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Beam exit windows are crucial components of any particle accelerator as they provide an interface between the beamline vacuum and target material at atmospheric media. For high beam power machines, special materials and designs are required to withstand high radiation and mechanical loads, while minimizing energy loss during transition and maximizing window lifetime. This research investigates the impact of electron beam exposure to bulk CrMnV and CrMnTiV high entropy alloys (HEAs) with the primary goal of identifying suitable candidate materials for the design of robust and durable exit window settings. The selection criteria include intrinsic characteristics, power dissipation, and mechanical responses. According to the thermodynamic calculations, both equiatomic CrMnV and the addition of 7% of Ti with equiatomic CrMnV yield solid-solutions phases. The structural and mechanical properties of CrMnV and CrMnTiV samples were tested using field emission scanning electron microscopy, atomic force microscopy, scanning electron microcopy with energy dispersive x-ray spectroscopy, x-ray diffraction, and nanoindentation before and after exposure to a dose of ∼66 kGy from a 10 MeV e-beam accelerator. Despite exhibiting beam transmission characteristics comparable to Cr and V, the indentation hardness of HEAs exceeded that of the Cr and V samples by five to six times. The examination of the CrMnTiV irradiated samples revealed organized deformation patterns depicting new features, which we suspect twinning and twin boundaries due to the addition of Ti to CrMnV. Ti, a hexagonal-close-packed crystal structure, is commonly known for deformation twinning behavior. [ABSTRACT FROM AUTHOR]

Using commercially available components, a compact laboratory-type prototype has been developed and assembled to demonstrate single and multicaloric effects arising from single and cyclic applications of magnetic fields and uniaxial mechanical loads. Using the example of the LaFe11.4Mn0.3Si1.3H1.6 alloy with a first-order phase transition near room temperature, the possibility of observing magnetocaloric, elastocaloric, and multicaloric effects is demonstrated. It is shown that by selecting protocols for applying combined external influences: magnetic field and mechanical load, it is possible to observe a synergistic effect for adiabatic temperature change, which amounts to 1.17 K (0.31 T and 19 MPa) at a temperature of 291.5 K for the multicaloric effect, which exceeds the corresponding value of |ΔT| = 0.75 K (0.31 T) at a temperature of 291.65 K for the magnetocaloric effect. The proposed approaches and obtained results can be used for the development of new prototypes of multicaloric cooling systems and the optimization of current ones. [ABSTRACT FROM AUTHOR]

Epoxy insulators in gas-insulated power apparatus are subjected to the combined effects of electrical and mechanical loads. In this work, a simulation model is built based on the energy theory to explore the electrical tree growth of epoxy resin under tensile and compressive stresses. With increasing AC voltage, the electrical tree growth is promoted, exhibiting a morphology with more branches. Tensile stress accelerates the electrical tree growth, while proper compressive stress has the opposite effect. However, when the compressive stress exceeds a certain value, electrical tree growth is promoted again. When the mechanical stress is vertical to the needle electrode, these effects primarily impact the length of the trees. Conversely, in parallel cases, mechanical stress mainly affects the width of the electrical trees. Filler doping play the role of obstacles as well as enhancing the electric field concentration, the electrical tree growth is firstly inhibited and then promoted as the doping content increases. The electrical tree morphologies of simulation and experiment are in good consistency, proving the reasonability of the simulation model. [ABSTRACT FROM AUTHOR]

Due to the importance of safety in the process of structural designing of the modern buildings' ceiling, this study gravitates on a novel topic of analyzing thermoelastic response of the concrete ceiling reinforced with nanoparticles of graphene-platelets (GPL). To this end, the mentioned ceiling is considered as a fully-clamped rectangular plate exposed to simultaneous impact of thermal and mechanical loads. The exact form of the elasticity theory in conjunction with the differential quadrature method is employed for acquiring the behavior of the system. Then, an artificial intelligence-based method is used to accelerate the computational process. Efficiency and accuracy of the employed solution are examined and verified by means of a comparative study. The results of this article would be broadly employed in the structural design of the modern constructions in the near future. [ABSTRACT FROM AUTHOR]

Purpose: The present paper aims to study the influence of the substrate system on the thermomechanical response of various lead-free die attach materials used in power electronics using nonlinear finite element simulations. Design/methodology/approach: Particularly, three ceramic substrate systems, including direct copper bonded (DCB) and aluminum nitride (AlN) – as well as silicon nitride (Si3N4) –based insulated metal substrate (IMS) configurations are examined in this study. Additionally, three die attach systems, namely, silver-tin transient liquid phase (TLP), sintered silver (Ag) and sintered copper (Cu) are included in the analysis. ANSYS software is employed to build the finite element models of the power modules and to conduct the nonlinear thermomechanical investigations. Findings: The simulation results revealed that the IMS, Si3N4 and DCB-based power modules end up with significantly lower interconnect inelastic strains and inelastic strain energies suggesting better fatigue life performance. Additionally, the bonding layer stresses and expected failure mechanism are not influenced by the substrate configuration rather than the bond material. For instance, the silver-tin TLP joints develop high stresses and hence brittle failures are expected. Nonetheless, the sintered Ag and sintered Cu have significantly lower stresses which could lead to fatigue-induced failures. Originality/value: Power electronics use various ceramic-based substrate systems because of their improved thermal conductivity, electrical insulation and heat resistance properties. The proper selection of the substrate structure could highly enhance the thermal fatigue of the power modules. Markedly, the findings of this research are useful for designing highly reliable and effective power modules continuously subjected to thermomechanical loadings. [ABSTRACT FROM AUTHOR]

Detrended fluctuation analysis (DFA) and sample entropy (SE) measure the long-term correlations and regularity of gait patterns, respectively, having previously been used to identify participants at risk of falling, previous history of injury, or patients with motor diseases. Since these measures are more sensitive to gait impairment than linear measures (e.g., the standard deviation [SD] of stride time), they can be potentially used in military medicine to identify soldiers at risk of injury. However, clinometric properties are yet to be established. What is the repeatability of DFA, SE, and traditional linear measures of stride time variability (SD and coefficient of variation [CV]) under various load and speed constraints? Fourteen Australian Army trainee soldiers (age: 25.6 ± 5.9 y, height: 1.74 ± 0.08 m, body mass: 77.2 ± 15.1 kg, service: 1.5 ± 1.8 y) attended three sessions over two weeks, completing four 12-minute walking trials on an instrumented treadmill in each session. Participants walked with a combination of 0 kg or 23 kg loads at a self-selected or 5.5 km/h speed. Heel contacts from the right foot were identified using treadmill-embedded force plates. From 512 stride time intervals, linear (SD and CV), and non-linear (DFA and SE) measures were obtained. To assess the between-session repeatability, intraclass correlations (ICC 2,1) were employed. There was poor-to-moderate repeatability for the SD (ICC: 0.357–0.545) and CV (ICC: 0.371–0.529). DFA showed poor-to-moderate repeatability (ICC: 0.013–0.504), while SE had poor repeatability (ICC: 0.133–0.226). Previous studies have shown that differences of > 0.19 in DFA and > 0.66 in SE can differentiate between healthy and pathological gait. These values are greater than this study's reported standard error of measurement, indicating that clinically meaningful changes may still be detectable despite low repeatability. • The repeatability of stride time measures during loaded marching were established • Linear and non-linear measures demonstrated poor-to-moderate repeatability • Non-linear measures had a variation of less than 10 % between sessions • Meaningful changes in stride time measures can be detected during marching [ABSTRACT FROM AUTHOR]

The operation of iontronic capacitive sensors typically requires an external alternating current (AC) power source, resulting in additional energy consumption and AC‐frequency‐related sensing performance. Here, a class of self‐powered iontronic capacitive sensing units (SICSUs) is proposed based on a dynamic electric double layer (EDL), with a significant charge sensitivity of up to 24270 pC N−1, surpassing most piezoelectric materials by nearly 10 times. The effects of various design parameters and loading conditions on the sensing performance of the SICSUs are systematically investigated. The EDL at the hydrogel‐electrode interface is characterized in situ, revealing the underlying mechanism for high sensitivity and linearity. The capability of SICSUs in detecting diverse human‐related mechanical loads is demonstrated. Furthermore, a robotic hand equipped with a SICSU‐based artificial algesia sensor is fabricated to mimic the withdrawal reflex behavior of a human hand when its skin detects noxious stimuli caused by sharp objects. [ABSTRACT FROM AUTHOR]

Large or repeated mechanical loads degrade polymeric materials by accelerating chain fragmentation. This mechanochemical backbone fracture usually occurs by homolysis of otherwise inert C–C, C–O and C–S bonds, generating highly reactive macroradicals. Because backbone fracture is detrimental on its own and the resulting macroradicals can initiate damaging reaction cascades, a major thrust in contemporary polymer mechanochemistry is to suppress it, usually by mechanochemical release of "hidden length" that dissipates local molecular strain. Here we summarize an emerging complementary strategy of channelling mechanochemically generated macroradicals in reaction cascades to form new load-bearing chemical bonds, which enables local self-healing or self-strengthening, and/or to generate mechanofluorescence, which could yield detailed quantitative molecular understanding of how material-failure-inducing macroscopic mechanical loads distribute across the network. We aim to identify generalizable lessons derivable from the reported implementations of this strategy and outline the key challenges in adapting it to diverse polymeric materials and loading scenarios. [ABSTRACT FROM AUTHOR]

In this article, the behavior of the truncated conical shell subjected to thermomechanical loading in their inner and outer layers with internal heat generation source is investigated. The displacement field obeys kinematic of the first order shear deformation theory and the first-order temperature theory is used. Two-dimensional temperature analysis has been performed along the thickness and axis of the shell, which can be defined under various loading and thermomechanical boundary conditions. The set of governing equations is a system of differential equations with variable coefficients which are solved by using the analytical matched asymptotic expansion of the perturbations technique. The mentioned solution has little computational cost, therefore can be used well in parametric studies for optimization. It was shown, axial displacement is somehow independent of the radial axis and its maximum value occurs near the upper boundary. The conical shell has expanded in the radial direction. Also the maximum temperature happens approximately in the middle of the length of the conical shell. The parametric study showed, with the increase heat flux in the outer layer thereby expanding the area of heat application which would let more heat in than out. Also it was found, controlling the lifetime of the structure is the result of directing the cone angle. The results obtained from the analytical solution were compared with the Finite Element Method (FEM) analysis and the results of similar related articles, only to show a good agreement. [ABSTRACT FROM AUTHOR]

This study presents a thermo-mechanical fracture analysis of porous functionally graded cracked plates using the extended finite element method. Three types of functionally graded cracked plates with two different types of porosity distributions, namely homogeneous and nonhomogeneous, are considered in this investigation. Specifically, edge and center-cracked porous functionally graded material plates are analyzed to determine the stress intensity factors. Thermo-mechanical loading conditions are considered to simulate the effects of temperature gradients and mechanical stresses on cracked plates. The analysis aims to investigate the influence of the crack length, crack location, porosity distribution, porosity volume fraction, crack angle, and material gradient on the SIF values. The results of the study provide valuable insights into the behavior of functionally graded cracked plates with different porosity distributions. The findings contribute to the understanding of the mechanical response of such plates under thermo-mechanical loading conditions and can aid in the design and optimization of structures made from functionally graded porous materials. [ABSTRACT FROM AUTHOR]

This study introduces extended isogeometric analysis method (XIGA) as a tool to investigate fracture behavior in isotropic and orthotropic materials under uniaxial and biaxial mechanical loads. Utilizing isogeometric analysis knot spans to discretize the problem domain and second order perturbation technique within XIGA framework derives mean and coefficient of variance values for mixed-mode stress intensity factors (MMSIFs) by considering variations in input parameters, including crack length, crack angle and material elastic properties. Mixed-mode SIF is evaluated using the proper interaction integral method subjected to different loading conditions showcases versatility of the proposed approach. The alignment between the existing literature and Monte Carlo simulations demonstrates a robust correspondence, validating the accuracy and reliability of the stochastic XIGA technique. This research establishes the efficacy of the approach in comprehensively addressing fracture analysis across different mechanical loading scenarios. [ABSTRACT FROM AUTHOR]

This paper examines the shaft resistance mobilisation ratio as a predictor of cumulative displacement of small-scale floating and end-bearing energy pile foundations subjected to vertical compressive loads embedded in dry sandy soils. A reduced friction model pile was subjected to different mechanical loads and two long-duration, cyclic heating/recovery temperature changes. The pile, soil and container temperatures, pile strains, and vertical displacements are monitored, analysed, and discussed. The results further validate numerical analyses that propose the shaft resistance mobilisation ratio as a variable to identify thresholds above which permanent cyclic thermo-induced deformations may occur. Overall, the experimentally observed responses indicate incremental deformations as the shaft resistance mobilisation ratio increased. The results also suggest that a mobilisation ratio of 66% could be a potential conservative lower-bound limit that could control the increment of thermal-induced vertical displacements in the long term under free pile head conditions. This suggests that a performance-based design would be a reasonable approach for energy piles, and monitoring programs should be set in the field before loading and thermo-activation. [ABSTRACT FROM AUTHOR]

Embedded fiber Bragg gratings are increasingly applied for in-situ strain measurement in fiber-reinforced plastics, integral to high-end aerospace equipment. Existing research primarily focuses on in-plane strain measurement, limited by the fact that fiber Bragg gratings are mainly sensitive to axial strain. However, out-of-plane strain measurement is equally important for comprehending structural deformation. The birefringence of fiber Bragg gratings shows promise for addressing this problem; yet, the strain transfer relationship between composites and optical fibers, along with the decoupling method for multi-directional strains, remains inadequately explored. This study introduces an innovative method for multi-directional strain measurement in fiber-reinforced plastics using the birefringence of a single-fiber Bragg grating. The strain transfer relationship between composites and embedded optical fibers was derived based on Kollar's analytical model, leading to the development of a multi-directional strain decoupling methodology. This method was experimentally validated on carbon fiber/polyetherimide laminates under thermo-mechanical loading. Its reliability was confirmed by comparing experimental results and finite element simulations. These findings significantly broaden the application scenarios of fiber Bragg gratings, advancing the in-situ measurement technology crucial for the next generation of high-end aerospace equipment. [ABSTRACT FROM AUTHOR]

The mechanical behaviors of the clamped laminated arch with temperature-dependent material properties under the thermal and mechanical loadings are studied in this paper. An analytical method based on the theory of thermoelasticity is proposed for predicting the exact solutions of stresses and displacements in the arch with arbitrary thickness and layer numbers. The clamped support is equivalent to a simply support with a support reaction with the unit pulse function and the Dirac function. The space state method is utilized to establish the state equation by employing the displacements and stresses as the state variables. A slice model is introduced to simplify the coefficient matrix. Based on the continuities at the interfaces, the displacement and stress relationships between the internal and external surfaces of the laminated arch are derived with the transfer matrix method. Exact solutions for the displacements and stresses can be obtained according to the stress boundary conditions on the surfaces of the laminated arch. Finally, convergence and comparison studies demonstrate the excellent efficiency and accuracy of the present method. The influences of material dependency with temperature, thermal load, and thickness-to-radius ratio on the distributions of displacements and stresses are discussed in detail. [ABSTRACT FROM AUTHOR]

This paper presents a root cause analysis case study of defective Hall effect sensor devices. The study identified a complex failure mode caused by chip–package interaction, which has a similar signature to discharging defects such as ESDFOS (electrostatic discharge from outside to surface). However, the study revealed that the defect was induced by local mechanical force applied to IC structures due to the presence of large irregular shaped filler particles within the mold compound. Extensive failure analysis work was conducted to identify the failure mode, including the development of a new backside analysis strategy to preserve the mold compound during IC defect localization and screening. A combination of different failure analysis techniques was used, including CMP delayering, PFIB trenching, SEM PVC imaging and large area FIB cross-sectioning. The study found that the mold compound of the package caused thermo-mechanical strain onto the silica filler particle due to epoxy shrinkage during the molding process. Additionally, extra-large, irregularly shaped filler particles (called twin particles), located on top of the chip surface, can cause locally high compression stresses onto the IC layers, initiating cracks in the isolation layers under certain conditions forming a leakage path over the time. Thermo-mechanical finite element analysis was applied to verify the mechanical load condition for these large irregular shaped filler particles. As a result, an additional polyimide layer was introduced onto the IC to mitigate the mechanical stress of mold compound particles to avoid this failure mode. [ABSTRACT FROM AUTHOR]

The objective of this manuscript is to examine the thermodynamical disturbances in a rotating nonlocal transversely isotropic thermoelastic solid half-space. The enunciation is applied to Lord–Shulman model of generalized thermoelasticity with Eringen's nonlocal elasticity theory. The formulation is subjected to a mechanical load. The expressions for the displacement components, stresses and temperature field are obtained by using normal mode technique and the numerical computations have been carried out with the help of MATLAB software for zinc crystal-like material. The comparisons are made among the results obtained by taking into account the different values of rotation parameter $ (\Omega =0.0, 0.1, 0.3) $ (Ω = 0.0 , 0.1 , 0.3) , nonlocal parameter $ (\varepsilon =0.195\times 10^{-9}, 0.195\times 10^{-4}, $ (ε = 0.195 × 10 − 9 , 0.195 × 10 − 4 , $ 0.195\times 10^{-1}) $ 0.195 × 10 − 1) and time $ (t=0.1, 0.3, 0.5) $ (t = 0.1 , 0.3 , 0.5). The outcomes point out a strong impact of the rotation, nonlocality and time on the physical quantities and agree with the boundary conditions. Although various studies exist in the literature for local and isotropic thermoelastic medium, but the current results are presented in an anisotropic and nonlocal thermoelastic rotating medium, which have not been studied so far. [ABSTRACT FROM AUTHOR]

In this paper, we propose a plate model, within the framework of finite-strain elasticity, to study the magneto-mechanical behaviors of hard-magnetic soft material plates. The 2D vector plate equation is derived from the 3D governing equations through a series expansion and truncation approach. The displacement and traction boundary conditions on the edges of plate samples are also proposed. Compared with the other plate or shell theories, the current plate model naturally incorporates the elastic incompressibility and the magneto-mechanical coupling effect of the material, which doesn't involve any a priori hypotheses on the geometry and deformation of the plates. Thus, it is applicable for modeling the large deformations of hard-magnetic soft material plates. To show the efficiency of the plate model, we study a benchmark problem, i.e., the plane-strain bending deformations of plate samples induced by magnetic and mechanical loads. Some analytical solutions of the plate equation system are derived, which provide accurate predictions on the magneto-mechanical response of the plate samples with different thickness-length ratios and magnetization directions. To promote applications of the plate model, we further derive a simplified plate equation system and write out its weak form, which is then implemented into the finite element software COMSOL Multiphysics. The efficiency of the simplified plate equation system is also verified through some typical examples. It is found that the numerical results obtained from the 2D plate model show good consistency with those of the 3D volume model, while the plate model exhibits obvious advantages in the aspects of numerical efficiency. • The magneto-mechanical response of hard-magnetic soft material plates is studied. • A plate model is proposed through the series-expansion and truncation approach. • Field-induced bending deformations of plate samples are studied analytically. • A simplified plate equation system is derived and its weak form is established. • Numerical simulations based on the plate model show good accuracy and efficiency. [ABSTRACT FROM AUTHOR]

Polymer nanocomposites have found ubiquitous use across diverse industries, attributable to their distinctive properties and enhanced mechanical performance compared to conventional materials. Elucidating the elastic‐to‐plastic transition in polymer nanocomposites under diverse mechanical loads is paramount for the bespoke design of materials with desired mechanical attributes. In the current work, the elastic‐to‐plastic transition is probed in model systems of polyethylene oxide (PEO) and silica, SiO2, nanoparticles, through detailed atomistic molecular dynamics simulations. This comprehensive, multi‐scale analysis unveils pivotal markers of the elastic‐to‐plastic transition, highlighting the quintessential role of microstructural and regional heterogeneities in density, strain, and stress fields, featuring the polymer‐nanoparticle interphase region. At the atomic level, the behavior of polymer chains interacting with nanoparticle surfaces is traced, differentiating between free and adsorbed chains, and identifying the microscopic origins of the linear‐to‐plastic transition. The mechanical behavior of subregions are characterized within the PEO/SiO2 nanocomposites, focusing on the interphase and bulk‐like polymer areas, probing stress heterogeneities and their decomposition into various force contributions. At the inception of plasticity, a disruption is discerned in isotropy of the polymeric density field, the emergence of low‐density regions, and microscopic voids/cavities within the polymer matrix concomitant with a transition of adsorbed chains to free. The yield strain also emerges as an inflection point in the local versus global strain diagram, demarcating the elastic limit, and the plastic regime shows pronounced strain heterogeneities. The decomposition of the atomic Virial stress into bonded and non‐bonded interactions indicates that the rigidity of the material is primarily governed by non‐bonded interactions, significantly influenced by the volume fraction of the nanoparticle. These findings emphasize the importance of the microstructural and micromechanical environment at the polymer‐nanoparticle interface on the linear‐to‐plastic transition, which is of great importance in the design of nanocomposite materials with advanced mechanical properties. [ABSTRACT FROM AUTHOR]

Ratcheting analysis for cantilever beams subjected to the thermomechanical loads is presented using the finite element method. The cantilever beam is constrained along the vertical direction, and plane stress conditions are assumed according to the bilinear isotropic hardening model. Two points are considered to obtain areas of ratcheting by using linear extrapolation. The results and output diagrams for ratcheting with elastic-perfect plastic behavior are illustrated. It was revealed that the beam behaves elastically after the first considerable plastic strain, which is seen in two shakedown regimes. The numerical results are verified with known and analytical results in the literature. The results indicate a strong correlation between the outcomes from the cyclic ANSYS Parametric Design Language (APDL) model and Bree's analytical predictions. This consistency between the finite element analysis and the analytical solutions underscores the potential of finite element analysis as a powerful tool for addressing complex engineering challenges, offering a reliable and robust alternative to traditional analytical methods. [ABSTRACT FROM AUTHOR]

Silicon nitride (Si3N4) is widely used in structural ceramics and advanced manufacturing due to its excellent mechanical properties and high-temperature stability. These applications always involve deformation under mechanical loads, necessitating a thorough understanding of their mechanical behavior and performance under load. However, the mechanical properties of Si3N4, particularly at the micro- and nanoscale, are not well understood. This study systematically investigated the mechanical properties of bulk Si3N4 and Si3N4 whiskers using in situ SEM indentation and uniaxial tensile strategies. First, nanoindentation tests on bulk Si3N4 at different contact depths ranging from 125 to 450 nm showed significant indentation size effect on modulus and hardness, presumably attributed to the strain gradient plasticity theory. Subsequently, in situ uniaxial tensile tests were performed on Si3N4 whiskers synthesized with two different sintering aids, MgSiN2 and Y2O3. The results indicated that whiskers sintered with Y2O3 exhibited higher modulus and strength compared to those sintered with MgSiN2. This work provides a deeper understanding of the mechanical behavior of Si3N4 at the micro- and nanoscale and offers guidance for the design of high-performance Si3N4 ceramic whiskers. [ABSTRACT FROM AUTHOR]

A thermo-mechanical progressive analysis model is proposed for predicting fatigue-driven delamination in composite laminated plates. The delamination is simulated based on extended layerwise method (XLWM). The traction-separation law is employed to the heat flux transfer and mechanical load transfer across the delamination front. A thermo-mechanical cohesive zone model (TM-CZM) is developed by Peerlings damage law to simulate the fatigue characteristic of delamination front. In the numerical examples, the effects of mesh lengths, acceleration multipliers, interface strengths, and cyclic temperature load magnitudes on the delamination expansion process are investigated, and the temperature-life curves of composite laminates are determined as well. [ABSTRACT FROM AUTHOR]

This paper explores the adaptation of pseudo-rigid-body models (PRBMs) for simulating large geometric nonlinear deflections in passive exoskeletons, expanding upon their traditional application in small compliant systems. Utilizing the AnyBody modeling system, this study employs force-dependent kinematics to reverse the conventional simulation process, enabling the calculation of forces from the deformation of PRBMs. A novel approach, termed "Constraint Force", is introduced to facilitate this computation. The approach is thoroughly validated through comparative analysis with laboratory trials involving a beam under bending loads. To demonstrate the functionality, the final segment of this study conducts a biomechanical simulation incorporating motion capture data from a lifting test, employing a novel passive exoskeleton equipped with flexible spring elements. The approach is meticulously described to enable easy adaptation, with an example code for practical application. The findings present a user-friendly and visually appealing simulation solution capable of effectively modeling complex mechanical load cases. However, the validation process highlights significant systematic errors in the direction and amplitude of the calculated forces (20% and 35%, respectively, in the worst loading case) compared to the laboratory results. These discrepancies emphasize the inherent accuracy challenges of the "Constraint Force" approach, pointing to areas for ongoing research and enhancement of PRBM methods. [ABSTRACT FROM AUTHOR]

Background: Surgeons often encounter patients with intestinal failure due to inadequate intestinal length ("short bowel syndrome"/SBS). Treatment in these patients remains challenging and the process of physiologic adaptation may take years to complete, which frequently requires parenteral nutrition. We propose a proof-of-concept mechanical bowel elongation approach using a self-expanding prototype of an intestinal expansion sleeve (IES) for use in SBS to accelerate the adaptation process. Methods: IESs were deployed in the small intestines of Sprague Dawley rats. Mechanical characterization of these prototypes was performed. IES length–tension relationships and post-implant bowel expansion were measured ex vivo. Bowel histology before and after implantation was evaluated. Results: IES mechanical studies demonstrated decreasing expansive force with elongation. The deployment of IES devices produced an immediate 21 ± 8% increase in bowel length (p < 0.001, n = 11). Mechanical load testing data showed that the IESs expressed maximum expansive forces at 50% compression of the initial pre-contracted length. The small-intestine failure load in the rats was 1.88 ± 21 N. Intestinal histology post deployment of the IES showed significant expansive changes compared to unstretched bowel tissue. Conclusions: IES devices were scalable to the rat intestinal model in our study. The failure load of the rat small intestine was many times higher than the force exerted by the contraction of the IES. Histology demonstrated preservation of intestinal structure with some mucosal erosion. Future in vivo rat studies on distraction enterogenesis with this IES should help to define this organogenesis phenomenon. [ABSTRACT FROM AUTHOR]

A continuum theory of pantographic lattices, based on second-grade elasticity, is presented. The proposed model is able to describe the mechanical behavior of a type of material structure made up of multiple layers of pantographic sheets connected with a third family of fibers. Thus, these materials are characterized by an orthogonal pattern of fibers that can bend, stretch and twist. Numerical experiments illustrate the predictive potential of the model when the material is subjected to different types of mechanical loads, including compression, torsion and two kinds of bending. Analyzing the material responses for these various tests makes it possible to reveal unusual deformation patterns characteristic of such "pantographic blocks." Numerical simulations using the finite element method are intended to assist in designing an experimental program using 3D-printed specimens made of different materials. [ABSTRACT FROM AUTHOR]

The aim of the present study is to elucidate the non-linear stability characteristics of randomly distributed carbon nanotube-reinforced fiber composite (RD-CNTRFC) beams subjected to thermo-mechanical loading. Effective material properties of RD-CNTRFC are estimated using the Eshelby-Mori-Tanaka approach and Halpin–Tsai micromechanical techniques. The material properties are considered to be temperature-dependent, and the influence of carbon nanotube (CNT) agglomeration is also incorporated in material properties estimation of hybrid matrix. The strain-displacement relations are assumed by incorporating the higher-order shear deformation theory and geometrical nonlinearity (von Kármán). The governing partial differential equations are obtained by minimizing the total potential energy of the beam. Buckling loads of beam subjected to in-plane compressive loads are estimated using Eigen value approach. Similarly, buckling temperatures are also determined by solving Eigenvalue problem iteratively due to temperature-dependent material properties. The non-linear equilibrium paths under thermal and mechanical loadings are traced through iterative Eigenvalue approach. Numerical results are presented to elucidate the influence of various parameters like CNT agglomeration, ply sequences, span-to-depth ratio, boundary conditions, and mass fraction of CNTs. [ABSTRACT FROM AUTHOR]

In this paper large deformation of the skew microplate made of laminated composite enhanced with graphene nanosheets is investigated using first shear deformation theory (FSDT) when the plate undergoes combination of mechanical and thermal loads. Halpin-Tsai model is utilised to model mechanical properties while for thermal properties Schapery model is considered. First, shear deformation of the plate was obtained while using Green-Lagrange tensor the non-linear strain of the microplate is extracted using the von-Karman assumptions. Then, by Modified Coupled Stress Theory (MCSD), the components of Cauchy and Couple stress tensors are specified. Finally, using Hamilton Principle the governing equation of the microplate and boundary conditions are computed. After deriving analytical governmental equation results are presented for the simple support boundary condition and the proposed model is validated by previously reported data and it proves to be promising. Primary results showed that with raising skew angle deflection and bending moment decreases which means microplate becomes more rigid in higher skew angles. Higher mechanical loads lead to higher deflections and bending moments. Four different configurations of the layers were analysed from which angle-ply configuration possessed highest deflection and bending while UD configuration revealed the lowest values of deflection and bending moment. [ABSTRACT FROM AUTHOR]

To date, the traffic-induced dynamic behavior of geosynthetic-encased stone column-supported embankments (GESC) under traffic cyclic loads accompanied by embankment consolidation has not been well studied. Three-dimensional (3D) coupled mechanical and hydraulic modeling is performed using FLAC3D, which considers the fluid flow during the lifespan of three stages: (1) embankment construction (EC): (2) consolidation (C) under embankment surcharge; and (3) cyclic loading (CYC). During the simulation, excess pore pressure, stress concentration, settlement, and lateral displacement are monitored, and the total settlement and lateral displacement could be easily obtained by accumulating the components of the three stages. Parametric analyses are conducted on the reinforcement forms and cyclic loading characteristics that include the dynamic stress amplitude and loading frequency. The ordinary stone (OSC) and GESCs could reduce the settlement and lateral displacement during each stage by improving the strength of the foundation and accelerating drainage consolidation; however, GESCs outperform the columns without geoencasement. In addition, the stress concentration ratio under embankment filling decreased with the increase in the dynamic stress amplitude and loading frequency, which led to the increase in the percentage of the cyclic loading-induced settlement to total settlement. [ABSTRACT FROM AUTHOR]

BACKGROUND: Many factors can cause disc degeneration, including aging, nutritional deficiency, and mechanical factors. The mechanical load is considered to be a very important factor, but its mechanism is still unclear. OBJECTIVE: To investigate the role of sclerostin (SOST) and Wnt/β-catenin signaling pathways in inducing degeneration of endplate cartilage. METHODS: Cartilage endplate cells were extracted from 4-week-old male Sprague-Dawley rats. Compressive stress was applied to endplate chondrocytes in vitro using a mechanical loading apparatus, and the cell viability was determined by the cell counting kit-8 assay at 1, 3, 5, and 7 days after compression. Western blot, reverse transcription quantitative PCR, and cellular immunofluorescence techniques were employed to examine intracellular cartilage markers (Aggrecan and type II collagen) as well as calcification-related factors (Runx2 and osteocalcin). The expression of extracellular matrix degradation enzyme and genes related to the signaling pathway (SOST and β-catenin) was also analyzed. RESULTS AND CONCLUSION: Under compressive stress, the cell activity of endplate chondrocytes increased with both the duration and intensity of stress. Furthermore, the expression levels of Aggrecan and type II collagen decreased in endplate cells under compressive stress, while those of calcification-related factors (Runx2 and osteocalcin) increased. Additionally, compressive stress promoted extracellular matrix degradation in endplate chondrocytes, leading to an increase in matrix metalloproteinase 3 and matrix metalloproteinase 13 expression. Abnormalities were observed in the Wnt/β-catenin signaling pathway within these cells under compressive stress, characterized by a decrease in specific inhibitory factor SOST expression accompanied by abnormal accumulation of β-catenin. To conclude, decreased SOST expression in endplate chondrocytes under compressive stress activates the Wnt/β-catenin signaling pathway, thereby promoting calcification, degeneration and extracellular matrix degradation in the cartilage endplate. [ABSTRACT FROM AUTHOR]

Understanding the contact behaviour of slewing-ring thrust ball bearings is essential for accurate predictions of load distribution and evaluations of static and dynamic load capacity. Applying Hertz's theory to non-standard slewing ring bearings presents unique challenges due to their complex geometries and difficulties in achieving uniform surface finishes, leading to significant deviations from actual stress. This study addresses these limitations by comparing experimental results, numerical results, and the Hertz theory. The analysis considers three Hertz contact configurations between the bearing ball and the raceway. The results reveal significant deviations from the experimental values. To determine the cause of these variations, the friction coefficient between the ball and the raceway is determined using the gravitational method by varying the number of balls. Uneven load distribution across balls in slewing ring bearings under mechanical loads is exposed by friction coefficient measurement. To further explore, load-deformation experiments are conducted on the LMMB by placing varying numbers of balls and their positions. Results expose variations in load-taking behaviour among the balls, emphasizing the critical influence of contact area load distribution. [ABSTRACT FROM AUTHOR]

This article presents the impact of nonlocal parameters (NLP) on wave motion and deformation in a micropolar porous thermoelastic plate under memory-dependent derivatives (MDD). The basic equations are converted into dimensionless form and solved using normal form analysis. Two cases of boundary conditions, namely boundary conditions for stress free boundaries and boundary conditions for thermo-mechanical loading, are considered. The first case of boundary conditions is employed to formulate the propagation equations for symmetric and anti-symmetric systems. The phase velocity and attenuation coefficient under Lord–Shulman (LS), Green–Lindsay (GL) and dual-phase-lag (DPL) theories are examined for the first case. In the second case, thermomechanical conditions have been considered to derive the analytical terms for force stresses, couple stresses, volume fraction, and temperature. The analytically obtained results are numerically analyzed for aluminium–epoxy material under three memory-dependent theories. To depict the impact of nonlocal parameters, comparisons between DPL theory with NLP and DPL theory without NLP are shown graphically. [ABSTRACT FROM AUTHOR]

The effect of thermo-mechanical load coupling and porosity distributions on vibration and buckling characteristics of Functionally Graded Sandwich Plates (FGSPs) with cutouts is investigated by Finite Element (FE) formulation. Two sandwich configurations are considered and physical neutral surface is incorporated due to material asymmetry. Novel dynamic approach is proposed to evaluate buckling loads. Results obtained are compared with experimental, numerical solutions in literature and revealed that the FGSP buckling capacity under thermomechanical loads improves on using ceramic with lower thermal expansion coefficient. Also, at higher temperature rises, buckling capacity increases due to increasing porosity content, whereas capacity reduces at lower temperature rises. [ABSTRACT FROM AUTHOR]

The uncertainty that characterizes the external mechanical loads to which any connection plate in steel structures is subjected determines the non-uniqueness of the isochoric deformation distributions. Since the eddy currents induced on the plates produce magnetic field maps with a high fuzziness content, similar to those of the isochoric deformations, their use can be exploited to evaluate the extent of the external load that determines a specific induced current map. Starting from an approach known in the literature, according to which the map-external load association is operated through fuzzy similarity computations, in this paper, we generalize this method by reformulating it in terms of intuitionistic fuzzy logic by proposing a classification based on divergence computations. Our approach, acting adaptively on the fuzzification of the maps, results in a better classification percentage, besides significantly reducing the presence of doubtful cases due to the uncertainty of each applied load. Furthermore, a FEM software tool was developed, which turned out to be, to a certain extent, a substitute for the experimental procedure, notoriously more expensive. Even if the procedure was applied on plates subjected to bi-axial loads, it could be used for other types of loads since the classification operator processes the eddy current maps exclusively, regardless of their cause. [ABSTRACT FROM AUTHOR]

This paper develops a mathematical framework that aims to control the temperature and rotational speed in the activation process of a gas turbine in an optimal way. These controls influence the deformation and the stress in the component due to centripetal loads and transient thermal stress. An optimal control problem is formulated as the minimization of maximal von Mises stress over a given time and over the whole component. To find a solution for this, we need to solve the linear thermoelasticity and the heat equations using the finite element method. The results for the optimal control as functions of the rotation speed and external gas temperature over time are computed by sequential quadratic programming, where gradients are computed using finite differences. The overall outcome reveals a significant reduction of approximately 10%, from 830 N/mm² to 750 N/mm², in von Mises stress by controlling two parameters, along with the temporal separation of physical control phenomena. [ABSTRACT FROM AUTHOR]

A coupling model is established on piezoelectric semiconductor bipolar junction transistors (PS-BJT) subjected to mechanical loadings by abandoning depletion layer approximation and low injection assumption. Effect of base region on device performance and interaction between emitter/base junction (E/B) and base/collector junction (B/C) are investigated. It is found that too small a base width will cause B/C to extract electrons directly from emitter region, implying that an electron passageway will be excited to link from collector- to emitter-region by striding over base-region (abbreviated as "EP-CE" hereafter). We particularly clarify that the current produced by electrons flowing across EP-CE is independent of electron-hole recombination in E/B, which means that this current has not yet been bestowed on the information of base current. "Information of base current" refers to dispatching information of base current on the electrons in emitter region. Thus, a current from EP-EC cannot be reckoned in the amplification effect of base current. Our investigations show that base width should not be designed too small to avoid EP-CE, which has not been revealed before. As regards to tuning PS-BJT performance by mechanical loadings, we revealed the mechanism as follows: 1) raising electron-hole recombination rate inside E/B to reduce resistivity such that more electrons can be driven from emitter- to base-region; 2) elevating electron conductivity in base-region for easier pass of electrons; 3) promoting attractive ability of B/C on electrons such that more electrons cross the interface. Numerical results show that transmission characteristics can be greatly increased as expected by mechanical tuning. [ABSTRACT FROM AUTHOR]

In this work we focus on the development of a numerical algorithm for the inverse elastography problem. The goal is to perform an efficient material parameter identification knowing the elastic displacement field induced by a mechanical load. We propose to define the inverse problem through a quadratic optimization program which uses the direct problem formulation to define the objective function. In this way, we end up with a convex minimization problem which attains its minimum at the solution of a linear system. The effectiveness of our method is illustrated through numeral examples. [ABSTRACT FROM AUTHOR]

Vinculin binds to specific sites of mechanically unfolded talin rod domains to reinforce the coupling of the cell's exterior to its force generation machinery. Force-dependent vinculin–talin complexation and dissociation was previously observed as contraction or extension of the unfolded talin domains respectively using magnetic tweezers. However, the structural mechanism underlying vinculin recognition of unfolded vinculin binding sites (VBSs) in talin remains unknown. Using molecular dynamics simulations, we demonstrate that a VBS dynamically refolds under force, and that vinculin can recognize and bind to partially unfolded VBS states. Vinculin binding enables refolding of the mechanically strained VBS and stabilizes its folded α-helical conformation, providing resistance against mechanical stress. Together, these results provide an understanding of a recognition mechanism of proteins unfolded by force and insight into the initial moments of how vinculin binds unfolded talin rod domains during the assembly of this mechanosensing meshwork. Author summary: Cells attach to and interact with their surroundings, and sense mechanical signals from the microenvironment. Vinculin and talin are classical examples of mechanosensitive proteins that complex in a force-dependent manner. Talin domains unfold under mechanical loads exposing buried vinculin binding sites, namely single α-helices. Such mechanical stretching enables recognition by vinculin, however, the structural states of vinculin's binding site when under force and the complexation mechanisms are poorly understood. We used molecular dynamics simulations to study the behavior of a single vinculin binding helix under mechanical load and during the initial moments of the vinculin–talin binding process. Our results reveal the highly dynamic nature of a vinculin binding helix under mechanical load. Depending on the force magnitude, the helix frequently reforms to a partially folded conformation on the nanosecond to microsecond timescale. Crucially, vinculin recognizes such partially folded helices in talin and promotes their refolding against force. Our findings are beyond the resolution limits imposed by experimental single molecule methods, suggesting a model which may be useful as a general mechanism for protein-protein binding under mechanical load. [ABSTRACT FROM AUTHOR]

Studies on Brushite, which was initially considered as a mineral found in caves, started when it was seen in kidney stones, and finally its applications continued. These studies were focused on synthetically obtaining Brushite. The biggest difficulty in obtaining Brushite synthetically is the execution of complex chemical and sequential processes at high temperatures. Obtaining a stable crystal structure at high temperatures brings another challenge. In this study, for the first time in the literature, the synthesis of Brushite at room temperature by using simple electrolyte, characterization of the precipitates with different methods, and the details of their electrochemical and mechanical behaviour were shared with the readers. Brushite was precipitated on the X2CrNiMo17‐12‐2 materials by using electrolytic method. In the characterization of Brushite deposits, energy dispersive X‐ray microanalysis (EDS), X‐ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscope (SEM), and optical microscope with image analyser were used. Dynamic ultramicro hardness, scratch, and friction‐wear testing equipment were used in mechanical analyses. It has been determined that the electrochemical decomposition of the Brushite material, which was successfully synthesized at room temperature, is quite difficult, and a mechanical load of 10 mN has been defined to be the critical value. [ABSTRACT FROM AUTHOR]

Combining the superior thermal conductivity of graphene and the outstanding heat storage of paraffin, micro-nanocavity graphene/paraffin nanocomposites (MNGPNs) have recently served as promising thermal management materials in high-power microelectronic devices. However, current evaluations of the thermal management performances of MNGPNs are restricted in the lab condition, deviating from the complex mechanical–thermal coupling environment in practical scenarios. Here, we have investigated the structural and thermal management properties of MNGPNs with varying mechanical loads by in situ electron microscopy and in situ thermal characterizations. Our results reveal distinct mechanical–thermal coupling effects along in-plane and out-of-plane directions of MNGPNs. Specifically, mechanical loading reduces the porosity and enhances the heat transfer capacity of MNGPNs in the out-of-plane direction, while mechanical loading along the in-plane direction causes local damage to the graphene structure and weakens the heat transfer capacity of MNGPNs. Since the heat management performance of MNGPNs is dominated by the in-plane thermal transport, MNGPNs with mechanical loading show a delayed phase transition response time and unchanged phase transition enthalpy. This work provides in situ mechanical guidance for the practical application of MNGPNs for heat management. [ABSTRACT FROM AUTHOR]

One of the most important problems is the stripping of the rope, which is a part of the drum-rope mechanisms required in the weight lifting operations used in today's crane systems, from the drum rope clamps under load. This article is a new study in the literature. In this study, the focus is on investigating the design and process parameters of the drum rope clamps used on the drum mechanisms in overhead cranes, simplifying and improving the production. In order to fulfil this objective, firstly, a prototype table-top experimental system that constructs a drum-rope connection has been established. In the experimental study, flat and radius clamps were used as design parameters and the squeezing forces of the bolts connecting the clamps to the drum were considered as process parameters. The tensile force to be applied throughout the study was obtained by making various mathematical calculations. Finally, it was concluded that design and process parameters have significant effects on crane drum-rope systems and comparisons were made on drum rope clamp designs. In addition, it is seen from the experimental results that it has an impact on cost and operational efficiency. [ABSTRACT FROM AUTHOR]

This work focuses on the bending examination of three-dimensional (3D) functionally graded carbon nanotube (CNT) reinforced composite (FG-CNTRC) cylindrical shell exposed to internal pressure. The composite cylindrical shell is assumed to be reinforced in the longitudinal axis. Mechanical properties of the constituents are applied based on the modified rule of the mixture. Distribution of CNTs across the shell thickness is assumed to be uniform and three types of functionally gradients. The governing equations are developed using the Principle of Virtual Displacements (PVDs) based on Carrera's Unified Formulation (CUF) and then differential quadrature method (DQM) is used to solve the governing equations for different combinations of simply supported and clamped boundary conditions. The comparison studies between the obtained results and those available in the literature demonstrate the accuracy and computational efficiency of the present formulation and method. The roles of different factors including the volume fraction of CNTs ( V CN * ), boundary conditions, distributions of CNTs, length-to-radius ratios ( L / r), and mechanical loads, are investigated in the outcomes. The results illustrate that the non-dimensional maximum deflections of functionally graded (FD) distributions are higher than the uniform distributions for different boundary conditions. [ABSTRACT FROM AUTHOR]

Aim: This study aimed to investigate the influence of titanium base (ti‐base) abutment macro‐ and micro‐geometry on the mechanical stability of polymer‐infiltrated ceramic network (PICN) screw‐retained implant‐supported single crowns (iSCs). Materials and Methods: Twelve specimens per group were used, comprising six different implant/ti‐base abutment combinations restored with PICN iSCs: Nb‐T (gingival height [GH]: 1.5 mm, prosthetic height [PH]: 4.3 mm), CC (GH: 0.8 mm, PH: 4.3 mm), CC‐P (GH: 0.8 mm, PH: 7 mm), Nb‐V (GH: 1.5 mm, PH: 6 mm), St (GH: 1.5 mm, PH: 5.5 mm), and Th (GH: 0.5 mm, PH: 9 mm). The specimens underwent thermo‐mechanical aging, and those that survived were subsequently subjected to static loading until failure. The data were analyzed using a one‐way ANOVA test followed by Tukey post hoc test (α =.05). Results: All specimens survived thermo‐mechanical aging without complications, namely, visible cracks, debonding, or screw loosening. Th group demonstrated the highest strength values among all the groups, with significant differences compared to Nb‐T (p <.05), CC (p <.001), and St (p <.001). Additionally, CC‐P group exhibited significantly superior fracture strength results compared to CC (p <.05) and St (p <.05). Conclusion: The choice of ti‐base, particularly prosthetic height, had a significant influence on fracture resistance of PICN iSCs. Nevertheless, the height or geometrical features of the ti‐base did not exhibit a significant influence on the mechanical behavior of the iSC/ti‐base assembly under thermomechanical loading, as all specimens withstood the aging without complication or failure. [ABSTRACT FROM AUTHOR]

This study aims to evaluate and compare the mechanical resistance, fatigue behavior and fracture behavior of different CAD/CAM materials for implant crowns. Eighty-eight implant crowns cemented-screwed with four sample groups: two monolithic G1 Zirconia (control) and G3 composite and two bi-layered G2 customized zirconia/composite and G4 prefabricated zirconia/composite. All static and dynamic mechanical tests were conducted at 37 °C under wet conditions. The fractographic evaluation of deformed and/or fractured samples was evaluated via electron microscopy. Statistical analysis was conducted using Wallis tests, which were performed depending on the variables, with a confidence interval of 95%, (p < 0.05). The Maximum Fracture Strength values displayed by the four groups of samples showed no statistically significant differences. The crown–abutment material combination influenced the failure mode of the restoration, transitioning from a fatigue fracture type located at the abutment–analog connection for monolithic materials (G1 and G3) to a brittle fracture located in the crown for bi-layered materials (G2 and G4). The use of layered crown materials with functional gradients appears to protect the crown/abutment connection area by partially absorbing the applied mechanical loads. This prevents catastrophic mechanical failures, avoiding long chairside time to solve these kinds of complications. [ABSTRACT FROM AUTHOR]

Study Design: A prospective experimental study. Purpose: This biomechanical in vitro study aimed to examine the extent to which the use of a rod persuader (RP) leads to additional mechanical stress on the screw–rod system and determine its influence on the bony anchoring of primary pedicle screws. Overview of Literature: Degenerative spine diseases and deformities are the most common indications for the stabilization and fusion of spinal segments. The pedicle screw–rod system is considered the gold standard for dorsal stabilization, and an RP is also increasingly being considered to fit the spondylodesis material. Methods: Ten lumbar spines from body donors were examined. Bisegmental dorsal spinal lumbar interbody fusion of the L3–L5 segments was performed using a pedicle screw–rod system (ROCCIA Multi-LIF Cage; Silony Medical, Germany). In group 1, the titanium rod was inserted without tension, whereas in group 2, the rod was attached to the pedicle screws at the L4 and L5 levels, creating a 5-mm gap. To attach the rod, the RP was used to press the rod into the pedicle screw. The rod was left in place for 30 minutes and then removed. Results: The rod reduction technique significantly increased the mechanical load on the overall construct measured by strain gauges (p<0.05) and resulted in outright implant failure with pedicle screw pullout in 88.9%. Conclusions: In cases where the spondylodesis material is not fully attached within the pedicle screw, an RP can be used with extreme caution, particularly in osteoporotic bones, to avoid pedicle screw avulsion and screw anchor failure. [ABSTRACT FROM AUTHOR]

When strength training (ST) sets are performed to muscular failure over successive sets, a reduction in performance is expected, which would compromise training volume (TV). One method to sustain repetitions and limit the volume impairment is to acutely reduce the load over successive sets. However, previous studies did not investigate this load reduction in different exercise orders. The aim of the present study was to investigate the effect of progressive 10% load reductions on TV with different exercise orders. Eleven healthy men performed four protocols: multi- to single-joint (MS) protocol and single- to multi-joint (SM) protocol were performed with a constant 10-RM load or with a 10% load reduction over successive sets (MS10 and SM10), respectively. The results showed that the two load reduction protocols had significantly greater TV versus the two protocols without load reduction, independent of the order (P < 0.05). Significantly greater total volume was achieved on the last exercise of a sequence with load reduction versus without load reduction (P > 0.05). Training volume can be maintained more effectively when a load reduction of 10% is progressively applied over successive sets. [ABSTRACT FROM AUTHOR]

The paper proposes a spectral decomposition–based approach for implementing a multisurface coupled damage–plasticity model for concrete subjected to fire. The multisurface approach enables distinct flow rules to be used for plastic flow in compression and tension. The spectral decomposition–based procedure enables, for general multiaxial loading, the Jacobian for the return mapping algorithm to be determined analytically without the need for finite difference approximations or additional nested iterations. The proposed approach, developed in the context of a general multisurface plasticity model subject to the small strain assumption, is specialized to the case of a combined Drucker-Prager and Rankine yield surface, and can account for situations where the eigenvalues of the stress tensor are degenerate. It is verified by solving finite element models for concrete structural components subjected to high temperature under a wide variety of mechanical loads. The simulation results, obtained using a sequentially coupled approach, are found to closely match established experimental results. [ABSTRACT FROM AUTHOR]

Electrostatically actuated MEMS plate devices have many potential applications as micro-actuators and highly sensitive sensors. Bistability may occur in microplate devices and it refers to two stable configurations for a single value of actuating load. In this work, bistable behaviour of initially curved rectangular microplates, under the electrostatic and mechanical load actuation, has been investigated. In which detail investigation of bistability in load-deflection equilibrium paths and their associated characteristics, and later, resonance frequency behaviour in bistable regions have been carried out. For this, the governing differential equations of an initially curved rectangular plate have been developed using Kirchhoff's plate theory, including von Karman nonlinearity. Then, Galerkin's principle has been used to develop reduced order model of the governing partial differential equation of motion. To validate the results of reduced order model, we have carried out finite element analysis using a software COMSOL Multiphysics. We have observed qualitatively distinct behaviour in bistability characteristics of electrostatically and mechanically actuated microplates. We have also observed high sensitivity near bistability points and these points can be tuned by varying device parameters. This investigation could potentially help design bistable MEMS devices. [ABSTRACT FROM AUTHOR]

In this paper, the cyclic elastic–plastic behaviors of the centrifugal steam compressor impeller (CSCI) structure under practical operating conditions are discussed employing the linear matching method (LMM). The three‐stage strategy of the LMM is employed to determine the shakedown and ratchet boundaries by conducting a series of iterative direct steady cyclic analysis, and based on this, the load regions corresponding to different types of damage behavior that may occur during the operation are identified. Computational results reveal slight contraction in the structural response diagram when considering actual material constitutive relationships, compared to ideal elastic–plastic models. Meanwhile, by integrating the unified ratchet and fatigue program with fatigue experimental data, a series of constant low‐cycle fatigue life curves has been presented for different service conditions. Furthermore, a comparison with detailed step‐by‐step inelastic analyses confirms the applicability and great efficiency of the LMM in practical engineering problems. Highlights: The cyclic elastic‐plastic behavior of impeller were investigated using the three‐stage procedure.The effect of temperature‐dependent and strain hardening on structural response of impeller were evaluated.The constant low‐cycle life fatigue curves of the impeller structure were generated.The applicability and great efficiency of linear matching method have been confirmed. [ABSTRACT FROM AUTHOR]

High-performance structural materials (HPSMs) are needed for the successful and safe design of fission and fusion reactors. Their operation is associated with unprecedented fluxes of high-energy neutrons and thermomechanical loadings. In fission reactors, HPSMs are used, e.g., for fuel claddings, core internal structural components and reactor pressure vessels. Even stronger requirements are expected for fourth-generation supercritical water fission reactors, with a particular focus on the HPSM's corrosion resistance. The first wall and blanket structural materials in fusion reactors are subjected not only to high energy neutron irradiation, but also to strong mechanical, heat and electromagnetic loadings. This paper presents a historical and state-of-the-art summary focused on the properties and application potential of irradiation-resistant alloys predominantly strengthened by an oxide dispersion. These alloys are categorized according to their matrix as ferritic, ferritic–martensitic and austenitic. Low void swelling, high-temperature He embrittlement, thermal and irradiation hardening and creep are typical phenomena most usually studied in ferritic and ferritic martensitic oxide dispersion strengthened (ODS) alloys. In contrast, austenitic ODS alloys exhibit an increased corrosion and oxidation resistance and a higher creep resistance at elevated temperatures. This is why the advantages and drawbacks of each matrix-type ODS are discussed in this paper. [ABSTRACT FROM AUTHOR]

Structural supercapacitors that simultaneously bear mechanical loads and store electrical energy have exciting potential for enhancing the efficiency of various mobile systems. However, a significant hurdle in developing practical structural supercapacitors is the inherent trade‐off between their mechanical properties and electrochemical capabilities, particularly within their electrolytes. This study demonstrates a tough polymer electrolyte with enhanced multifunctionality made through the controlled hydration of a solid polymer electrolyte with poly(lactic acid) (PLA) and lithium salts. Characterization via differential scanning calorimetry, X‐ray diffraction, and Fourier transform infrared spectroscopy confirms the consistent amorphous solid solution phase in varying salt concentrations, whether dried or hydrated. Electrochemical tests and tensile tests are performed to evaluate the ionic conductivity and mechanical properties of these electrolytes. The results indicate that the strategic incorporation of water in the polymer electrolyte significantly enhances the ionic conductivity while preserving its mechanical properties. A specific composition demonstrated a remarkable increase in ionic conductivity (3.11 µS cm−1) coupled with superior toughness (15.4 MJ m−3), significantly surpassing the base polymer. These findings open new horizons for integrating electrochemical functionality into structural polymers without compromising their mechanical properties. Additionally, the paper reports the successful fabrication and testing of structural supercapacitor prototypes combining carbon fibers with fabricated electrolytes, showcasing their potential for diverse applications. [ABSTRACT FROM AUTHOR]