conclusion: The study's outcomes provide valuable insights for selecting optimal structural systems to enhance the safety and performance of tall buildings specifically concerning wind loads in densely populated urban environments. [ABSTRACT FROM AUTHOR]

Timber is arguably the oldest construction materials that human have used since the dawn of civilization. Since the last few centuries, the invention of concrete and steel materials has limited timber uses to small and medium structural applications. The renaissance of timber construction has been felt recently due to the emergence of engineered massive timber elements that can perform similar structurally to that of concrete. The main objective of this paper is to study feasibility using massive timber element in building to be constructed in the futuristic city LINE-NEOM, Saudi Arabia. The main motivation of this study is the sustainability aspect of timber that can contribute to zero carbon emission for buildings, which will be one of the major environmentally friendly goals for LINE. Literature survey was conducted to demonstrate that timber is promising construction material for future building. A comparative case study of multi-story building constructed using traditional reinforced concrete and massive timber elements was performed. One particular type of massive timber element called Cross Laminated Timber (CLT) was used in this study. Key structural performance of building was compared using applicable design code criteria. Furthermore, carbon emission of buildings constructed with reinforced concrete and CLT was analyzed and compared. The structural analysis and design results indicated that the CLT building was acceptable in term of lateral deformation or drift under critical combination of lateral and gravity loads. The carbon emission comparison showed that CLT building outperformed the reinforced concrete building significantly. As was anticipated, the CLT building stored significant amount of carbon making it an excellent alternative materials for buildings in LINE that has goal to be zero-net carbon's city. [ABSTRACT FROM AUTHOR]

Fast, accurate, and high-frequency detection for evaluating pavement structural performance is vital for road maintenance decision-making. Traditional detection methods make it challenging to balance the detection speed, frequency, and cost. Pavement condition identification technology based on vehicle vibration has become increasingly mature and can overcome the above problems. This study aims to evaluate the structural performance of asphalt pavement. A vehicle-based test system based on two-axle vibration sensing was developed. The vibration signal from the vehicle driving in the asphalt pavement was generated. Further, the deep signal features was extracted based on the expression of the probability distribution. The evolutionary characteristics of probability density distribution and cumulative distribution were summarized. The main conclusions are as follows: The theoretical model analyzed the correlation between the probability density and the pavement modulus. Further, estimate the peak of the probability density (PKDE) and the cumulative distribution fitting value (CDF0). The estimated indexes' correlation coefficients were calculated by matching the dynamic deflection index of 10 road sections. As a result, PKDE has a robust correlation with a correlation coefficient of 0.81. Therefore, the vehicle vibration probability distribution expression method proposed is effective for structural performance evaluation and has high application feasibility. [ABSTRACT FROM AUTHOR]

On 14 June 2023, the European Parliament adopted Regulation (EU) 2023/1230 on machinery, which entered into force on 19 July 2023 (with some exceptions as per art. 54, according to a corrigendum issued to address a clerical error as regards the application dates in the original version) and shall apply from 20 January 2027, replacing the Machinery Directive 2006/42/EC. The main innovations/differences introduced by the Machinery Regulation (MR) compared to the Machinery Directive (MD) are critically analysed here, with a focus on sustainability issues. Some of these issues are covered by several international standards (such as BS 8887, ISO 10987 or DIN 91472), which also define the criteria and requirements for the remanufacturing process, although some technical gaps remain. Using the example of agricultural machinery, this paper proposes a methodology for determining the areas of acceptability for remanufactured products: these are expressed in terms of structural performance (e.g., the number of cycles ahead to failure expressed as the mutual of damage 1 − D = 0.625 ) and the functional and safety requirements of the original machine. In this way, the issue of "substantial modification of machinery" is explored in terms of the safety obligations that the remanufactured machinery must fulfil. The paper is therefore a contribution to circular design by providing general criteria for the extension of the service life of machinery while at the same time considering safety issues. [ABSTRACT FROM AUTHOR]

Objective At present, the structural system of prefabricated underground stations in China presents diversified development characteristics, but lacks systematic classification. Therefore, the research progress on the structural performance of open-cut prefabricated underground stations is sorted out. Method Aiming at the current mainstream structure forms, the structural system characteristics of open-cut prefabricated underground stations are systematically summarized. The research on the structural performance of the above stations is organized from prefabricated elements, joint connections and overall structure three levels. The development direction of open-cut prefabricated underground stations is proposed. Result & Conclusion The structure of open-cut prefabricated underground stations can be classified into two categories: prefabricated-monolithic type and fully-assembled type. The research on prefabricated components of assembled underground station mainly focuses on the bearing performance of assembled plate components. The joint connection of prefabricated components is related to the bearing and seismic performance of the overall structure for the prefabricated underground station, and therefore is the focus of the research. The bearing and seismic performance of prefabricated underground structures is mainly investigated by numerical methods, and lacks experimental data on the overall structure. Studies on the load bearing performance of the above station considering the whole life cycle will become an important research direction.

This study explores the influence of different concentrations of recycled concrete aggregate (RCA) on the fresh and hardened properties of self-consolidating concrete (SCC) in order to assess the structural suitability of the use of RCA in a precast concrete plant. The study particularly emphasizes the early strength of the produced concrete. The RCA was sourced from crushed concrete used in roadway applications and was sieved to replicate the characteristics of natural aggregate. Five different SCC mixes were produced, with RCA substituting 0%, 10%, 30%, 50%, and 70% of the natural coarse aggregate (NCA) by weight. For each different mix design, the hardened properties tested were the compressive strength and tensile strength. The fresh properties investigated were the passing and filling ability. Additionally, aggregate properties including grain size distribution and absorption of coarse aggregate were studied. The selected mix design follows a typical well-graded self-consolidating concrete mix with 28-day strength of 8000 psi (55.16 MPa). It was found that replacing up to 50% of the NCA with RCA improves the early strength of concrete without a significant impact on the fresh and hardened concrete properties. [ABSTRACT FROM AUTHOR]

In this paper, the structural performances of steel plate shear walls employing web plates with rectangular, triangular (zigzag), trapezoidal, and sinusoidal corrugation patterns under monotonic loading are investigated. Several significant structural response parameters including buckling stability, stiffness, strength, serviceability, and energy dissipation capability are considered in this research endeavor. The results of this study provide crucial insights into the behavior of corrugated-web steel shear walls with varying infill plate shapes and thicknesses. It is shown that corrugated-web shear walls predominantly undergo local and/or interactive buckling modes, while flat-web systems exhibit more of a global buckling behavior. Additionally, corrugated infill plates substantially enhance the overall capacity of the system, with the rectangular pattern exhibiting the highest strength, surpassing the flat-web panels by approximately 11 times for a 2-mm web-plate thickness. Assessment of the energy absorption capacity reveals the superior performance of the rectangular pattern for web thicknesses between 2.0 and 3.0 mm. From the load–displacement responses, it is found that increasing of the web thickness significantly enhances the strength and stiffness performances and the base shear capacity is improved by 42% while increasing the thickness from 1.5 to 3.0 mm. These results demonstrate the importance of proper design and detailing in ensuring the desirable and high performance of corrugated-web steel shear walls as promising lateral force-resisting systems. [ABSTRACT FROM AUTHOR]

Copyright of Urban Mass Transit is the property of Urban Mass Transit Editorial Office 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.)

Several researchers have studied how impact loads from impact hazards affect reinforced concrete (RC) slabs. There is relatively little research on impact loading effects on pre-stressed structures. The usage of fibers in structural elements intrigued researchers. In this paper, impact-loaded post-tensioned (PT) slabs with and without Forta-Ferro fibers were compared to post-tensioned slabs with plain concrete and conventional shear reinforcement. Forta-Ferro is a lightweight, low-cost fiber, and hence its effects on slab structural response under impact load deserve to be explored. Post-tensioned slabs' impact resistance and energy absorption were tested using real-world situations of rapid and severe loads. Four identical 3.3 by 1.5 m concrete slabs were utilized in the experiment. The experiment involved dropping a 600 kg iron ball from 8 m onto each slab's center of gravity. The slabs' responses were investigated. The four slab configurations were tested for displacement, energy absorption, and cracking. Forta-Ferro fiber reinforcement is understudied, making this study significant. The study's findings may help us comprehend fiber-reinforced concrete PT slabs' impact resistance and structural performance. Engineers and designers of impact-prone buildings like slabs and bridges will benefit from the findings. The study also suggests adding Forta-Ferro fibers to post-tensioned slabs to improve durability and resilience against unanticipated impact hazards. [ABSTRACT FROM AUTHOR]

The research of high‐performance composite pressure vessels in practical application has become the focus of attention, and fiber paths play an important role in the structural performance of composite pressure vessels. Therefore, a method is proposed for determining the optimal geometric parameters of the pressure vessel head shape under a novel variable slippage coefficient non‐geodesic(NVSCNG). First, NVSCNG is used as the dome fiber path design mode, and the classical lamination theory is used to construct a dome stress field model. In addition, on the basis of the Tsai‐Wu failure criterion, the minimum laminate thickness is determined to satisfy the strength constraints. Second, the performance factor (pressure*volume/weight) is used to calculate the structural performance of the dome with variable geometric parameters under the novel variable slippage coefficient fiber path. Moreover, the stability constraints are considered to determine the optimal geometric parameter values of the dome. Finally, the structural properties, stress response and thickness were analyzed under two types of fiber paths based on the optimal dome profile. Results show that compared to the conventional variable slippage coefficient, the performance factor can be maximally improved by nearly 60.94% using the novel variable slippage coefficient, and the thickness of the composite layer at the equator of the dome can be maximally reduced by nearly 34.88%. In addition, the research shows that NVSCNG can improve the structural performance of the dome and realize the lightweight of dome components, which are greatly important in guiding the design of fiber paths for pressure vessels. Highlights: No unconstrained linear problem between NVSCNG and initial winding angle.Optimal dome profile geometry parameters are m = 0.8, rc = 0.5.The dome structural failure is controlled by the longitudinal stresses.Winding angle distribution has a strong influence on dome stress distribution.Higher dimensionless performance factor and lighter mass for NVSCNG. [ABSTRACT FROM AUTHOR]

Ecological networks are an effective strategy to maintain regional ecological security. However, current research on ecological network construction in areas with large-scale resource extraction is limited. Moreover, classic ecological network construction methods do not perform satisfactorily when implemented in heavily damaged mining landscapes. Taking the example of Liaoning Province, China, a framework for stepwise renewal of ecological networks was proposed, which integrates basic ecological sources and other sources that include mining areas. The framework was based on multi-source ecological environment monitoring data, and all potential ecological sources were extracted and screened using an MSPA model and the area threshold method. Further, ecological sources were classified into two types and three levels based on the influence of abandoned mines and the characteristics of ecosystem services in the ecological sources. Ecological corridors were extracted using the MCR model. An ecological corridor optimization process based on combining the gravity model with addition and removal rules of corridors was proposed. The results indicated that the basic ecological network in Liaoning Province included 101 ecological sources and 162 ecological corridors, and the supplementary ecological network included 28 ecological sources and 67 ecological corridors. The ecological sources were divided into two types, and corridors were divided into three types. The basic ecological network exhibited a spatial distribution of discrete connections in the west and close connections in the east. Changes in ecological network topological indicators indicated that a supplementary ecological network strengthened the structural performance of the regional ecological network, expanding spatial coverage, filling hollow areas, and enriching local details of the regional ecological network. Regulation strategies were proposed for ecological sources with different connection modes. The number of ecological sources implementing restrictive development, pattern optimization, and protective development were 101, 12, and 16, respectively. This paper provides a constructing framework of ecological networks adapted for resource-based regions. This method can support decisions for the environmental governance of mines, thus contributing to a balance between resource exploitation and ecological protection in regions. [ABSTRACT FROM AUTHOR]

This paper investigates the structural performance of novel steel-plate concrete containment structures, focusing on third-generation nuclear power plants. To address the challenges of increased complexities and costs associated with double-layer containment designs, this study explores the potential of steel-plate concrete structures to enhance safety, economic efficiency, and construction simplicity. The steel-plate concrete structure, characterized by its core concrete and dual steel plates, shows superior compressive strength, bending resistance, and elastoplasticity. Extensive numerical analyses, including finite element modeling and thermal-stress coupling, were conducted under various load conditions. Under structural integrity test conditions, the maximum radial displacement observed was 24.59 mm. Under design basis conditions, the maximum radial displacement was 47.61 mm; under severe accident conditions, it was 53.83 mm. The ultimate bearing capacity was 0.91 MPa, 2.17 times the design pressure. This study concludes that the steel-plate concrete containment structure maintains a high safety margin under all tested conditions, with stress and strain well within acceptable limits. It can effectively serve as a robust barrier against radioactive leakage and malicious impacts, providing a viable alternative to conventional containment designs. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) concrete printing is increasingly becoming popular because it provides a powerful platform for the fabrication of structural components in freeform architectural shapes. Although manufacturing technology and material property improvement are advancing rapidly, the development of methods to predict the structural capacity of printed elements is lagging. This paper presents an experimental and numerical investigation to predict the axial load capacity of a printed concrete wall module. The module geometry contains two parallel thin wall sections connected by an internal sine wave. The thin wall section reduces the concrete consumption, and the internal sine wave provides lateral stability during printing and in the hardened state. It is a popular pattern printed by many researchers and in some real constructions. Two wall module specimens with the prescribed geometry were 3D-printed and tested under compression. The maximum loads of 2,890 and 2,924 kN were obtained for the first and second wall specimens, respectively. Additionally, samples were taken from different locations of a printed prototype to identify printed material characteristics. These experimental characteristics were then introduced to a finite-element numerical model for predicting the structural performance of the printed wall module under compression load. The results showed that the experimental maximum load and stiffness have 1% and 5% differences with numerical outputs, respectively. Based on such a validated model, the failure modes are discussed, and an analytical method is proposed for predicting the axial capacity for the prescribed geometry. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department 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.)

In a slim-floor structural system, beams and slabs are placed at the same level, reducing the overall floor height and material usage in vertical structures, thereby improving economic efficiency. The use of slim-floor structures is common practice in Finnish construction where these structures are typically constructed using hollow-concrete slabs and welded steel box beams. However, in Finland, only a few buildings utilise cross-laminated timber (CLT) slabs in slim-floor structures, and none have incorporated the composite action between CLT and steel beams. This paper presents the laboratory test results of combining CLT slabs and asymmetric welded box beams (WQ-beams) to further assess their potential in optimising structural performance. The structural behaviour of the test construction was evaluated for serviceability and ultimate limit states. The testing involved six full-scale specimens to observe structural responses by measuring total jack forces, deflections, strains, and slip between timber and steel. Vibration tests were conducted on four specimens, capturing deflection and acceleration during heel-drop and walking tests. Additionally, push-out tests were performed to determine connection properties of the wood screws by measuring jack force and displacements. The same skilled faculty team meticulously carried out all tests in the Structural Behaviour Laboratory at Tampere University in Finland. The comprehensive datasets are presented in Excel sheets along with illustrative graphs. Furthermore, the report contains images taken during and after the tests. The provided dataset can serve construction companies, product developers, and researchers aiming to deepen their understanding of the structural behaviour of steel-timber slim-floor composite structures. Additionally, it can be utilised as a reliable reference to validate finite element models (FEM) and analytical calculation models, and to aid in the development of design guides or standards.

Advancements in wooden manufacture and the inherent sustainable merits of timber have stimulated studies on high-rise wooden structures and their structural performances. Considering the height restrictions of timber structures in Taiwan, two types of hybrid structure systems, reinforced concrete (RC) structure mixed with timber components, were proposed as substitution solutions to explore their feasibility and environmental impact in high seismic zones. A fifteen-story RC structure was adopted as the benchmark building, and building weight, material substitution efficiency, and embodied carbon were thus compared with the proposed hybrid timber structures after determining wind and seismic impacts. The results showed that structure system Type 1, which replaced original RC slabs and RC walls with timber, weighs only 61.3 % of the RC structure, reducing seismic forces by 38.7 % and base shear by 30.6 %, while inter-story drift ratio was smaller than that of RC structure; meanwhile, Type 2, which maintained the original RC service core and replaced timber structure for rest of the area, was only 44.5 % of the structural weight of RC structure, with a reduction of 36.4 % in seismic forces and 21.1 % in base shear. Furthermore, Type 1 featured reduced embodied carbon of 34.8 % and 35.4 % respectively using imported and domestically produced timber, while Type 2 features reductions of 47.4 % and 49.3 % respectively. The study indicated that the RC-timber hybrid structure system not only has significant structural performance in the face of the challenges of high seismic zones but also offers new solutions in terms of environmental sustainability.

Abstract Breakwaters play an important role in in mitigating wave-induced damage to marine structures. However, conventional submerged breakwaters often exhibit limited wave dissipation capabilities, while floating breakwaters may lack adequate safety performance. Therefore, this study introduces a novel combined breakwater design aimed at addressing the shortcomings of both traditional types. The proposed breakwater integrates a floating structure with a trapezoidal submerged breakwater via an anchor chain connection. To evaluate its efficacy, numerical simulations of wave interactions with structures were conducted using the OpenFOAM computational fluid dynamics (CFD) software in a two-dimensional (2D) numerical flume. Dynamic mesh technology was employed to simulate the motion of the floating body, and the resulting wave loads on a box girder bridge deck positioned behind the breakwater were analyzed to assess the combined breakwater’s protective capabilities and influencing factors. Analysis of wave heights and loads on the bridge deck revealed that the combined breakwater outperformed traditional submerged breakwaters in terms of wave dissipation. Furthermore, it was observed that the protective efficacy of the combined breakwater was more sensitive to variations in the size of the floating body compared to the submerged structure, and more responsive to changes in wave period than wave height. Leveraging the ability of the floating body to attenuate waves near the surface and the enhanced impact resistance provided by the combined floating and submerged structures, the proposed breakwater offers a promising approach to improving wave attenuation performance and enhancing safety for coastal infrastructure.

Currently, more than ten ultrahigh arch dams have been constructed or are being constructed in China. Safety control is essential to long-term operation of these dams. This study employed the flexibility coefficient and plastic complementary energy norm to assess the structural safety of arch dams. A comprehensive analysis was conducted, focusing on differences among conventional methods in characterizing the structural behavior of the Xiaowan arch dam in China. Subsequently, the spatiotemporal characteristics of the measured performance of the Xiaowan dam were explored, including periodicity, convergence, and time-effect characteristics. These findings revealed the governing mechanism of main factors. Furthermore, a heterogeneous spatial panel vector model was developed, considering both common factors and specific factors affecting the safety and performance of arch dams. This model aims to comprehensively illustrate spatial heterogeneity between the entire structure and local regions, introducing a specific effect quantity to characterize local deformation differences. Ultimately, the proposed model was applied to the Xiaowan arch dam, accurately quantifying the spatiotemporal heterogeneity of dam performance. Additionally, the spatiotemporal distribution characteristics of environmental load effects on different parts of the dam were reasonably interpreted. Validation of the model prediction enhances its credibility, leading to the formulation of health diagnosis criteria for future long-term operation of the Xiaowan dam. The findings not only enhance the predictive ability and timely control of ultrahigh arch dams’ performance but also provide a crucial basis for assessing the effectiveness of engineering treatment measures.

Breakwaters play an important role in in mitigating wave-induced damage to marine structures. However, conventional submerged breakwaters often exhibit limited wave dissipation capabilities, while floating breakwaters may lack adequate safety performance. Therefore, this study introduces a novel combined breakwater design aimed at addressing the shortcomings of both traditional types. The proposed breakwater integrates a floating structure with a trapezoidal submerged breakwater via an anchor chain connection. To evaluate its efficacy, numerical simulations of wave interactions with structures were conducted using the OpenFOAM computational fluid dynamics (CFD) software in a two-dimensional (2D) numerical flume. Dynamic mesh technology was employed to simulate the motion of the floating body, and the resulting wave loads on a box girder bridge deck positioned behind the breakwater were analyzed to assess the combined breakwater's protective capabilities and influencing factors. Analysis of wave heights and loads on the bridge deck revealed that the combined breakwater outperformed traditional submerged breakwaters in terms of wave dissipation. Furthermore, it was observed that the protective efficacy of the combined breakwater was more sensitive to variations in the size of the floating body compared to the submerged structure, and more responsive to changes in wave period than wave height. Leveraging the ability of the floating body to attenuate waves near the surface and the enhanced impact resistance provided by the combined floating and submerged structures, the proposed breakwater offers a promising approach to improving wave attenuation performance and enhancing safety for coastal infrastructure. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering (17264073) 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.)

Predicting the axial Shortening strength of concrete-filled steel tubular (CFST) columns is an important problem that this study attempts to solve for civil engineering projects. We suggest using a deep learning-based artificial neural network (ANN) model to address this issue, taking into account the intricate relationship between steel tube and core concrete. The model, called ANN-SFRC (Steel Fibre Reinforced Concrete), surpasses an R2 threshold of 0.90 and achieves impressive R2 values across different types of CFST columns. Compared to traditional linear regression methods, the ANN-SFRC model significantly improves accuracy, with an observed inaccuracy of less than 3% compared to actual values. With its reliable approach to forecasting the behavior of CFST columns under axial compression, this high-performance instrument enhances safety and accuracy during the design and planning stages of civil engineering. [ABSTRACT FROM AUTHOR]

In this article, the effect of hooked‐end fibers with different lengths on the structural performance of RC‐FPs fabricated from hybrid fiber‐reinforced self‐compacting concrete (HFR‐SCC) was investigated. For this purpose, a total of 15 full‐scale test samples having different plate thicknesses (60, 70, and 80 mm) were produced and tested under bending after a 90‐day curing period. Subsequently, load‐carrying capacity (Pp), flexural toughness (Fth), and deflection ductility index (μu) of all RC‐FPs were found using load‐deflection curves obtained from bending tests, while crack patterns were drawn from the samples tested. Besides, high‐precision contour plots are proposed to estimate the structural performance values of RC‐FPs depending on plate thickness and fiber reinforcing index. As a result, the best structural performance in RC‐FPs was obtained from the use of a longer hooked‐end steel fiber together with micro steel fiber as a hybrid, followed by the lower length hooked‐end steel fibers as singles. Specifically, irrespective of the plate thickness, the hybrid use of longer hooked steel fibers in combination with micro fibers increased the Pp, Fth, and μu values of RC‐FPs on average 1.67, 1.76, and 1.57 times, respectively, compared to the control specimens. As for when using the lower length hooked‐end fiber as single, the values of Pp, Fth, and μu increased on average 1.57, 1.69, and 1.30 times. Lastly, whereas plate thickness has little effect on improving the structural performance of thin‐walled carrier elements such as RC‐FPs, adding fibers in different lengths, aspect ratios, and combinations is much more effective. The collective test results demonstrate that using RC‐FPs made of HFR‐SCC in the roof carrier system of large span structures could improve structural performance, aesthetics, erection time, and earthquake behavior thanks to reduced dead load. [ABSTRACT FROM AUTHOR]

A new type composite dowel shear connector was proposed by introducing folded angles in the steel dowels. Four push-out specimens and two composite beam specimens were designed and experimentally studied. The structural behavior and failure mechanism of the composite folded dowel shear connection were investigated. The concrete failure was observed in both push-out and flexural tests, and the folded steel dowels were capable of yielding development. It is found that the bearing capacity and shear stiffness of the specimens with denser spacing dowels were higher than that of specimens with sparser dowels, but the ductility and deformation performance of the specimens with denser spacing dowels were lower than those with sparser dowels. By means of the finite element model simulation, the influence of strength and thickness of concrete slab, strength, thickness and folded angle of steel dowel on the mechanical properties of folded dowel shear connection were analysed. The folded angle could be determined as 20° because of the larger actual effective shear area and bearing capacity. Based on the bearing capacity analysis in terms of the three likely failure modes, such as steel failure, concrete shear failure and concrete pry-out, calculation formula of the shear bearing capacity of the folded dowel shear connection was put forward and verified. The calculated results by the proposed formula were in good agreement with the test results. For the composite beams, the calculated bending moments derived from the transformed section and the plasticity section methods were also in good agreement with the test values. It is suggested that the shear connection degree should be greater than 1 to enable a full composite beam. [ABSTRACT FROM AUTHOR]

Hollow structures reduce weight without compromising load-bearing capacity and are widely used. The new Glass-Fiber-Reinforced Polymer high-strength thin-walled inner mold simplifies internal cavity construction and boosts structural performance. This study first investigates the influence of a GFRP high-strength thin-walled circular tube on the cross-sectional load-carrying capacity of hollow slabs. Then, a formula for the bending load-carrying capacity of the section under the action of the tube is derived. The results indicate that when the height of the concrete compression zone meets certain conditions, GFRP high-strength thin-walled circular tubes can improve the ultimate load-carrying capacity of the hollow floor slabs. In order to achieve a more economical design, the bending moment modification of a GFRP high-strength thin-walled circular tube of a continuous slab was studied. Research has found that the bending moment modulation limit for a continuous slab is 35.65% when it is subjected to a load of P u = 24   k N . Experimental analysis has shown that the results are generally consistent with the calculations. In practical engineering, the application of a GFRP high-strength thin-walled circular tube of continuous slabs has limitations. Therefore, this study investigated a GFRP high-strength thin-walled honeycomb core slab and found that its ultimate load-bearing capacity is greater compared to waffle slabs. In addition, the stress performance of the GFRP high-strength thin-walled honeycomb core internal mold is superior, making it more promising for practical applications. [ABSTRACT FROM AUTHOR]

Abstract Non-avialan theropod dinosaurs had diverse ecologies and varied skull morphologies. Previous studies of theropod cranial morphology mostly focused on higher-level taxa or characteristics associated with herbivory. To better understand morphological disparity and function within carnivorous theropod families, here we focus on the Dromaeosauridae, ‘raptors’ traditionally seen as agile carnivorous hunters. We applied 2D geometric morphometrics to quantify skull shape, performed mechanical advantage analysis to assess the efficiency of bite force transfer, and performed finite element analysis to examine strain distribution in the skull during biting. We find that dromaeosaurid skull morphology was less disparate than most non-avialan theropod groups. Their skulls show a continuum of form between those that are tall and short and those that are flat and long. We hypothesise that this narrower morphological disparity indicates developmental constraint on skull shape, as observed in some mammalian families. Mechanical advantage indicates that Dromaeosaurus albertensis and Deinonychus antirrhopus were adapted for relatively high bite forces, while Halszkaraptor escuilliei was adapted for high bite speed, and other dromaeosaurids for intermediate bite forces and speeds. Finite element analysis indicates regions of high strain are consistent within dromaeosaurid families but differ between them. Average strain levels do not follow any phylogenetic pattern, possibly due to ecological convergence between distantly-related taxa. Combining our new morphofunctional data with a re-evaluation of previous evidence, we find piscivorous reconstructions of Halszkaraptor escuilliei to be unlikely, and instead suggest an invertivorous diet and possible adaptations for feeding in murky water or other low-visibility conditions. We support Deinonychus antirrhopus as being adapted for taking large vertebrate prey, but we find that its skull is relatively less resistant to bite forces than other dromaeosaurids. Given the recovery of high bite force resistance for Velociraptor mongoliensis, which is believed to have regularly engaged in scavenging behaviour, we suggest that higher bite force resistance in a dromaeosaurid taxon may reflect a greater reliance on scavenging rather than fresh kills. Comparisons to the troodontid Gobivenator mongoliensis suggest that a gracile rostrum like that of Velociraptor mongoliensis is ancestral to their closest common ancestor (Deinonychosauria) and the robust rostra of Dromaeosaurus albertensis and Deinonychus antirrhopus are a derived condition. Gobivenator mongoliensis also displays a higher jaw mechanical advantage and lower resistance to bite force than the examined dromaeosaurids, but given the hypothesised ecological divergence of troodontids from dromaeosaurids it is unclear which group, if either, represents the ancestral condition. Future work extending sampling to troodontids would therefore be invaluable and provide much needed context to the origin of skull form and function in early birds. This study illustrates how skull shape and functional metrics can discern non-avialan theropod ecology at lower taxonomic levels and identify variants of carnivorous feeding.

On 14 June 2023, the European Parliament adopted Regulation (EU) 2023/1230 on machinery, which entered into force on 19 July 2023 (with some exceptions as per art. 54, according to a corrigendum issued to address a clerical error as regards the application dates in the original version) and shall apply from 20 January 2027, replacing the Machinery Directive 2006/42/EC. The main innovations/differences introduced by the Machinery Regulation (MR) compared to the Machinery Directive (MD) are critically analysed here, with a focus on sustainability issues. Some of these issues are covered by several international standards (such as BS 8887, ISO 10987 or DIN 91472), which also define the criteria and requirements for the remanufacturing process, although some technical gaps remain. Using the example of agricultural machinery, this paper proposes a methodology for determining the areas of acceptability for remanufactured products: these are expressed in terms of structural performance (e.g., the number of cycles ahead to failure expressed as the mutual of damage 1−D=0.625) and the functional and safety requirements of the original machine. In this way, the issue of “substantial modification of machinery” is explored in terms of the safety obligations that the remanufactured machinery must fulfil. The paper is therefore a contribution to circular design by providing general criteria for the extension of the service life of machinery while at the same time considering safety issues.

The use of reinforced concrete shear walls is inevitable in earthquake-resistant building design. For this reason, it is important to understand the effect of shear walls used in buildings designed in earthquake zones on structural behaviour. In addition, it is necessary to reveal the behaviours for linear and non-linear calculation methods in buildings with shear walls. In this article, 12 building models were created in 4 different floor plans with 6, 9 and 12 storeys, having frame structural systems with shear walls, respectively, to represent low, medium and high-rise buildings. Linear and nonlinear (pushover and non-linear time history (NTH)) analyses of the created building models were carried out with the Sta4- Cad program and their linear and nonlinear behaviours were compared. The results obtained from linear structural analyses reveal that if shear walls are placed on the outermost axes, they will become more unfavourable as the building height increases. The results obtained from pushover and NTH analyses show that if the placement of the shear walls approaches the centre, the damage level in the beams increases as the building height increases, in contrast with the damage level in the vertical structural elements decreases. In addition, while the effect of beam damage is greater in the pushover analysis at performance levels, it is seen that the damage effect on vertical structural elements is greater in the NTH analysis. [ABSTRACT FROM AUTHOR]

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Topology optimization is a structural optimization method that mainly works on distributing the material within a design domain based on specific design objectives and parameters. Topology optimization results are often comparable to nature-inspired forms. Hence, this research explores tree-like structures, a key category of nature-inspired forms, through the lens of topology optimization. Nine design domains that differ in their number of columns and branching are used to explore these factors' effect on resulting forms. These nine domains are topology optimized using Grasshopper and its tOpos plugin. Results are then compared based on visual and structural aspects. The study concludes by discussing the potential of using topology optimization as a method for designing tree-like structures and confirming that increasing the number of columns combined with some sort of branching within the structure does improve the final results. [ABSTRACT FROM AUTHOR]

The U-steel support structures of underground caverns are prone to instability and failure under blast loads. The purpose of the underground cavern reinforcement is to mobilise the self-supporting capacity of the surrounding rock to resist the blast. To better understand the mechanical performance and failure mechanism of the U-steel support, the fracture process and vibration behaviour of the support structure under blast loading are investigated by the microseismic monitoring experiment. The dynamic responses of the cavern support structures under blast loading are investigated, and the potentially hazardous sections of the U-steel support structure are revealed by the theoretical analysis. The microseismic monitoring results show that the blast induced microseismic events are concentrated in the arch shoulder of the small chaînage, correspondingly the U-steel structures in this region have been partially extruded and deformed. The failure mechanism of the supporting structure is presented. In order to effectively inhibit the internal fracture evolution or macroscopic failure of the rock mass, the synergetic reinforcement scheme of the structures is proposed. The results of the research can be used as a reference for the design and control method of the U-steel support in similar projects. [ABSTRACT FROM AUTHOR]

Due to their excellent mechanical features, concrete-filled steel tube (CFST) columns are usually employed in high-rise constructions; it is also significant to consider fire safety while designing buildings. The fire-resistance performance of fibre-reinforced CFST columns is superior to that of unreinforced CFST columns under identical conditions. The post-peak behavior of CFST columns can be enhanced by incorporating fibres to reduce the brittleness of concrete. The research on this topic is limited and considerable research gaps are available in the literature. This research examines the structural performance of steel fibre-reinforced concrete (SFRC) filled steel tubes exposed to ambient and elevated temperatures. For this purpose, fourteen CFST columns were investigated and separated into two groups. The first group of CFST columns was filled with three diverse grades of conventional concrete with and without fibres, which was subjected to ambient temperature. The second group is identical to the first group except all columns are exposed to a temperature of 1050 ℃. The parameters examined were the mechanical properties of concrete, load-carrying capacity, load-deflection response, axial load, and axial strain and ductility ratio. Furthermore, using different codes, a comparison was made for the column's empirically determined load-carrying capacity with the theoretical value. Besides, the morphological characteristics of concrete were examined using energy dispersive spectroscopy (EDS), scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD). The findings show that the SFRC-filled column has superior structural qualities when subjected to elevated temperatures. At high temperatures, calcium hydroxide decomposes, and the steel tube yields, causing the column to fail by premature local bucking.

This article presents the results of numerical simulations performed using ABAQUS/CAE version 2019. The study aims to evaluate the structural integrity of reinforced concrete (RC) T-beams strengthened with externally bonded carbon fiber reinforcements polymer composite materials (EB) (CFRP), especially their response to bending and shear forces. The numerical model was validated by comparing the numerical and experimental results of eight RC T-beams. The numerical analysis was then extended to include various factors, including the impact of the tilt angle of the U-CFRP shell on the shear strength. The goal of this numerical extension is to implement a numerical model capable of simulating the nonlinear behavior of these beams accurately. A comparative analysis is also performed on the experimental and computational models, focusing on the damage modes and their load-induced deformation characteristics. The results showed a satisfactory level of agreement between the two sides. The average ratio of ultimate load to deflection in the numerical model simulation and experimental beam test is 1.004 and 1.046, respectively. The main finding is that inclined U-CFRP deformed at a 45° angle exhibits greater shear stiffness than beams embedded with vertical CFRP panels at a 90° angle, maintaining a constant CFRP panel spacing.