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We present a novel formalism to characterize elastic heterogeneities in amorphous solids. In particular, we derive high-order strain-energy expansions for pairwise energies under athermal quasistatic dynamics. We then use the presented formalism to study the statistical properties of pairwise expansion coefficients and their link with the statistics of soft, quasilocalized modes, for a wide range of formation histories in both two- and three-dimensional systems. We further exploit the presented framework to access local yield stress maps by performing a non-linear stress–strain expansion within a cavity embedded in a frozen matrix. We show that our "bond micromechanics" compare well with the original "frozen matrix" method, with the caveat of overestimating large stress activations. We additionally show how local yield rules can be used as an input for a scalar elasto-plastic model (EPM) to predict the stress response of materials ranging from ductile to brittle. Finally, we highlight some of the limits of simple mesoscale models in capturing the aging dynamics of post-yielding systems. Intriguingly, we observe subdiffusive and diffusive shear band growths for particle-based simulations and EPMs, respectively. [ABSTRACT FROM AUTHOR]

An adjoint‐based procedure to determine weaknesses, or, more generally, the material properties of structures is developed and tested. Given a series of load cases and corresponding displacement/strain measurements, the material properties are obtained by minimizing the weighted differences between the measured and computed values. The present paper proposes and tests techniques to minimize the number of load cases and sensors. Several examples show the viability, accuracy and efficiency of the proposed methodology and its potential use for high fidelity digital twins. [ABSTRACT FROM AUTHOR]

Paper-based materials are being alternative candidates to build load-bearing components for the high demanding building sector to be committed to the green transition, but more knowledge of structural mechanics of such components is needed. In this work, three categories of innovative load-bearing sandwich beams with cup-box core fully made of different paper materials were produced, tested and analyzed in four-point bending. The first failure mode was observed at the top facesheets due to the low compressive strength of paper materials; Beams with thin facesheets had premature buckling failure, whereas those with thicker facesheets exhibited ductility reaching higher deflection before the compressive failure. The developed finite element model, calibrated with the experiments for the equivalent bending and shear rigidities, provided figures of the modulus of the facesheet as well as the properties of the core. Furthermore, the compressive plasticity behavior of the facesheets was assessed by fitting the model with load-deflection curves from the tests. Using the model for the structural optimization of the thickness and height of the core, the work suggests optimal values 3 times higher than the original ones. [ABSTRACT FROM AUTHOR]

The rapidly growing applications of additive manufacturing (AM) are transforming the scenario of the medical industry for sustainably availing customized orthotic products. The adaptive interlinking attribute of 3D printing enables it to replicate the optimization results of a trauma-based anatomical problem, designed and solved with artificial intelligence (AI) for structural mechanics. In the present hybrid approach, the potential of simulation engineering has been used to solve the physics of a mallet trauma transforming existing geometry into an efficacious splint design capable of delivering improved recovery outcomes. The physical measurements have been precisely converted into a customized orthosis, by executing 3D scanning and printing over the optimized parameters availed by data analysis coupled with artificial intelligence of statistical tools. The topological simulation-predicted design was processed for creating the tailored 3D printed mallet splint with a prediction accuracy of 98.49%, availing 42.6% (weight 2.87 gm for 58.28% mass splint) lighter orthosis than the original (weight 5 gm for 100% mass splint) that provides effective ventilation with 149.19% greater heat dissipation. The noninvasive interaction for anthropometric data collection and appealing custom appliances fabricated with bio-sourced materials can trigger faster psychological and physiological healing in patients. The results recorded with an implemented hybrid approach can change the perspective of medical professionals for adopting the AM fused with simulation engineering, as a sustainable alternative to traditional services. The biocompatibility of 3D printed orthotic products facilitates the removal of the excess burden of medical waste and thus the applications of the adopted approach can be practiced for providing sustainable responses to other medical branches like podiatry, dentistry, orthopedics, rheumatology and neuropathy. [ABSTRACT FROM AUTHOR]

The bridge inspection process has multiple steps. One obvious element is for inspectors to identify defects in the main components of the structural system and assign condition ratings. These condition ratings are somewhat subjective because they are influenced by the experience of the inspector. In the current work, processes were developed for making inferences on the reliability of prestressed concrete (PC) girders with defects at the girder component level. The Bayesian network (BN) tools constructed in this study use simple structural mechanics to model the capacity of girders. Expert opinion is used to link defects that can be observed during inspections to underlying deterioration mechanisms. By linking these deterioration mechanisms with changes in mechanical properties, inferences on the reliability of a bridge can be made based on visual observation of defects. The BN can then be used to directly determine the rating factor (RF) of individual structural elements. Examples are provided using BNs to evaluate an existing older PC bridge currently behaving as two simply supported spans. The bridge is modeled using two scenarios with the spans acting as simply supported, and then also with the link block (continuity joint) repaired so that the spans are continuous for live load. The spans are considered simply supported for all dead load. [ABSTRACT FROM AUTHOR]

Non-contact and full-field strain mapping captures strain across an entire surface, providing a complete two-dimensional (2D) strain distribution without attachment to sensors. It is an essential technique with wide-ranging applications across various industries, significantly contributing to experimental mechanics and structural health monitoring. Although there have been reviews that focus on specific methods, such as interferometric techniques or carbon nanotube-based strain sensors, a comprehensive comparison that evaluates these diverse methods together is lacking. This paper addresses this gap by focusing on strain mapping techniques specifically used in experimental mechanics and structural health monitoring. The fundamental principles of each method are illustrated with specific applications. Their performance characteristics are compared and analyzed to highlight strengths and limitations. The review concludes by discussing future challenges in strain mapping, providing insights into potential advancements and developments in this critical field. [ABSTRACT FROM AUTHOR]

Background: Hemodynamics during the growth process of cerebral aneurysms are incompletely understood. We developed a novel fluid–structure interaction analysis method for the identification of relevant scenarios of aneurysm onset. Method: This method integrates both fluid dynamics and structural mechanics, as well as their mutual interaction, for a comprehensive analysis. Patients with a single unruptured cerebral aneurysm were included. Results: Overall, three scenarios were identified. In scenario A, wall shear stress (WSS) was low, and the oscillatory shear index (OSI) was high in large areas within the region of aneurysm onset (RAO). In scenario B, the quantities indicated a reversed behavior, where WSS was high and OSI was low. In the last scenario C, a behavior in-between was found, with scenarios A and B coexisting simultaneously in the RAO. Structural mechanics demonstrated a similar but independent trend. Further, we analyzed the change in hemodynamics between the onset and a fully developed aneurysm. While scenarios A and C remained unchanged during aneurysm growth, 47% of aneurysms in scenario B changed into scenario A and 20% into scenario C. Conclusions: In conclusion, these findings suggest that WSS and the OSI are reciprocally regulated, and both low and high WSS/OSI conditions can lead to aneurysm onset. [ABSTRACT FROM AUTHOR]

To explore the influence of applied materials on the compressive properties of honeycomb structures fabricated by selective laser melting (SLM) technology, four typical materials, titanium alloy (TC11), tool steel (18Ni300), superalloy (GH4169) and aluminum alloy (AlSi10Mg), were selected as raw materials. Composition analysis, surface and internal structure observation, and compression experiments were carried out on the honeycomb structure samples made of four kinds of materials. For experimental analysis, it was found that deformation and cracking are the main compression failure modes. In addition, the compression failure or deformation is located at the middle of the honeycomb structure. Specifically, TC11 material has the strongest resistance to compressive loads, but can withstand small deformations. The comprehensive performance of 18Ni300 and GH4169 are at an intermediate level, which means they have the high resistance to compression and deformation at the same time. AlSi10Mg has the worst performance and is not suitable for use in compressive conditions. This study reveals the compressive mechanical performance of honeycomb structures manufactured with additives, providing experimental support for the functional application of honeycomb structures. [ABSTRACT FROM AUTHOR]

Current strategies for autologous chondrocyte implantation explore the use of gel systems that have structural similarity to an extracellular matrix of cartilage tissue and can act as chondrocyte carriers. However, the major requirement is to address the challenge of maintaining the phenotype and bio-functionality of chondrocytes which often undergo dedifferentiation on expansion, and the appropriate mechanical properties of the matrix that can influence cell attachment and growth. Injectable gel systems are developed in this study by blending different ratios of methacrylated chitosan and polyethylene glycol diacrylate, and photocross-linking the system to attain a stable gel. We hypothesize a multiscale approach of evaluating various parameters like the physical and structural properties of the gel, its wettability and surface free energy and mechano-rheological properties along with the biological characterization (viability assay, collagen, and glycosaminoglycan estimation by immunostaining, biochemical analysis, and RT-PCR assay) of the gel in ascertaining its ideal matrix system. The study provides a correlation between the different parameters to arrive at the most optimum characteristic of an ideal gel system which is dependent not only on the elastic modulus and surface free energy properties of the matrix but also on the composition of the matrix and the phenotype and functionality of the encapsulated chondrocytes. [ABSTRACT FROM AUTHOR]

Externally applied stress on the rock matrix plays a crucial role in oil recovery from naturally fractured tight reservoirs, as local variations in pore pressure and in-situ tension are expected. The published literature severely lacks in evaluations of the characteristics of hydrocarbons, displaced by water, in fractured reservoirs under the action of externally applied stress. This study intends to overcome this knowledge gap by resolving complex time- and stress-dependent multiphase flow by employing a coupled Finite Element Method (FEM) and Computational Fluid Dynamics (CFD) solver. Extensive three-dimensional numerical investigations have been carried out to estimate the effects of externally applied stress on the multiphase flow characteristics at the fracture–matrix interface by adding a viscous loss term to the momentum conservation equations. The well-validated numerical predictions show that as the stress loading increases, the porosity and permeability of the rock matrix and capillary pressure at the fracture–matrix interface decrease. Specifically, matrix porosity decreases by 0.13% and permeability reduces by 1.3% as stress increases 1.5-fold. Additionally, stress loading causes a decrease in fracture permeability by up to 29%. The fracture–matrix interface becomes more water-soaked as the stress loading on the rock matrix increases, and thus, the relative permeability curves shift to the right. [ABSTRACT FROM AUTHOR]

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

Pulmonary valve replacement (PVR) consists of substituting a patient's original valve with a prosthetic one, primarily addressing pulmonary valve insufficiency, which is crucially relevant in Tetralogy of Fallot repairment. While extensive clinical and computational literature on aortic and mitral valve replacements is available, PVR's post‐procedural haemodynamics in the pulmonary artery and the impact of prosthetic valve dynamics remain significantly understudied. Addressing this gap, we introduce a reduced Fluid–Structure Interaction (rFSI) model, applied for the first time to the pulmonary valve. This model couples a three‐dimensional computational representation of pulmonary artery haemodynamics with a one‐degree‐of‐freedom model to account for valve structural mechanics. Through this approach, we analyse patient‐specific haemodynamics pre and post PVR. Patient‐specific geometries, reconstructed from CT scans, are virtually equipped with a template valve geometry. Boundary conditions for the model are established using a lumped‐parameter model, fine‐tuned based on clinical patient data. Our model accurately reproduces patient‐specific haemodynamic changes across different scenarios: pre‐PVR, six months post‐PVR, and a follow‐up condition after a decade. It effectively demonstrates the impact of valve implantation on sustaining the diastolic pressure gradient across the valve. The numerical results indicate that our valve model is able to reproduce overall physiological and/or pathological conditions, as preliminary assessed on two different patients. This promising approach provides insights into post‐PVR haemodynamics and prosthetic valve effects, shedding light on potential implications for patient‐specific outcomes. [ABSTRACT FROM AUTHOR]

The simulation of thermal–fluid–solid coupling in turbines is critically important for design optimization. Historically, most research on thermal–fluid–solid coupling has been conducted in three-dimensional, often with computational speeds that do not meet practical expectations. This study proposes a one-dimensional performance prediction and multi-objective optimization design methodology for turbines, integrating aerothermodynamics and structural strength, to facilitate rapid multidisciplinary coupling design optimization at a low-dimensional level. Initially, a multidisciplinary coupled turbine performance prediction model is established, incorporating the combined effects of turbine aerothermodynamics and structural mechanics. This model links the thermodynamics of the blade passage with the stress and strain of the blade. The predictive accuracy of this model is validated against experimental data from a four-stage axial flow turbine, showing a maximum error of 1.56% for the total temperature ratio and 1.69% for the total expansion ratio. Subsequently, using blade parameters, degree of reaction, load coefficient, and flow coefficient as optimization variables and targeting the turbine's overall isentropic efficiency and power as optimization objectives, a rapid Non-dominated Sorting Genetic Algorithm II and the Technique for Order Preference by Similarity to an Ideal Solution are employed to optimize the last stage of the four-stage axial flow turbine. The optimized turbine demonstrates an increase in overall isentropic efficiency by 1.333% and an increase in overall power by 3.329%, while satisfying structural strength requirements. The novelty of this study lies in its rapid optimization design and performance prediction method for the coupled aerothermodynamics and structural mechanics at a one-dimensional level. [ABSTRACT FROM AUTHOR]

The operation of wind turbines involves a complex interaction between aerodynamics, structural mechanics, and control systems. However, the control system is frequently overlooked. To investigate the impact of the control system on the aerodynamic characteristics and elastic deformations of wind turbines, this paper initially integrates the control system into the blade element momentum theory (BEMT) for calculating aerodynamic forces. Subsequently, the control system is incorporated into fluid-structure interaction (FSI) calculations to assess its influence on the overall performance of the turbine. The control system employs variable speed and pitch control, while the structural dynamics are modeled using the Euler-Bernoulli beam theory. When the control system is integrated with blade element momentum theory to calculate the aerodynamic forces of the wind rotor, it is observed that, below the rated wind speed, a portion of the torque error is transferred to the rotor speed. In contrast, above the rated wind speed, the entire torque error is transferred to the blade pitch angle (BPA). Crucially, when the control system is integrated, the rotor speed and BPA are no longer treated as known parameters. This approach enables the prediction of aerodynamic characteristics of the wind rotor, particularly under complex wind speed profiles. The control system exerts a significant influence on the FSI results, particularly in the range of wind speeds that correspond to larger blade deformations. This work can provide a reference for the calculation of aerodynamic characteristics and FSI of wind turbines under complex wind conditions. [ABSTRACT FROM AUTHOR]

When the coal mining face enters the final stage of mining, the roadway faces the superimposed influence of surrounding rock stress redistribution and roof rotary moment. As affected by the strong disturbance in the coal mining process, the roof plate of the roadway has undergone serious deformation, which seriously affects the stability of the roadway. Taking the 108 working face of the Jinjitan coal mine as the engineering background, a comprehensive study was conducted on the control of the perimeter rock in the retracement of a tunnel in a heavy coal seam with a large mining height. By analyzing the physical properties of the enclosing rock of the retreated roadway, and using theoretical analysis, numerical simulation, on-site monitoring, and other methods, the characteristics of the peripheral rock's movement relationship and mineral pressure manifestation in the final mining stage of the large-height working face have been studied. The structural mechanics model was established, and in the case where the support cannot be solved just by strengthening the support, the design scheme of "blasting roof break + constant resistance anchor cable support" was innovatively tried. FLAC3D simulation results show that the stress release of the surrounding rock is more adequate when the height of roof cutting is 20 m. The stress of the surrounding rock near the roadway is reduced by 30~40%, and the stress state is reasonable. The constant resistance and large deformation anchors can absorb the deformation energy of the rock body, maintain constant working resistance and stable deformation, and have good rock stability control, which is conducive to the stability of the roadway. [ABSTRACT FROM AUTHOR]

Autonomous underwater helicopters (AUHs) are complex electromechanical systems consisting of multiple interconnected sub-disciplines, posing a significant challenge for traditional sequential design strategies in managing their interactions. To address this challenge, a multidisciplinary collaborative optimization (MCO) strategy is proposed, integrating structural, hydrodynamic, and energy disciplines to enhance AUH cruising range. Additionally, a novel approximation model is introduced, combining the Logistic-Tent chaos sparrow search algorithm (LTC-SSA) with the back-propagation neural network (BPNN) algorithm. This method aims to replace costly computational fluid dynamics (CFD) and structural mechanics calculations, thus reducing AUH optimization costs. The laminate design of the composite pressure hull follows classic lamination theory (CLT) and the Tsai-Wu failure criterion. Results demonstrate that the multidisciplinary co-design strategy significantly reduces optimization time costs of AUH, from several months to several days. Furthermore, the proposed LTC-SSA-BPNN algorithm accurately evaluates sailing resistance and Tsai-Wu failure index, with maximum errors of 1.64% and 9.32% respectively. Additionally, the composite pressure shell achieves a 30.4% weight reduction and a 4.1% reduction in sailing resistance while maintaining structural stability. Moreover, the maximum cruising range increases by 34.4%. This strategy offers theoretical support for AUH conceptual design and promises performance enhancement in practical engineering applications. [ABSTRACT FROM AUTHOR]

This article explores the intricate relationship between plant structure and stability, shedding light on the fundamental aspects that enable plants to withstand environmental forces and maintain an upright position. Delving into the realms of geotechnical biology, we dissect the genetic, environmental, and biological influences shaping plant structures. From the physical perspective, we examine how plant structures facilitate water absorption, nutrient transport, and resistance to environmental stress. Emphasizing the crucial role of root systems in anchoring and providing stability, we navigate through the evolutionary adaptations of different plant structures in response to varying environmental conditions. The concept of stability is elucidated, encompassing factors such as root structure, stem strength, flexibility, and biomass distribution. The influence of growth environment, including soil composition and moisture levels, on plant stability is highlighted, alongside the importance of external factors like wind, rain, and animal activities. The article concludes by emphasizing the need for a multidisciplinary approach, involving insights from plant biology, geotechnical engineering, and structural mechanics, to enhance the stability and resilience of plant structures. [ABSTRACT FROM AUTHOR]

We present an isogeometric analysis (IGA) framework for structural vibrations involving complex geometries. The framework is based on the Complex-Geometry IGA Mesh Generation (CGIMG) method. The CGIMG process is flexible and can accommodate, without a major effort, challenging complex-geometry applications in computational mechanics. To demonstrate how the new IGA framework significantly increases the computational effectiveness, in a set of structural-vibration test computations, we compare the accuracies attained by the IGA and finite element (FE) method as the number of degrees-of-freedom is increased. The results show that the NURBS meshes lead to faster convergence and higher accuracy compared to both linear and quadratic FE meshes. The clearly defined IGA mesh generation process and significant per-degree-of-freedom accuracy advantages of IGA over FE discretization make IGA more accessible, reliable, and attractive in applications of both academic and industrial interest. We note that the accuracy of a structural mechanics discretization, which may be assessed through eigenfrequency analysis, plays an important role in the overall accuracy of fluid–structure interaction computations. [ABSTRACT FROM AUTHOR]

The development of the open-pit mining industry has set higher performance standards for mining electric shovels. Addressing issues such as low efficiency, high energy consumption, and high failure rates in working mining electric shovel devices, this paper comprehensively considers bulk mechanics, structural mechanics, and dynamics to conduct a multidisciplinary, collaborative design optimization for electric shovels by introducing the BLISCO method, which is based on an approximated model, into the structural-optimization design process of working electric shovel devices, aiming to enhance the overall performance of electric shovels. Firstly, a dynamic model of an electric shovel is established to analyze the hoist force and crowd force during the excavation process, and an accurate load input for the dynamic analysis is provided through the bulk material mechanics model. Additionally, to ensure that the stiffness of the boom meets the requirements, the maximum stress at the most critical position of the optimized boom is considered. Subsequently, the design variables are screened through experimental design, and an approximate model is established. Focusing on the hoist force, crowd force, maximum stress at the critical position of the boom, and the angle between the dipper arm and the wire rope, a mathematical model is constructed and optimized using a two-level integrated system co-optimization framework based on an approximate model (BLISCO-AM), followed by a simulation. Finally, a test bench for the electric shovel working device is constructed to compare pre- and post-optimization performance. Experimental results show that through the optimized design, the hoist force and crowd force required in a single excavation process are reduced by 6% and 8.48%, respectively, and the maximum angle between the wire rope and the dipper arm is increased by 4%, significantly improving excavation efficiency while ensuring the safety and reliability of the equipment. [ABSTRACT FROM AUTHOR]

The aim of this research article is to share a study conducted within the epistemological phase of mathematical theory in the context of the sciences. This study, developed by Patricia Camarena Gallardo, involves the development, presentation, and analysis of a didactic intervention aimed at revisiting the study of functions in an introductory course on differential and integral calculus. This approach is based on a contextualized problem in civil engineering, specifically a situation related to the dynamic analysis of a frame. The development of the intervention, with an expected duration of 12 hours per class, was methodologically supported by the analysis of a textbook on structural mechanics, as well as two calculus textbooks. Additionally, the study considered the curriculaof calculus courses, topics related to the historical development of the notion of function, the epistemological obstacles encountered in this process, as well as cognitive issues related to it. [ABSTRACT FROM AUTHOR]

Micro elastofluidics is a transformative branch of microfluidics, leveraging the fluid–structure interaction (FSI) at the microscale to enhance the functionality and efficiency of various microdevices. This review paper elucidates the critical role of advanced computational FSI methods in the field of micro elastofluidics. By focusing on the interplay between fluid mechanics and structural responses, these computational methods facilitate the intricate design and optimisation of microdevices such as microvalves, micropumps, and micromixers, which rely on the precise control of fluidic and structural dynamics. In addition, these computational tools extend to the development of biomedical devices, enabling precise particle manipulation and enhancing therapeutic outcomes in cardiovascular applications. Furthermore, this paper addresses the current challenges in computational FSI and highlights the necessity for further development of tools to tackle complex, time-dependent models under microfluidic environments and varying conditions. Our review highlights the expanding potential of FSI in micro elastofluidics, offering a roadmap for future research and development in this promising area. [ABSTRACT FROM AUTHOR]

Lapped column transition is a novel structural form. In lapped column transition structures, the reinforcement at the lapped column nodes is generally dense, which is highly unfavorable for construction operations. Even if construction operations are carried out, it is difficult to guarantee the construction quality and mechanical performance of the nodes. To address this issue, taking a practical engineering project as an example, a comprehensive optimization of the reinforcement layout in lapped columns is conducted using BIM (Building Information Modeling) and FEM (Finite Element Method) technologies. The research results demonstrate that BIM technology can effectively and rapidly optimize the reinforcement layout in lapped columns, resulting in a layout that is more conducive to on-site construction and can effectively ensure construction quality. FEM technology can effectively perform mechanical performance calculations on the optimized lapped columns, with the mechanical performance of the optimized lapped columns being basically unchanged and still meeting the requirements of engineering structural mechanics. [ABSTRACT FROM AUTHOR]

In multi-seam mining, as mining ranges expand and depths increase, the strong ground pressure exerted on the lower coal-seam working faces (WFs) or roadways by coal pillars (CPs) and the hard roof between the interburdens becomes increasingly severe, leading to periodic roof-fall accidents. This study focused on the 42108 WF of the 4-2 coal seam in the Buertai Coal Mine of Shandong mining. It combined field tests, theoretical research, and numerical calculations to investigate the superposition or amplification of ground pressure as WF traversed the CP with the hard roof between interburdens. The ground pressure behavior of WF entering and exiting the CP stage progressed from strong to weak: exiting the CP > under the CP > entering the CP, with the CP stage being prone to a strong ground pressure occurrence. We proposed the influence mechanism of strong ground pressure and a seesaw structural mechanics model under the mining conditions with parallel CPs and hard roofs. The relationship between the geometric structure movement and stress evolution of the seesaw space of the overlying hard roof was analyzed, revealing the mechanism behind stress increase, evident damage, and the likelihood of dynamic disasters within 5-10 m from the CP boundary of the WF. The stress concentration factor (SCF) of the advance abutment pressure in the coal wall was the primary controlling factor determining seesaw instability, effectively ensuring safe and efficient mining practices. This research holds significant theoretical importance and practical engineering value for controlling strong mine pressure under the overlying CPs and hard roofs. [ABSTRACT FROM AUTHOR]

The method of numerical-analytical modeling using Maple 18 of the strong buckling of a uniform console with a symmetrical cross-section is presented. The range of plastic deformations in a materials with conditional yield strength (CYS) is studied. Standard profiles and sections made of low-carbon steel, titanium, polyethylene etc. were investigated. Were found and compared with the proper Eulerian values the critical loads of Fcr, N, the shape of buckled console y(z). The quasi-identity of the latter is established for the same slope pf = dy/dz near the free console end. The method can be applied in robotics, structural mechanics, medical prosthetics, etc. where the materials been used with relatively high Young's modulus and low the CYS. [ABSTRACT FROM AUTHOR]

The evolution of long-span timber structures during the last centuries has been driven by technological developments that are associated with materials, joints, and manufacturing. Many extraordinary structural solutions have been developed, some of which have been very advanced in their time and have been replaced by new ones, typically because of the advent of new manufacturing methods or, at times, due to new technological innovations. This study examines the Hilding Brosenius (HB) system, which was developed in the 1940s as a versatile wooden frame solution for medium-to-long spans. The HB system is based on an I-shaped cross section where the web consists of two diagonal board layers, and the flanges are assembled from boards by nailing and gluing. This study presents and discusses the main structural components of the system from the perspective of structural mechanics, current design requirements, and manufacturing technologies. As a practical application example, the structural system will be examined in the renovation project of an HB portal frame from the 1950s. The main findings of this study are: (1) the HB system has certain features that would make it worthwhile modernizing and reusing it more widely; and (2) the HB system design principles lead to a safe and robust yet light and optimal structure. [ABSTRACT FROM AUTHOR]

This paper highlights the development and validation of two innovative modular cantilever (MC) designs for railway overhead applications. Existing MCs are heavy, complex, and prone to failures. Addressing these shortcomings, the proposed designs leverage topology optimization and TRIZ principles to achieve significant improvements: weight reduction: Up to 28% lighter than existing MCs due to optimized material distribution. Enhanced robustness: Improved structural efficiency and strength, reducing failure risk. Simplified assembly and maintenance: fewer components and modular design facilitate easier handling and installation. Environmental resistance: increased durability against fatigue cracking, corrosion, and wear and tear. Numerical calculations and finite element analysis validate the performance of the new designs, confirming their ability to withstand dynamic loading conditions equivalent to traditional MCs. These lightweight, robust, and adaptable solutions offer tremendous potential for reducing costs, improving safety, and optimizing performance in railway overhead applications. [ABSTRACT FROM AUTHOR]

The reliable exchange of data is a crucial issue for the loose coupling of computational fluid dynamics (CFD) and computational structural mechanics (CSM) modules in fluid–structure interaction (FSI) applications. This paper presents a comparison between two methods for mapping the traction field across mismatching grids, namely the RIBES method and the preCICE algorithm, both based on radial basis function (RBF) interpolation. The two methods demonstrate different degrees of control over balance preservation during mapping, with the RIBES algorithm exhibiting greater efficacy. Test benches are a parametric double curved geometry and a wind tunnel mock-up. In this second case, forces from mapping are used to load a CSM model to retrieve stress and displacement fields. Differences in FEM results are appreciable although not significant, showing a correlation between the accuracy of balance preservation during data mapping and the structural output. [ABSTRACT FROM AUTHOR]

This paper presents a computational procedure for the determination of the dynamic behaviour of graphene with different types of defects. The lattice of graphene is modelled using the molecular structural mechanics (MSM) approach, where the C–C covalent bonds are replaced by equivalent beam elements. Cantilever and bridged boundary conditions are applied for the analysis. Four types of Stone–Wales (SW) defects such as S-W (555-8), S-W (555-888-3), S-W (555-77-8) and S-W (888-3), and two types of pinhole defects with 6 and 24 elements eliminated are examined on armchair, zigzag and chiral type of graphene sheet. The effect of the structural length of the sheet, chirality and defect type on the vibrational properties of graphene sheets is investigated. The computed results reveal that SW defects produce a high frequency to that of pristine graphene, whereas the effect of pinhole defects is significant as compared to SW defects. The computed results will be useful in nano-resonator-based sensor applications. [ABSTRACT FROM AUTHOR]

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Topology optimization is one of the most flexible structural optimization methodologies. However, in exchange for its high level of design freedom, typical topology optimization cannot avoid multimodality, where multiple local optima exist. This study focuses on developing a gradient-free topology optimization framework to avoid being trapped in undesirable local optima. Its core is a data-driven multifidelity topology design (MFTD) method, in which the design candidates generated by solving low-fidelity topology optimization problems are updated through a deep generative model and high-fidelity evaluation. As its key component, the deep generative model compresses the original data into a low-dimensional manifold, i.e., the latent space, and randomly arranges new design candidates over the space. Although the original framework is gradient free, its randomness may lead to convergence variability and premature convergence. Inspired by a popular crossover operation of evolutionary algorithms (EAs), this study merges the data-driven MFTD framework and proposes a new crossover operation called latent crossover. We apply the proposed method to a maximum stress minimization problem in 2D structural mechanics. The results demonstrate that the latent crossover improves convergence stability compared to the original data-driven MFTD method. Furthermore, the optimized designs exhibit performance comparable to or better than that in conventional gradient-based topology optimization using the P-norm measure. [ABSTRACT FROM AUTHOR]

The upper frozen layer is one of the main factors affecting the blasting effect of the plateau open-pit bench. To clarify the fracture law of the upper frozen layer of the open-pit bench under the blasting load in the cold area of the plateau, this paper uses the particle flow code method to simulate the fracture process of the natural single frozen layer and the artificial composite double-frozen layer under the action of single and double rows of blast holes respectively. The frozen layer s speed, impact pressure, and fragmentation characteristics were analyzed. The results show that the frozen layer undergoes the failure process of cracking-local uplift-macro fracture. For the artificial composite frozen layer,the thickness increases due to the increase of the gravel soil in the upper part, which weakens the overall uplift trend of the frozen layer and leads to increased fragmentation. The impact pressure on the frozen layer in the middle of the double-row blast hole first reaches the peak, but the peak value on the frozen layer near the free surface is higher. The fracture problem of single and double frozen layers under blasting load can be simplified as the structural fracture mechanics problem under impact pressure. The large block rate of double-frozen-layer bench is 4% to 6% higher than that of single-frozen-layer. It is suggested that in the blasting of plateau open-pit mines, the area that needs special treatment should be preliminarily determined by the thickness of the frozen layer, and the large block rate should be reduced by adjusting the delay time to improve the efficiency of shovel-to-digging. [ABSTRACT FROM AUTHOR]

This paper presents an innovative self-centering dual-limb thin-walled rocking pier with replaceable energy dissipation beams (DLTW-REDB), combining selfcentering hybrid system concepts with DLTW bridge piers. It addresses the issue of DLTWpiers being prone to damage in the longitudinal direction during strong earthquakes, enabling rapid post-earthquake recovery. The study focuses on the following aspects: (1) A 1:5 scale quasistatic reversed cyclic test was conducted to assess the seismic performance of the system. The results demonstrated that the hybrid system exhibited a characteristic "flag-shaped" hysteretic response, similar to traditional rocking bridge piers. It exhibited excellent energy dissipation and self-centering capability.Moreover, plastic damage primarily occurred in the replaceable energy dissipation beam, which could be easily replaced within 2 h while restoring the original structural behavior. (2) The self-centering mechanism of the system was analyzed based on principles of structural mechanics, explicitly deriving the hysteresis, and residual deformation expressions. A quantitative index, the self-centering coefficient (λ), was established to measure the self-centering capability. (3) Numerical models were employed to analyze the sensitivity of parameters such as the prestressed reinforcement ratio, initial tension in prestressing tendons, and yield force of the energy dissipation beam. The results suggested that raising the initial tension enhanced the bearing force and reduced the residual displacement. However, raising the yield force improved the bearing capacity and energy dissipation capability, while residual displacement increased. Therefore, it is recommended to set the self-centering coefficient at approximately 1.0 to achieve a trade-off between effective energy dissipation capacity and acceptable residual deformation. [ABSTRACT FROM AUTHOR]

Data-driven models utilizing powerful artificial intelligence (AI) algorithms have been implemented over the past two decades in different fields of simulation-based engineering science. Most numerical procedures involve processing data sets developed from physical or numerical experiments to create closed-form formulae to predict the corresponding systems' mechanical response. Efficient AI methodologies that will allow the development and use of accurate predictive models for solving computational intensive engineering problems remain an open issue. In this research work, high-performance machine learning (ML) algorithms are proposed for modeling structural mechanics-related problems, which are implemented in parallel and distributed computing environments to address extremely computationally demanding problems. Four machine learning algorithms are proposed in this work and their performance is investigated in three different structural engineering problems. According to the parametric investigation of the prediction accuracy, the extreme gradient boosting with extended hyper-parameter optimization (XGBoost-HYT-CV) was found to be more efficient regarding the generalization errors deriving a 4.54% residual error for all test cases considered. Furthermore, a comprehensive statistical analysis of the residual errors and a sensitivity analysis of the predictors concerning the target variable are reported. Overall, the proposed models were found to outperform the existing ML methods, where in one case the residual error was decreased by 3-fold. Furthermore, the proposed algorithms demonstrated the generic characteristic of the proposed ML framework for structural mechanics problems. [ABSTRACT FROM AUTHOR]

When braided dense-mesh stents are used to treat carotid stenosis, the structural mechanics of vascular stents, the contact mechanics with blood vessels, and the fluid mechanics in the blood environment need to be studied in depth to reduce the damage of stents to blood vessels and the incidence of in-stent restenosis. Three types of braided stents with 8, 16, and 24 strands and laser-cut stents with the corresponding size parameters were designed, and the bending behavior of each of these types of stent, deployment, and fluid dynamic analysis of the 24-strand braided stent were simulated. The results show that the bending stress of the 8-, 16-, and 24-strand braided stents is 46.33%, 50.24%, and 31.86% of that of their laser-cut counterparts. In addition, higher strand density of the braided stents was associated with greater bending stress; after the 24-strand braided stent was expanded within the stented carotid artery, the carotid stenosis rate was reduced from 81.52% to 46.33%. After stent implantation, the maximum stress on the vessel wall in a zero-pressure diastolic environment decreased from 0.34 to 0.20 MPa, the maximum pressure on the intravascular wall surface decreased from 4.89 to 3.98 kPa, the area of high-pressure region decreased, the wall shear force of the stenotic segment throat decreased, and blood flow increased in the stenosis segments. The braided stent had less bending stress and better flexibility than the laser-cut stent under the same stent size parameters; after the 24-strand braided stent was implanted into the stented vessel, it could effectively dilate the vessel, and the blood flow status was improved. [ABSTRACT FROM AUTHOR]

This paper presents a fully coupled solution in the time-domain, using the finite-differences method to the system of equations that model the dynamic behavior of the riser, blow-out preventer (BOP), and casing strings, when connected for well drilling/completion--the model is suitable to evaluate wellhead fatigue, even when the amplitude of oscillation and accelerations of the BOP are high. Sensibility analysis is used to show the effect of changing the Riser Top Tension to the resulting maximum values of wellhead bending moment and casing stress ranges. For the case where the rig is oscillating around a fixed position and there is no current, using a regular wave, the results show that there are some wave periods for which an increase in the Riser Top Tension reduces the maximum wellhead bending moment and the max casing stress range, therefore increasing fatigue life of the casing and wellhead. The effects of varying the weight of the BOP and soil parameters and the effect of the phase difference between the wave and first-order vessel motion are analyzed. The proposed solution can also be used to perform riser and casing analysis during drift-off/drive-off. [ABSTRACT FROM AUTHOR]

The formation of suitable cycle bases corresponding to sparse flexibility matrices for the force method of frame analysis has always been an interesting problem in structural mechanics. These cycle bases are needed for the formation of static bases for efficient force method of structural analysis. Similarly, such bases are required in the mesh analysis of other networks. This paper reviews methods for the cycle basis selection by utilizing different embeddings on higher dimensional topological spaces, and using the ideas and concept from this study, graph theory algorithms are developed for efficient computational algorithms for the formation of subminimal, and minimal cycle bases. [ABSTRACT FROM AUTHOR]

Mechanical interfaces are prevalent in industries like aerospace and maritime, where the normal contact stiffness on these surfaces is a crucial component of the overall stiffness of mechanical structures. From the perspective of structural mechanics, normal contact stiffness significantly affects the dynamic response of mechanical structures and must be considered in mechanical design and simulation analysis. Essentially, the mechanical interface represents a typical type of nonlinear contact, characterized by both its non-uniform distribution and its frequency-dependent properties under external excitations. A plate structure was designed to study the distribution and frequency-dependent characteristics of normal contact stiffness on the mechanical interface. Experiments validated that the normal contact stiffness not only significantly increases the fundamental frequency of the plate but also alters its mode shapes. To replicate the experimental results in simulations, the BUSH elements were used to model the normal contact stiffness within the plate structure, arranging it non-uniformly and setting it to vary with frequency according to the plate's mode shapes and frequency response. This method accurately replicated the plate's mode shapes and response curves within the 0–1000 Hz range in simulations. [ABSTRACT FROM AUTHOR]

In flapping insect wings, veins support flexible wing membranes such that the wings form feathering and cambering motions passively from large elastic deformations. These motions are essentially important in unsteady aerodynamics of insect flapping flight. Hence, the underlying mechanism of this phenomenon is an important issue in studies on insect flight. Systematic parametric studies on strong coupling between a model wing describing these elastic deformations and the surrounding fluid, which is a direct formulation of this phenomenon, will be effective for solving this issue. The purpose of this study is to develop a robust numerical framework for these systematic parametric studies. The proposed framework consists of two novel numerical methods: (1) A fully parallelized solution method using both algebraic splitting and semi‐implicit scheme for monolithic fluid–structure interaction (FSI) equation systems, which is numerically stable for a wide range of properties such as solid‐to‐fluid mass ratios and large body motions, and large elastic deformations. (2) A structural mechanics model for insect flapping wings using pixel modeling (pixel model wing), which is combined with explicit node‐positioning to reduce computational costs significantly in controlling fluid meshes. The validity of the proposed framework is demonstrated for some benchmark problems and a dynamically scaled model incorporating actual insect data. Finally, from a parametric study for the pixel model wing flapped in fluid with a wide range of solid‐to‐fluid mass ratios, we find a FSI mechanism of feathering and cambering motions in flapping insect wings. [ABSTRACT FROM AUTHOR]

This study aims to review and highlight the important modelling methodologies used for studying carbon nanotubes (CNTs) and their composites. Understanding appropriate modelling methods for specific applications is crucial as CNTs become integral in achieving lighter, multifunctional composite structures. This paper explores a range of techniques, including finite element modelling (FEM), Molecular Dynamics (MD), Molecular Structural Mechanics (MSM), as well as nonlocal models, and the Cauchy-Born (CB) rule. Emphasis is placed on factors such as interphase effects between CNTs and the matrix, bonding interactions, non-bonded van der Waals (vdW) forces, and dynamic behaviour. Multiscale modelling is extensively discussed as a pivotal approach for efficiently addressing various length scales in nanocomposites. Modelling of failure, damage and its propagation, delamination, and instabilities such as buckling and fracture have been highlighted, and research gaps have been pointed out. [ABSTRACT FROM AUTHOR]

The structural optimization of Ti-alloy lattice structure formed by the superplastic forming/diffusion bonding (SPF/DB) process is a high-nonlinear problem with multiple design variables. The problem is solved in this research by introducing the modified Kriging response surface model based on structural mechanics analysis and the genetic algorithm into the optimization design of the Kagome structure. The comprehensive influence of the structural parameters on the shape and compressive strength of the structure is analyzed, and the optimized structural parameters are obtained. The SPF/DB forming and performance test of the optimized Kagome structure are carried out for verifying the accuracy of the model. The results show that the modified Kriging response surface model of the Kagome structure performs well in describing the relationships between the structural parameters and the simulation results, the average relative error of the predicted groove depth and compression strength are 2.4% and 4.5%, respectively. The specific compression strength and the specific compression modulus of the optimized Kagome structure are 5.21 × 10 4 N · m / kg and 1.50 × 10 6 N · m / kg. Based on the compression strength results calculated by the Kriging model, a new Ashby plot for the compressive strength as function of density is obtained. [ABSTRACT FROM AUTHOR]

A computational framework is presented to numerically simulate the effects of antihypertensive drugs, in particular calcium channel blockers, on the mechanical response of arterial walls. A stretch‐dependent smooth muscle model by Uhlmann and Balzani is modified to describe the interaction of pharmacological drugs and the inhibition of smooth muscle activation. The coupled deformation‐diffusion problem is then solved using the finite element software FEDDLib and overlapping Schwarz preconditioners from the Trilinos package FROSch. These preconditioners include highly scalable parallel GDSW (generalized Dryja–Smith–Widlund) and RGDSW (reduced GDSW) preconditioners. Simulation results show the expected increase in the lumen diameter of an idealized artery due to the drug‐induced reduction of smooth muscle contraction, as well as a decrease in the rate of arterial contraction in the presence of calcium channel blockers. Strong and weak parallel scalability of the resulting computational implementation are also analyzed. [ABSTRACT FROM AUTHOR]

The Tyennan Domain of western Tasmania is a structurally emplaced, complexly deformed lithotectonic sheet (allochthon). It comprises stacked, isoclinally folded slabs of allochthonous high-grade schist including garnet schist and quartzite, amphibolite and rare eclogite (uppermost unit), overlying low-grade pelite, overlying low-grade quartzite and platy quartzite (middle unit), overlying parautochthonous low-grade dolomitic pelite, quartzite and dolostone (lowermost unit). It is a product of Cambrian continental margin subduction, rebound and exhumation coupled with ophiolite obduction. Tyennan rocks were transported to maximum depths of ∼60–80 km sufficient to generate high-P metamorphism. Their deformation involved progressive shear, large shear strains and large shear displacements with a bulk west-over-east sense of shear related to the direction of subduction and buoyant exhumation. The Tyennan Domain shows a unique crustal architecture, including: (1) metamorphic sheets with 100 km lengths, 50 km widths and 5–10 km structural thicknesses, (2) a leading edge fold nappe with ∼200 km axial surface trace length, (3) megasheath folds with 20–25 km dimensions, and (4) asymmetric folds within regional scale shear lozenges as macro-augen. It provides an unparalleled window beneath the now, largely eroded, obducted ophiolite sheet and provides structural insight into the mechanics of continental margin subduction–obduction. Deformation has been partitioned through the composite exhumed 'slab' with domains of isoclinal macrofolds transitioning into regional scale sheath folds bounded by zones of higher strain. The higher strain zones are characterised by transposition foliation, rootless mesoscopic isoclinal folds, small-scale sheath folds, overprinting crenulation cleavages and platy mylonitic to schistose zones in quartzite. The uppermost, high-grade part of the Tyennan allochthon is clearly a composite, ∼1 km thick 'sheet' made up of a 'welded' amalgam of largely pelitic fragments that had been subducted to different depths, assembled and deformed during buoyant ascent to the current structural level. The Tyennan Domain represents the subducted part of a microcontinent during a Cambrian arc–microcontinent collision outboard of the eastern Pacific margin of Gondwana. The Tyennan Domain consists of stacked, recumbent and isoclinally folded slabs of allochthonous high-grade schist and low-grade pelite-quartzite, overlying parautochthonous low-grade dolomitic marl, quartzite and dolostone. Isoclinal, asymmetric, macrofold 'wave trains', megasheath folds and a 'leading edge' fold nappe with ∼200 km length scale dominates the structure of the Tyennan Domain. [ABSTRACT FROM AUTHOR]