今日更新：International Journal of Solids and Structures 4 篇，Journal of the Mechanics and Physics of Solids 2 篇，Mechanics of Materials 1 篇，International Journal of Plasticity 1 篇，Thin-Walled Structures 1 篇International Journal of Solids and StructuresA method to analyze the axisymmetric problem of FRP laminated tubes based on singularity correctionZhang Hengming, Li Feng, Li Ruoyudoi:10.1016/j.ijsolstr.2023.112507基于奇异性校正的玻璃钢层压管轴对称问题分析方法In order to solve the problem of singularity in the stress and strain calculation process of FRP laminated tubes with arbitrary layer angles under axisymmetric thermomechanical loading, a three-dimensional elasticity theory analysis method based on singularity correction by modifying the stiffness matrix coefficients is proposed. Firstly, the basic three-dimensional elasticity theory model for FRP laminated tubes under axisymmetric thermomechanical loading is established through the displacement method. Then, the singularity plies in the laminate are determined, and the stiffness matrix coefficients of the singularity plies are modified respectively. Modifications to the displacement function coefficients, stiffness coefficients, boundary condition, and interlayer continuous condition equilibrium equations are also conducted subsequently. Verifications of the present approach are conducted by comparing the stress distributions calculated by the singularity correction method with those extracted by traditional isotropic elasticity models and then with numerical results provided by finite element analysis. Good consistency was obtained; thus, the correctness of the theory is proved from both theoretical and numerical aspects.通过位移法确定了在轴对称热机械载荷作用下的 d 管。然后，确定层压板中的奇异层，并分别修改奇异层的刚度矩阵系数。随后还对位移函数系数、刚度系数、边界条件和层间连续条件平衡方程进行了修改。通过比较奇异点修正法计算出的应力分布与传统各向同性弹性模型提取的应力分布，以及有限元分析提供的数值结果，对本方法进行了验证。结果显示两者具有良好的一致性，因此从理论和数值两方面证明了该理论的正确性。Experimental and Numerical Study of Low-Velocity Impact Damage in Sandwich Panel with UHMWPE Composite FacingsYang Bin, Zhou Qi, Lee Juhyeong, Li Yan, Fu Kunkun, Yang Dongmindoi:10.1016/j.ijsolstr.2023.112519带超高分子量聚乙烯（UHMWPE）复合材料面层的夹芯板低速冲击损伤的实验和数值研究This paper is concerned with the low-velocity impact (LVI) response behaviour of sandwich composite panels (SCPs) with ultra-high molecular weight polyethylene (UHMWPE) composite facings and Polyvinyl Chloride (PVC)/Polyethylene Terephthalate (PET) foam cores. A series of LVI tests with SCPs subjected to 50 J, 80 J and 110J were conducted to examine their impact characteristics and damage mechanisms. LVI-induced internal damage in the SCPs were characterised by compute micro-tomography (μCT) analysis. The effects of UHMWPE areal density and foam type on the LVI responses and associated failure modes of the panels were also examined. The experimental results showed that the SCP with a PET foam core exhibited higher impact strength and energy absorption performance than those of the panel with a PVC foam core. In addition, a finite element (FE) model incorporating the Puck’s failure criteria, cohesive law and crushable foam plasticity model was developed and validated to predict the intra- and inter-laminar damages of SCPs. Finally, several failure mechanisms (fibre failure, matrix cracking and local delamination) of SCPs during LVI was thoroughly discussed. The results show the UH170-PET specimen has the best impact resistance and energy absorption performance. The parametric analysis of the areal density and foam type has revealed that these parameters can be optimised for the best LVI resistance of SCPs. These findings are helpful for designing lightweight foam-based sandwich composite structures with superior impact resistance.本文主要研究带有超高分子量聚乙烯（UHMWPE）复合面层和聚氯乙烯（PVC）/聚对苯二甲酸乙二醇酯（PET）泡沫芯材的夹层复合板（SCP）的低速冲击（LVI）响应行为。对 SCP 进行了 50J、80J 和 110J 的一系列 LVI 试验，以检查其冲击特性和损坏机制。通过计算显微层析（μCT）分析，确定了 LVI 在 SCP 中引起的内部损伤的特征。此外，还研究了超高分子量聚乙烯的等密度和泡沫类型对 LVI 响应和面板相关破坏模式的影响。实验结果表明，采用 PET 泡沫芯材的 SCP 比采用 PVC 泡沫芯材的面板具有更高的冲击强度和能量吸收性能。此外，还开发并验证了一个有限元（FE）模型，该模型结合了帕克失效准则、内聚律和可压缩泡沫塑性模型，用于预测 SCP 的层内和层间破坏。最后，深入讨论了 SCP 在 LVI 期间的几种破坏机制（纤维破坏、基质开裂和局部分层）。结果表明，UH170-PET 试样具有最佳的抗冲击性能和能量吸收性能。对等密度和泡沫类型的参数分析表明，可以通过优化这些参数来获得 SCP 的最佳抗 LVI 性能。这些发现有助于设计抗冲击性能优越的轻质泡沫夹层复合材料结构。A nonlinear finite element framework and Gaussian process-based prediction of stick/slip behaviour in semi-parallel wire cablesBendalla Abdulmagid S.Kh., Tondo Gledson Rodrigo, Morgenthal Guidodoi:10.1016/j.ijsolstr.2023.112522非线性有限元框架和基于高斯过程的半平行导线电缆粘滑行为预测This paper addresses the effect of wire slipping on the mechanical properties of structural cables. Based on parameter calibration with experimental data, the paper proposes a Finite Element modelling framework aimed at enhancing the prediction accuracy of the stick/slip behaviour of semi-parallel wire (SPW) cables. The model considers the specific arrangement of the SPW cable composition, interwire friction, and residual interlock between wires. Gaussian Process regression is employed as a surrogate model to reduce the model’s computational cost, optimise parameters and quantify uncertainty. The results show high prediction accuracy when compared with experimental data for different pretension forces. The study finds that wire slip varies considerably between wire layers and is significantly influenced by residual interlock between wires. Additionally, cyclic loading under high bending curvatures reveals that the hysteresis behaviour is dependent on wire slip and loading history. The proposed model accurately predicts the stick/slip behaviour of SPW cables, emphasising the importance of accounting for wire slipping in cable analysis models for various applications.本文探讨了钢丝滑动对结构缆线机械性能的影响。基于实验数据的参数校准，本文提出了一个有限元建模框架，旨在提高半平行线 (SPW) 电缆粘滑行为的预测精度。该模型考虑了半平行导线 (SPW) 电缆成分的特定排列、导线间摩擦和导线间的残余互锁。采用高斯过程回归作为替代模型，以降低模型的计算成本、优化参数并量化不确定性。结果表明，与不同预拉力的实验数据相比，预测精度很高。研究发现，导线滑移在导线层之间变化很大，并受到导线之间残余互锁的显著影响。此外，高弯曲曲率下的循环加载显示，滞后行为取决于钢丝滑移和加载历史。所提出的模型能准确预测 SPW 电缆的粘滞/滑移行为，强调了在各种应用的电缆分析模型中考虑导线滑移的重要性。The key to the enhanced performance of slab-like topologically interlocked structures with non-planar blocksKoureas Ioannis, Pundir Mohit, Feldfogel Shai, Kammer David S.doi:10.1016/j.ijsolstr.2023.112523提高带有非平面块体的板状拓扑互锁结构性能的关键所在Topologically interlocked structures are assemblies of interlocking blocks that hold together solely through contact. Such structures have been shown to exhibit high strength, energy dissipation, and crack arrest properties. Recent studies on topologically interlocked structures have shown that both the peak strength and work-to-failure saturate with increasing friction coefficient. However, this saturated structural response is only achievable with nonphysically high values of the friction coefficient. For beam-like topologically interlocked structures, non-planar blocks provide an alternate approach to reach similar structural response with friction properties of commonly used materials. It remains unknown whether non-planar blocks have similar effects for slab-like assemblies, and what the achievable structural properties are. Here, we consider slab-like topologically interlocked structures and show, using numerical simulations, that non-planar blocks with wave-like surfaces allow for saturated response capacity of the structure with a realistic friction coefficient. We further demonstrate that non-planar morphologies cause a non-linear scaling of the work-to-failure with peak strength and result in significant improvements of the work-to-failure and ultimate deflection – values that cannot be attained with planar-faced blocks. Finally, we show that the key morphology parameter responsible for the enhanced performance of non-planar blocks with wave-like surfaces is the local angle of inclination at the hinging points of the loaded block. These findings shed new light on topologically interlocked structures with non-planar blocks, allowing for a better understanding of their strengths and energy absorption.拓扑互锁结构是由互锁块组成的组合体，它们仅通过接触就能固定在一起。此类结构已被证明具有很高的强度、能量消耗和抗裂性能。最近对拓扑互锁结构的研究表明，随着摩擦系数的增加，峰值强度和功至破坏值都会达到饱和。然而，这种饱和结构响应只有在摩擦系数达到非物理高值时才能实现。对于类似梁的拓扑互锁结构，非平面块体提供了另一种方法，利用常用材料的摩擦特性达到类似的结构响应。至于非平面砌块对于板状组合体是否具有类似效果，以及可实现的结构特性如何，目前仍是未知数。在此，我们考虑了板状拓扑互锁结构，并通过数值模拟表明，具有波浪状表面的非平面块体可使结构在实际摩擦系数下达到饱和响应能力。我们进一步证明，非平面形态会导致功至破坏值与峰值强度的非线性比例关系，并显著改善功至破坏值和极限挠度--这些值是平面块体无法达到的。最后，我们表明，波状表面的非平面砌块性能增强的关键形态参数是加载砌块铰接点的局部倾斜角。这些发现为非平面砌块的拓扑互锁结构提供了新的思路，使我们能够更好地理解它们的强度和能量吸收。Journal of the Mechanics and Physics of SolidsMeLM, a generative pretrained language modeling framework that solves forward and inverse mechanics problemsBuehler Markus J.doi:10.1016/j.jmps.2023.105454MeLM ，一个生成式预训练语言建模框架，可解决正向和反向力学问题We report a flexible multi-modal mechanics language model, MeLM, applied to solve various nonlinear forward and inverse problems, that can deal with a set of instructions, numbers and microstructure data. The framework is applied to various examples including bio-inspired hierarchical honeycomb design, carbon nanotube mechanics, and protein unfolding. In spite of the flexible nature of the model-which allows us to easily incorporate diverse materials, scales, and mechanical features-the model performs well across disparate forward and inverse tasks. Based on an autoregressive attention-model, MeLM effectively represents a large multi-particle system consisting of hundreds of millions of neurons, where the interaction potentials are discovered through graph-forming self-attention mechanisms that are then used to identify relationships from emergent structures, while taking advantage of synergies discovered in the training data. We show that the model can solve complex degenerate mechanics design problems and determine novel material architectures across a range of hierarchical levels, providing an avenue for materials discovery and analysis. To illustrate the use case for broader possibilities, we outline a human-machine interactive MechGPT model, here trained on a set of 1,103 Wikipedia articles related to mechanics, showing how the general framework can be used not only to solve forward and inverse problems but in addition, for complex language tasks like summarization, generation of new research concepts, and knowledge extraction. Looking beyond the demonstrations reported in this paper, we discuss other opportunities in applied mechanics and general considerations about the use of large language models in modeling, design, and analysis that can span a broad spectrum of material properties from mechanical, thermal, optical, to electronic.我们报告了一种灵活的多模态力学语言模型 MeLM，它可用于解决各种非线性正演和反演问题，并能处理一系列指令、数字和微观结构数据。该框架适用于各种实例，包括生物启发的分层蜂窝设计、碳纳米管力学和蛋白质展开。尽管该模型非常灵活--我们可以轻松地将各种材料、尺度和机械特征纳入其中--但该模型在不同的正演和反演任务中都表现出色。基于自回归注意模型，MeLM 有效地代表了一个由数亿个神经元组成的大型多粒子系统，其中的相互作用势能是通过图形成的自我注意机制发现的，然后利用这些机制从出现的结构中识别关系，同时利用在训练数据中发现的协同作用。我们的研究表明，该模型可以解决复杂的退化力学设计问题，并确定一系列层次结构的新型材料架构，为材料发现和分析提供了一条途径。为了说明更广泛的可能性，我们概述了一个人机交互 MechGPT 模型，该模型是在一组 1,103 篇与力学相关的维基 百科文章中训练出来的，展示了通用框架如何不仅可用于解决正向和反向问题，还可用于复杂的语言任务，如总结、生成新的研究概念和知识提取。除了本文报告的演示之外，我们还讨论了应用力学中的其他机会，以及在建模、设计和分析中使用大型语言模型的一般考虑因素，这些因素可涵盖从机械、热学、光学到电子学等广泛的材料特性。The mechanics of embedded fiber networksKakaletsis Sotirios, Lejeune Emma, Rausch Manueldoi:10.1016/j.jmps.2023.105456嵌入式光纤网络的力学原理Fiber networks underlie the mechanical behavior of a wide range of natural and engineered materials. Interestingly, these networks are often embedded within amorphous matrices rather than appearing in isolation. However, despite their frequent occurrence as embedded rather than isolated networks, few prior studies have focused on investigating the role of embedding on the emergent mechanical behavior of these systems. To address this, we adopt a mortar-type embedding approach within the finite element framework and perform simulations to systematically fill this knowledge gap. Within this study, we focus on soft tissues as an exemplary class of materials where embedded fiber networks are essential to mechanical function. Specifically, we investigate the role of embedding on the strain energy distribution within the networks across the bending, stretching, torsional, and shear fiber-level loading modes. Therein, we specifically focus on semi-flexible fiber networks. In addition to revealing the role of embedding on the networks themselves, we also investigate how the networks affect the mechanics of the matrix material. Together, we find that embedding fundamentally alters the mechanics of semi-flexible fiber networks and the surrounding matrices. Most importantly, we find that embedding semi-flexible fiber networks leads to strain-stiffening and negative Poynting effect of the resulting composite material. Furthermore, semi-flexible fiber networks induce stress heterogeneity in their host material and increase its resistance to compression. Overall, our work improves our fundamental understanding of an important class of materials. By making our implementation openly available, we also hope to help others learn more about embedded semi-flexible fiber networks in the context of materials other than soft tissues.纤维网络是各种天然材料和工程材料力学行为的基础。有趣的是，这些网络通常嵌入无定形基质中，而不是孤立存在。然而，尽管这些纤维网络经常以嵌入式而非孤立式的形式出现，但之前很少有研究关注嵌入式对这些系统出现的机械行为所起的作用。为了解决这个问题，我们在有限元框架内采用了砂浆型嵌入方法，并进行了模拟，以系统地填补这一知识空白。在这项研究中，我们将软组织作为一类典范材料，在这类材料中，嵌入式纤维网对机械功能至关重要。具体来说，我们研究了嵌入对弯曲、拉伸、扭转和剪切纤维级加载模式下网络内应变能分布的作用。其中，我们特别关注半柔性纤维网络。除了揭示嵌入对网络本身的作用，我们还研究了网络如何影响基体材料的力学。我们发现，嵌入从根本上改变了半柔性纤维网络和周围基质的力学结构。最重要的是，我们发现嵌入半柔性纤维网会导致复合材料产生应变刚度和负波因廷效应。此外，半柔性纤维网还能在其主材料中产生应力异质性，并增强其抗压性。总之，我们的工作提高了我们对一类重要材料的基本认识。通过公开我们的实现方法，我们还希望帮助其他人更多地了解软组织以外材料中的嵌入式半柔性纤维网。Mechanics of MaterialsStochastic modeling of spatially-dependent elastoplastic parameters in 316L stainless steel produced by direct energy depositionChu Shanshan, Iliopoulos Athanasios, Michopoulos John, Steuben John, Thomas James, Guilleminot Johanndoi:10.1016/j.mechmat.2023.104821通过直接能量沉积法生产的 316L 不锈钢中空间相关弹塑性参数的随机建模The stochastic modeling and calibration of an anisotropic elasto-plastic model for additive manufacturing materials are addressed in this work. We specifically focus on 316L stainless steel, produced by directed energy deposition. Tensile specimens machined from two additive manufactured (AM) box-structures were used to characterize material anisotropy and random spatial variations in elasticity and plasticity material parameters. Tensile specimens were cut parallel (horizontal) and perpendicular (vertical) to the AM deposition plane and were indexed by location. These results show substantial variability in both regimes, with fluctuation levels that differ between specimens loaded in the parallel and perpendicular build directions. Stochastic representations for the stiffness and Hill’s criterion coefficients random fields are presented next. Information-theoretic models are derived within the class of translation random fields, with the aim of promoting identifiability with limited data. The approach allows for the constitutive models to be generated on arbitrary geometries, using the so-called stochastic partial differential approach (to sampling). These representations are then partially calibrated using the aforementioned experimental results, hence enabling subsequent propagation analyses. Sampling is finally exemplified on the considered structure.本研究针对增材制造材料的各向异性弹塑性模型进行随机建模和校准。我们特别关注通过定向能沉积法生产的 316L 不锈钢。从两个增材制造（AM）箱体结构中加工出的拉伸试样被用来表征材料的各向异性以及弹性和塑性材料参数的随机空间变化。拉伸试样平行（水平）和垂直（垂直）于 AM 沉积平面切割，并按位置进行索引。这些结果表明，在这两种情况下都存在很大的变异性，在平行和垂直构建方向上加载的试样波动程度不同。接下来将介绍刚度和希尔准则系数随机场的随机表示法。在平移随机场类别中导出了信息论模型，目的是在数据有限的情况下提高可识别性。这种方法允许使用所谓的随机偏微分方法（采样）在任意几何图形上生成构成模型。然后利用上述实验结果对这些表征进行部分校准，从而实现后续的传播分析。最后在所考虑的结构上对取样进行了示范。International Journal of PlasticityTowards ultra-high strength dual-phase steel with excellent damage tolerance: the effect of martensite volume fractionLiu Lang, Li Liejun, Liang Zhiyuan, Huang Mingxin, Peng Zhengwu, Gao Jixiang, Luo Zhichaodoi:10.1016/j.ijplas.2023.103778开发具有优异损伤耐受性的超高强度双相钢：马氏体体积分数的影响Ultra-high strength (> 1 GPa) dual-phase (DP) steels have been extensively investigated in literature. Yet, the damage tolerance of these DP steels remains mostly unexplored, whereas this parameter is crucial for the sheet formability and anti-crushing performance. In this work, a medium-Mn DP steel was proposed in order to develop strong but damage-resistant DP steel by refining the microstructure. Ultra-fine grained (< 1 µm) DP steels were obtained by a simple cold rolling and intercritical annealing process. The developed DP steel can achieve an outstanding ultimate tensile strength (UTS) of over 1470 MPa with appreciable elongation to failure (EtF) of over 9% when the martensite volume fraction (Vm) is 55%. Higher Vm results in higher strength. However, the fracture strain, which is connected with damage tolerance, decreases significantly with increasing Vm, and it is even much lower than that of a full-martensite steel. Furthermore, the necking behaviour transfers from diffuse plus localized necking to diffuse necking with increasing Vm. The sufficient ferrite content in the proposed DP1470 steel enables void growth after nucleation, consequently leading to the occurrence of localized necking and higher fracture strain. Thus, a moderate Vm ranging from 45% to 65% is suggested for the development of a 1470 MPa grade DP steel with excellent damage tolerance.超高强度（> 1 GPa）双相（DP）钢已在文献中得到广泛研究。然而，这些 DP 钢的损伤耐受性大多仍未得到研究，而这一参数对钢板的成型性和抗破碎性能至关重要。本研究提出了一种中锰 DP 钢，旨在通过细化微观结构来开发强度高且抗损伤的 DP 钢。通过简单的冷轧和临界退火工艺，获得了超细粒度（< 1 µm）的 DP 钢。当马氏体体积分数（Vm）为 55% 时，所开发的 DP 钢可达到超过 1470 兆帕的出色极限抗拉强度（UTS）和超过 9% 的显著失效伸长率（EtF）。Vm 越高，强度越高。然而，与损伤容限相关的断裂应变却随着 Vm 的增加而显著降低，甚至远低于全马氏体钢的断裂应变。此外，随着 Vm 的增加，颈缩行为从弥散加局部颈缩转变为弥散颈缩。拟议的 DP1470 钢中铁素体含量充足，成核后空隙增大，从而导致局部缩颈和更高的断裂应变。因此，建议采用 45% 至 65% 的适度 Vm 来开发具有优异损伤耐受性的 1470 兆帕级 DP 钢。Thin-Walled StructuresResidual Stresses in Circular Steel Tubular Columns Repaired by Laser-Cladding Additive ManufacturingKang Lan, Zhang Cheng, Bradford Mark A., Liu Xinpeidoi:10.1016/j.tws.2023.111275用激光熔覆快速成型技术修复圆形钢管柱的残余应力This paper presents a study that investigates the magnitude and distribution of residual stress (RS) in laser cladding (LC) repaired circular steel tubular columns. The study involves experimental tests and numerical simulation. The familiar blind-hole method is employed in the experimental investigation for two RS measurement tests, while the finite element method is used for numerical thermal-mechanical analysis to obtain the temperature field and RS field. The results indicate the presence of residual tensile stress in the LC sheet and its surrounding area. The RS in the LC sheet area and in the vicinity of the LC sheet-substrate boundary is much greater than that in the substrate area located far away from the LC sheet. Additionally, the RS in the LC sheet along the scanning direction is larger than that perpendicular to the scanning direction. Nevertheless, the RS values in both the LC sheet and substrate are less than their respective yield strength values. The temperature-time cooling curves obtained from the finite element analysis, which simulate the laser cladding process for repairing the circular steel tubular column, are used to develop a theoretical model for predicting the RS in the LC sheet. A simplified RS model is proposed based on the thermal-mechanical theory, utilising the linear-exponential two-stage cooling curve. Comparisons between the experimental results and the theoretical results that are predicted using the proposed simplified RS model show both results to be in good agreement. Therefore, the simplified RS model proposed in this paper is suitable for efficiently and accurately predicting the RS in LC sheet for circular steel tubular columns repaired by LC.本文研究了激光熔覆（LC）修复圆形钢管柱中残余应力（RS）的大小和分布。研究包括实验测试和数值模拟。在实验研究中，采用了熟悉的盲孔法进行了两次 RS 测量试验，并采用有限元法进行了数值热机械分析，以获得温度场和 RS 场。结果表明，LC 板及其周围区域存在残余拉应力。LC 片区域和 LC 片-基底边界附近的 RS 远远大于远离 LC 片的基底区域的 RS。此外，沿扫描方向液相沉积板的 RS 值大于垂直于扫描方向的 RS 值。不过，LC 片和基底的 RS 值都小于各自的屈服强度值。有限元分析模拟了修复圆形钢管柱的激光熔覆过程，分析得到的温度-时间-冷却曲线被用来建立一个理论模型，以预测 LC 板中的 RS。根据热机械理论，利用线性-指数两阶段冷却曲线，提出了一个简化的 RS 模型。通过比较实验结果和使用所提出的简化 RS 模型预测的理论结果，发现两者的结果非常吻合。因此，本文提出的简化 RS 模型适用于高效、准确地预测 LC 修复圆形钢管柱的 LC 板中的 RS。来源：复合材料力学仿真Composites FEM
