【新文速递】2024年1月24日固体力学SCI期刊最新文章

1天前浏览45

今日更新：International Journal of Solids and Structures 1 篇，International Journal of Plasticity 1 篇，Thin-Walled Structures 4 篇

International Journal of Solids and Structures

Voltage-controlled non-axisymmetric vibrations of soft electro-active tubes with strain-stiffening effect

Fangzhou Zhu, Bin Wu, Michel Destrade, Huiming Wang, Ronghao Bao, Weiqiu Chen

doi:10.1016/j.ijsolstr.2024.112671

具有应变加劲效应的软电活性管的压控非轴对称振动

Material properties of soft electro-active (SEA) structures are significantly sensitive to external electro-mechanical biasing fields (such as pre-stretch and electric stimuli), which generate remarkable knock-on effects on their dynamic characteristics. In this work, we analyze the electrostatically tunable non-axisymmetric vibrations of an incompressible SEA cylindrical tube under the combination of a radially applied electric voltage and an axial pre-stretch. Following the theory of nonlinear electro-elasticity and the associated linearized theory for superimposed perturbations, we derive the nonlinear static response of the SEA tube to the inhomogeneous biasing fields for the Gent ideal dielectric model. Using the State Space Method, we efficiently obtain the frequency equations for voltage-controlled small-amplitude three-dimensional non-axisymmetric vibrations, covering a wide range of behaviors, from the purely radial breathing mode to torsional modes, axisymmetric longitudinal modes, and prismatic diffuse modes. We also perform an exhaustive numerical analysis to validate the proposed approach compared with the conventional displacement method, as well as to elucidate the influences of the applied voltage, axial pre-stretch, and strain-stiffening effect on the nonlinear static response and vibration behaviors of the SEA tube. The present study clearly indicates that manipulating electro-mechanical biasing fields is a feasible way to tune the small-amplitude vibration characteristics of an SEA tube. The results should benefit experimental work on, and design of, voltage-controlled resonant devices made of SEA tubes.

软电活性(SEA)结构的材料性能对外部机电偏置场(如预拉伸和电刺激)非常敏感，这对其动态特性产生了显著的连锁效应。在这项工作中，我们分析了不可压缩SEA圆柱管在径向施加电压和轴向预拉伸的组合下的静电可调非轴对称振动。根据非线性电弹性理论和相关的叠加扰动线性化理论，导出了根特理想介质模型下SEA管对非均匀偏置场的非线性静态响应。利用状态空间方法，我们有效地获得了电压控制的小幅度三维非轴对称振动的频率方程，涵盖了从纯径向呼吸模式到扭转模式、轴对称纵向模式和棱镜扩散模式的广泛行为。与传统的位移法相比，我们还进行了详尽的数值分析来验证所提出的方法，并阐明了施加电压、轴向预拉伸和应变加筋效应对SEA管的非线性静态响应和振动行为的影响。本研究清楚地表明，操纵机电偏置场是调节SEA管小振幅振动特性的可行方法。研究结果对SEA管压控谐振器件的实验工作和设计有一定的参考价值。

International Journal of Plasticity

A continuum scale chemo-mechanical model for multi-trap hydrogen transport in deformed polycrystalline metals

Jinheung Park, Geonjin Shin, Hye-Jin Kim, Kijung Kim, Yoon Seung Chae, Seok Su Sohn, Myoung-Gyu Lee

doi:10.1016/j.ijplas.2024.103890

变形多晶金属中多阱氢输运的连续尺度化学-力学模型

This study presents a coupled multi-trap hydrogen diffusion and crystal plasticity model within a thermodynamically consistent framework. The developed modeling scheme incorporates the hydrogen-enhanced localized plasticity (HELP) and hydrogen-enhanced strain-induced plasticity (HESIV) based on thermodynamic considerations. The theoretical formulations are implemented in the finite element method, which considers the concentration- and chemical potential-based balance equations. The validity of the coupled model is established through preliminary single element simulations under isothermal conditions, showcasing the predictability of evolution of hydrogen concentration and occupancies in the deformed microstructure of polycrystalline metal. Then, the developed computational approach is applied to two materials exhibiting hydrogen-induced hardening and softening behaviors in accordance with the HELP mechanism and vacancy-hydrogen complex (VaH) formation under isothermal condition. The model successfully reproduces the change of mechanical behavior induced by hydrogen in both materials. The effects of hydrogen diffusivity and the binding energy of defects on hydrogen transport are also investigated. Furthermore, the sensitivity of hydrogen diffusion to different trapping mechanisms, local equilibrium trapping and kinetics trapping, is examined. The proposed modeling framework can be applied to new material design strategies for developing metals resistant to hydrogen embrittlement.

本研究在热力学一致的框架内提出了一个耦合的多阱氢扩散和晶体塑性模型。所开发的模型方案结合了基于热力学考虑的氢增强局部塑性(HELP)和氢增强应变诱导塑性(HESIV)。理论公式在有限元法中实现，考虑了基于浓度和化学势的平衡方程。通过在等温条件下的初步单元素模拟，验证了耦合模型的有效性，显示了多晶金属变形微观结构中氢浓度和占比的演化可预测性。然后，将所建立的计算方法应用于两种具有氢致硬化和软化行为的材料，根据HELP机制和在等温条件下形成的空位-氢络合物(VaH)。该模型成功地再现了氢在两种材料中引起的力学行为变化。研究了氢扩散系数和缺陷结合能对氢输运的影响。此外，还研究了氢扩散对不同捕获机制(局部平衡捕获和动力学捕获)的敏感性。所提出的建模框架可以应用于开发抗氢脆金属的新材料设计策略。

Thin-Walled Structures

Laser cleaning assisted wire arc additive manufacturing of aluminum alloy thin-wall through synchronous wire-powder deposition

Yunfei Meng, Zeyu Li, Ming Gao, Hui Chen, Xu Wu, Qianxi Yu

doi:10.1016/j.tws.2024.111622

激光清洗辅助同步线粉沉积铝合金薄壁线弧增材制造

Due to the interference of ambient wind on arc burning and droplet transfer, wire arc additive manufacturing (WAAM) of aluminum alloy in field environment is hindered. The gas-slag joint protection by synchronous feeding of AlSi5 wire and mixed powder of 90Mg-5TiO2-5NaF (wt.%) was introduced. It was found the wind resistance for the stable deposition of thin-wall could be improved from 1.5 to 3.5 m/s. The added Mg benefited to refine the grain size by 21% and promote the formation of Mg2Si, which improved the mechanical properties by induced solid solution-precipitation strengthening effects. Furthermore, with the assistance of laser cleaning, the porosity of thin-wall deposited at ambient wind speed of 3.5 m/s was reduced from 54.9% to 28%. These improvements increased the ultimate tensile strength and elongation to 166 MPa and 3.7%, reaching 98.2% and 31% of the WAAM at indoor windless environment respectively.

由于环境风对电弧燃烧和熔滴传递的干扰，阻碍了现场环境下铝合金丝弧增材制造。介绍了用90Mg-5TiO2-5NaF (wt.%)混合粉末同步进料AlSi5丝保护气渣接头的方法。结果表明，薄壁稳定沉积的抗风能力可由1.5 m/s提高到3.5 m/s。Mg的加入使晶粒细化21%，促进Mg2Si的形成，通过诱导固溶析出强化效应改善了合金的力学性能。此外，在激光清洗的帮助下，在3.5 m/s环境风速下沉积的薄壁孔隙率从54.9%降低到28%。这些改进使材料的极限抗拉强度和伸长率分别达到166 MPa和3.7%，分别达到室内无风环境下WAAM的98.2%和31%。

A novel method to design gradient porous structures with conformal density

Bin Liu, Xiaofeng Wei, Wei Cao, Ping Lu, Xiaofeng Wang

doi:10.1016/j.tws.2024.111623

一种设计保形密度梯度多孔结构的新方法

This work introduces a rapid modeling method for gradient porous structures with conformal density, aiming to address the challenges of transitional variation of porosity, and control of complex gradient variations in multiple directions. In comparison to other methods, this approach overcomes the limitations associated with coordinate systems and shape functions when designing complex gradient variations in multiple directions while achieving density variation with shape under different gradients. The method involves mapping the volumetric distance field to a density field using control functions. By adhering to the constraints of the density field, it employs a weighted random sampling method to attain gradient sites with shape-adaptive distribution. Voronoi polyhedron are then constructed based on these sites, and smooth Voronoi struts are generated using strut distance fields and improved Boolean operations. The boundary adaptation of the porous structure is subsequently achieved based on the volumetric distance field. By establishing the relationship between density and volumetric distance field values, the study illustrates the similarity between density variation in the structure and gradient variations in the control function, indicating the controllability of density variation with shape. Furthermore, the method enables the integration design of structural shape and mechanical properties through adjustments to the number of sites, radius size of struts, and gradient control functions. Finally, the method was validated through numerical simulation and experiments, demonstrating its controllability and effectiveness in generating random porous structures with conformal density gradients, providing important theoretical and practical support for research and application in related fields.

本文介绍了一种具有保形密度的梯度多孔结构的快速建模方法，旨在解决孔隙度过渡变化和多方向复杂梯度变化控制的挑战。与其他方法相比，该方法克服了设计多方向复杂梯度变化时坐标系和形状函数的局限性，同时实现了不同梯度下密度随形状的变化。该方法包括使用控制函数将体积距离场映射到密度场。该算法遵循密度场的约束，采用加权随机抽样的方法获得具有形状自适应分布的梯度点。然后基于这些位点构建Voronoi多面体，并使用支柱距离场和改进的布尔运算生成平滑的Voronoi支柱。随后基于体积距离场实现了多孔结构的边界自适应。通过建立密度与体积距离场值之间的关系，说明了结构上的密度变化与控制函数上的梯度变化具有相似性，说明了密度变化对形状的可控性。此外，该方法还可以通过调整支杆的位置数量、半径大小和梯度控制函数，实现结构形状和力学性能的一体化设计。最后，通过数值模拟和实验验证了该方法的可控性和有效性，为相关领域的研究和应用提供了重要的理论和实践支持。

Experimental and numerical study of corrugated steel-plain concrete composite structures under contact explosions

Siyuan Yu, Guokai Zhang, Zhen Wang, Ju Liu, Shuxin Deng, Xianzhao Song, Mingyang Wang

doi:10.1016/j.tws.2024.111624

接触爆炸作用下波纹钢-素混凝土组合结构的试验与数值研究

This paper investigates the dynamic response and blast resistance of corrugated steel-plain concrete (CSPC) composite structures subjected to contact blast. A series of explosive tests were conducted to investigate the acceleration, deformation, and damage patterns of CSPC plates under varying blast loads and arrangements of shear connectors, and these findings were compared with reinforced concrete (RC) plates. The results suggested that CSPC plates exhibited superior ductility and blast resistance, and effectively mitigated concrete collapse. The CSPC slab primarily underwent elastic deformation when the TNT charge was small, with the rebound deformation of the concrete and steel plates acting as a significant mode of energy dissipation. As for larger TNT charges, the maximum deformation of the plate progressively increased, especially when exceeding 0.3 kg, the deformation rebound ratio decreased significantly, and the plastic deformation increased. For further increased explosive loads, the concrete and steel plates exhibited a pronounced strain rate effect with a slowed growth rate of deformation. By examining different configurations of shear connectors, it was discovered that the adhesive strength between concrete and steel plates was closely related to the energy dissipation mode, and the elastic recovery capability and deformation resistance of the CSPC structure significantly deteriorated when the shear connectors were shorter, sparser or thinner. A numerical model based on LS-DYNA was designed to further analyze the blast resistance characteristics of CSPC plates. An engineering collapse coefficient Kz was established to predict the failure level of the CSPC plates. This paper provides useful insights for the optimal design and damage assessment of CSPC composite structures.

研究了波纹钢-素混凝土组合结构在接触爆破作用下的动力响应和抗爆性能。通过一系列爆炸试验，研究了CSPC板在不同爆炸荷载和剪切连接件布置下的加速度、变形和损伤模式，并将这些结果与钢筋混凝土(RC)板进行了比较。结果表明，CSPC板具有良好的延性和抗震性，能有效地减缓混凝土的倒塌。当TNT装药较小时，CSPC板主要发生弹性变形，混凝土和钢板的回弹变形是重要的耗能方式。较大TNT装药时，板的最大变形逐渐增大，特别是超过0.3 kg时，变形回弹比明显减小，塑性变形增大。当爆炸荷载进一步增大时，混凝土和钢板表现出明显的应变速率效应，变形增长速度减慢。通过对不同剪力连接件配置的考察，发现混凝土与钢板之间的粘接强度与耗能方式密切相关，剪力连接件越短、越稀疏、越薄，CSPC结构的弹性恢复能力和抗变形能力明显下降。设计了基于LS-DYNA的数值模型，进一步分析了CSPC板的耐爆特性。建立了CSPC板的工程破坏系数Kz来预测CSPC板的破坏程度。本文为CSPC复合材料结构的优化设计和损伤评估提供了有益的见解。

Comparison of free vibration behaviors for simply supported and clamped T-shaped thin plate resting on Winkler elastic foundation

Hao-Jie Jiang, Qing-Zhao Guo, Xiao-Gui Wang, Ning-Hua Gao

doi:10.1016/j.tws.2024.111621

温克勒弹性基础上简支与夹紧t型薄板自由振动特性比较

The analysis of free vibration problems for thin plates is essential for the design of various structural systems. However, it is difficult to find analytical solutions due to the complexity of mathematical computing. Based on the symplectic superposition method, the T-shaped thin plate on the Winkler elastic foundation is divided into four sub-plates and are solved by using the symplectic eigen expansion method, and the modes and frequencies are studied. The method begins directly with the fundamental equations and undergoes a rigorous mathematical derivation without assuming the form of the solution beforehand. This approach helps circumvent the drawbacks associated with traditional semi-inverse solution methods. In addition, the theoretical calculation model and finite element analysis model of T-shaped thin plates on elastic foundation are established by using Mathematic software and ABAQUS software in present paper. It proves that the symplectic superposition method converges very fast and has a good consistency with the finite element simulation results. Results show that the boundary condition, foundation stiffness and aspect ratio have great influences on vibration frequency and mode shape for T-shaped structures.

薄板自由振动问题的分析对各种结构体系的设计至关重要。然而，由于数学计算的复杂性，很难找到解析解。基于辛叠加法，将温克勒弹性基础上的t型薄板划分为4个子板，采用辛本征展开法进行求解，研究了其模态和频率。该方法直接从基本方程开始，经过严格的数学推导，而无需事先假设解的形式。这种方法有助于克服与传统半逆解方法相关的缺点。此外，本文还利用数学软件和ABAQUS软件建立了弹性基础上t型薄板的理论计算模型和有限元分析模型。结果表明，辛叠加法收敛速度快，与有限元仿真结果有较好的一致性。结果表明，边界条件、基础刚度和展弦比对t型结构的振动频率和振型有较大影响。

来源：复合材料力学仿真Composites FEM

【新文速递】2024年1月11日固体力学SCI期刊最新文章

今日更新：International Journal of Solids and Structures 1 篇，Journal of the Mechanics and Physics of Solids 1 篇，Mechanics of Materials 1 篇，International Journal of Plasticity 2 篇，Thin-Walled Structures 1 篇International Journal of Solids and StructuresCorrelation between surface-to-volume ratio of the particle shape and elastic properties of the particulate compositesPascal Alexander Happ, Romana Piatdoi:10.1016/j.ijsolstr.2024.112658颗粒形状的表面体积比与颗粒复合材料弹性特性之间的相关性This work is motivated by real-world particle shapes, observed using a scanning electron microscopy. The focus of the presented studies was to understand the effects of the particle shapes on the effective elastic properties of the two-phase composites. For this, particles with polyhedral, undulated and other shapes were numerically modeled using analytical functions. Creation of some shapes, like polyhedral, are known from the literature but Laplace’s spherical harmonics, as well as the Goursat’s surface and some others, were used for the first time to create novel particle shapes. Elastic properties of the composites with different particle shapes were calculated using the finite element analysis. The obtained results show good agreement with mean-field homogenization methods such like Mori-Tanaka and Lielens as well as other numerical results available in the literature. Further, the dependence of the effective Young’s moduli of the composite on the shape and the corresponding surface-to-volume ratio of the particles was studied. It was observed that the effective Young’s moduli increase with the surface-to-volume ratio of the particles in the case where particles are stiffer in comparison to the matrix. It was also remarked that, in the case of particles of similar shapes, the particle surface-to-volume ratio and the effective Young’s moduli differ significantly with the surface curvature and the edge sharpness of the particles.这项工作的动力来自于使用扫描电子显微镜观察到的真实颗粒形状。本研究的重点是了解颗粒形状对两相复合材料有效弹性特性的影响。为此，使用分析函数对多面体、波状和其他形状的颗粒进行了数值建模。一些形状（如多面体）的创建已从文献中获知，但拉普拉斯球面谐波以及 Goursat 曲面和其他一些形状是首次用于创建新颖的颗粒形状。使用有限元分析计算了不同颗粒形状的复合材料的弹性特性。所得结果与 Mori-Tanaka 和 Lielens 等平均场均质化方法以及文献中的其他数值结果显示出良好的一致性。此外，还研究了复合材料的有效杨氏模量与颗粒形状和相应的表面体积比的关系。研究发现，在颗粒与基体相比更硬的情况下，有效杨氏模量随颗粒的表面体积比增加而增加。研究还注意到，在颗粒形状相似的情况下，颗粒表面体积比和有效杨氏模量随颗粒表面曲率和边缘锐度的变化而显著不同。Journal of the Mechanics and Physics of SolidsGrain boundary network plasticity: Reduced-order modeling of deformation-driven shear-coupled microstructure evolutionDaniel Bugas, Brandon Runnelsdoi:10.1016/j.jmps.2024.105541晶界网络塑性：变形驱动剪切耦合微结构演化的降阶建模Microstructural evolution in structural materials is known to occur in response to mechanical loading and can often accommodate substantial plastic deformation through the coupled motion of grain boundaries (GBs). This can produce desirable behavior, such as increased ductility, or undesirable behavior such as mechanically-induced coarsening. In this work a novel, multiscale model is developed for capturing the combined effect of plasticity mediated by multiple GBs simultaneously. This model is referred to as “grain boundary network plasticity.” The mathematical framework of graph theory is used to describe the microstructure connectedness, and the evolution of microstructure is represented as volume flow along the graph. By using the principle of minimum dissipation potential, which has previously been applied to grain boundary migration, a set of evolution equations are developed that transfer volume and eigendeformation along the graph edges in a physically consistent way. It is shown that higher-order geometric effects, such as the pinning effect of triple points, may be accounted for through the incorporation of a geometric hardening that causes geometry-induced GB stagnation. The result is a computationally efficient reduced order model that can be used to simulate the initial motion of grain boundaries in a polycrystal with parameters informed by atomistic simulations. The effectiveness of the model is demonstrated through comparison to multiple bicrystal atomistic simulations, as well as a select number of GB engineered and non-GB engineered data obtained from the literature. The effect of the network of shear-coupling grain boundaries is demonstrated through mechanical response tests and by examining the yield surfaces.众所周知，结构材料的微观结构演变是对机械负载的响应，通常可通过晶界（GB）的耦合运动产生大量塑性变形。这可能产生理想的行为，如增加延展性，也可能产生不理想的行为，如机械引起的粗化。本研究开发了一种新型多尺度模型，可同时捕捉多个 GB 介导的塑性综合效应。该模型被称为 "晶界网络塑性"。该模型采用图论的数学框架来描述微观结构的连通性，并将微观结构的演变表示为沿图的体积流。利用之前应用于晶界迁移的最小耗散势原理，建立了一组演化方程，以物理一致的方式沿图边传递体积和特征变形。研究表明，高阶几何效应（如三重点的针销效应）可以通过加入几何硬化来解释，几何硬化会导致几何诱导的 GB 停滞。结果是一个计算效率高的降阶模型，可用于模拟多晶体中晶界的初始运动，其参数由原子模拟提供。通过与多个双晶原子模拟以及从文献中获取的部分 GB 工程和非 GB 工程数据进行比较，证明了该模型的有效性。通过机械响应测试和屈服面检查，证明了剪切耦合晶界网络的效果。Mechanics of MaterialsConstitutive models for confined elastomeric layers: Effects of nonlinearity and compressibilitySida Hao, Rui Huang, Gregory J. Rodindoi:10.1016/j.mechmat.2024.104912约束弹性层的构造模型：非线性和可压缩性的影响Elastomers tend to undergo large deformations accompanied by small volumetric changes. For elastomeric layers sandwiched between rigid plates, large deformations can be significantly limited by the constraints imposed by the plates. Further, those constraints can be enhanced by material’s inability to undergo large volumetric changes. From this perspective, it is appropriate to examine the validity of constitutive models, in which an elastomer is treated as incompressible, for analysis of the confined layers. Here, this issue is addressed by considering the mechanical response of sandwiched elastomeric layers using three constitutive models. The first one, referred to as compressible neo-Hookean, is regarded as exact. The other two models are regarded as approximations. Of those two, the first one neglects nonlinearity and the second one neglects compressibility. Accordingly, the modeling errors associated with the former are treated as measures of importance of nonlinearity, and the modeling errors associated with the latter are treated as measures of importance of compressibility. The modeling errors are evaluated using the force–displacement curve and the mean stress at the layer center as the quantities of interest. Numerical results are presented for rubber and polydimethylsiloxane (PDMS), characterized by Poisson’s ratios ν=0.4999 and ν=0.49, respectively. It is shown that, even when the forces applied to the plates are large, considering nonlinearity is important for thick but not for thin layers. In contrast, considering compressibility is important for thin layers. The need for considering compressibility is further assessed by introducing a competition parameter, which reinforces the notion that compressibility is important for modeling PDMS layers and thin rubber layers.弹性体往往会发生较大的变形，同时伴随着较小的体积变化。对于夹在刚性板之间的弹性层来说，大变形可能会受到刚性板的严重限制。此外，由于材料无法发生大的体积变化，这些限制也会增强。从这一角度出发，研究将弹性体视为不可压缩的构成模型对分析约束层的有效性是合适的。在此，通过使用三种构成模型来考虑夹层弹性体层的机械响应，从而解决这一问题。第一个模型被称为可压缩新胡肯模型，是精确模型。其他两个模型被视为近似模型。在这两个模型中，第一个忽略了非线性，第二个忽略了可压缩性。因此，与前者相关的建模误差被视为非线性重要性的度量，与后者相关的建模误差被视为压缩性重要性的度量。使用力-位移曲线和层中心的平均应力作为相关量来评估建模误差。研究给出了橡胶和聚二甲基硅氧烷（PDMS）的数值结果，这两种材料的泊松比分别为 ν=0.4999 和 ν=0.49。结果表明，即使施加在板上的力很大，考虑非线性对厚层也很重要，但对薄层却不重要。相反，考虑可压缩性对薄层很重要。通过引入竞争参数，进一步评估了考虑可压缩性的必要性，从而加强了可压缩性对于 PDMS 层和薄橡胶层建模非常重要的观点。International Journal of PlasticityA continuum damage coupled unified viscoplastic model for simulating the mechanical behaviour of a ductile cast iron under isothermal low-cycle fatigue, fatigue-creep and creep loadingMichal Bartošák, Jakub Horváthdoi:10.1016/j.ijplas.2023.103868用于模拟球墨铸铁在等温低循环疲劳、疲劳-蠕变和蠕变载荷下机械性能的连续损伤耦合统一粘塑模型A novel continuum damage coupled unified viscoplastic model is used for simulating the stress–strain responses of SiMo 4.06 cast iron under Low-Cycle Fatigue (LCF), fatigue-creep and creep loading for temperatures up to 650 °C. The advanced constitutive model that is developed within the framework of the Chaboche model allows the simulation of various effects including strain rate sensitivity, cyclic hardening and softening, static recovery and strain range dependency. The hyperbolic sine flow rule and the static recovery of kinematic hardening rule are proposed in order to effectively simulate both stress relaxation and creep strains. The isotropic damage variable is introduced into the constitutive equations to represent the effects of material degradation. Three main damage mechanisms are considered: fatigue, creep and ductile damage. In addition, the model is further modified to take into account the progressive microdefects closure effect. Finally, the prediction capability of the proposed model is illustrated for the experimental data obtained from the various uniaxial material tests. A good correlation was achieved between the simulated and the experimental results.采用新颖的连续损伤耦合统一粘塑模型模拟 SiMo 4.06 铸铁在低循环疲劳 (LCF)、疲劳-蠕变和蠕变载荷下的应力-应变响应，温度最高可达 650 °C。在 Chaboche 模型框架内开发的高级构成模型可模拟各种效应，包括应变速率敏感性、循环硬化和软化、静态恢复和应变范围依赖性。为了有效模拟应力松弛和蠕变应变，提出了双曲正弦流动规则和运动硬化静态恢复规则。在构成方程中引入了各向同性损伤变量，以表示材料退化的影响。模型考虑了三种主要损伤机制：疲劳损伤、蠕变损伤和韧性损伤。此外，还进一步修改了模型，以考虑渐进式微缺陷闭合效应。最后，针对从各种单轴材料试验中获得的实验数据，说明了所提模型的预测能力。模拟结果和实验结果之间实现了良好的相关性。A computational mechanical constitutive modeling method based on thermally-activated microstructural evolution and strengthening mechanismsMingyu Lei, Guangpeng Sun, Guochun Yang, Bin Wendoi:10.1016/j.ijplas.2024.103881基于热激活微结构演化和强化机制的计算力学结构建模方法A mechanical constitutive relationship is the basis for the design and application of structural materials, and the establishment of a mechanical constitutive relationship generally relies on experimental data. Herein a computational mechanical constitutive modeling method is proposed, in which all required parameters possess unambiguous physical interpretations and/or can be obtained from accurate numerical simulations. With the inclusion of interaction between dislocations and crystal defects, the dislocation density and grain size evolution with strain for polycrystalline metallic materials are mathematically modeled, and the corresponding contribution to strength is analysed, further a computational mechanical constitutive relationship can be obtained. Its effectiveness is verified by comparing it with experimental stress-strain relationships for Cu, Al-Mg, and Cu-W alloys. This method might be a powerful tool for the design of structural materials with desirable mechanical properties.力学构成关系是结构材料设计和应用的基础，而力学构成关系的建立一般依赖于实验数据。本文提出了一种计算力学构成模型方法，其中所有必要参数都具有明确的物理解释和/或可从精确的数值模拟中获得。通过将位错与晶体缺陷之间的相互作用考虑在内，对多晶金属材料的位错密度和晶粒大小随应变的演变进行了数学建模，并分析了其对强度的相应贡献，从而进一步获得了计算力学组成关系。通过与铜、铝-镁和铜-钨合金的实验应力-应变关系进行比较，验证了该方法的有效性。这种方法可能是设计具有理想机械性能的结构材料的有力工具。Thin-Walled StructuresDeformation behaviors of defective aluminum honeycomb sandwich panels subjected to in-panel compressive loading: an experimental study with mirror-assisted multi-view DICKaiyu Zhu, Bing Pandoi:10.1016/j.tws.2024.111592缺陷铝蜂窝夹芯板在板内压缩载荷作用下的变形行为：利用镜像辅助多视角 DIC 进行的实验研究Honeycomb sandwich panels have been extensively utilized in the aerospace and automotive industries for their prominent advantages of energy absorption, high strength and tailorable anisotropic mechanical properties. Nevertheless, the common presence of local core-to-skin disbonding poses an urgent need to understand the mechanical behaviors of defective honeycomb sandwich panels. The present work investigates the deformation behaviors and evolutions of aluminum honeycomb sandwich panels with varying sizes of circular artificial core-to-skin disbonding defects using mirror-assisted multi-view digital image correlation (MV-DIC). Based on the 3D profiles and dual-surface deformation fields obtained with mirror-assisted MV-DIC, it is revealed that disbonding defects induced local surface undulations with severe local strain concentrations and determined the mode of gradual bending and buckling. Defects with a diameter below 20 mm induced minor local surface undulations and slight decreases in buckling load. When the diameters of defects reach 30 mm, extensive surface convex deformation occurs and the buckling load decreases by 23%. The results validate mirror-assisted MV-DIC as a cost-effective and practical technique for characterizing dual-surface 3D deformation of sheet composite materials and structures.蜂窝夹芯板具有能量吸收、高强度和可定制的各向异性机械性能等突出优势，已被广泛应用于航空航天和汽车行业。然而，由于普遍存在局部芯-皮脱粘现象，因此迫切需要了解有缺陷的蜂窝夹芯板的机械性能。本研究利用镜像辅助多视角数字图像相关（MV-DIC）技术，研究了存在不同大小的圆形人工芯-皮脱粘缺陷的铝蜂窝夹芯板的变形行为和演变过程。根据镜像辅助 MV-DIC 所获得的三维剖面和双表面变形场，可以发现脱粘缺陷会引起局部表面起伏，造成严重的局部应变集中，并决定了逐渐弯曲和屈曲的模式。直径小于 20 毫米的缺陷引起的局部表面起伏较小，屈曲载荷也略有下降。当缺陷直径达到 30 毫米时，会出现大面积的表面凹凸变形，屈曲载荷降低了 23%。这些结果验证了镜像辅助 MV-DIC 是表征片状复合材料和结构双表面三维变形的一种经济实用的技术。来源：复合材料力学仿真Composites FEM