【新文速递】2024年8月31日固体力学SCI期刊最新文章
今日更新：Journal of the Mechanics and Physics of Solids 2 篇，Mechanics of Materials 1 篇，Thin-Walled Structures 1 篇Journal of the Mechanics and Physics of SolidsRecovering Mullins damage hyperelastic behaviour with physics augmented neural networksMartin Zlatić, Marko Čanađijadoi:10.1016/j.jmps.2024.105839 用物理增强神经网络恢复Mullins损伤超弹性行为The aim of this work is to develop a neural network for modelling incompressible hyperelastic behaviour with isotropic damage, the so-called Mullins effect. This is obtained through the use of feed-forward neural networks with special attention to the architecture of the network in order to fulfil several physical restrictions such as objectivity, polyconvexity, non-negativity, material symmetry and thermodynamic consistency. The result is a compact neural network with few parameters that is able to reconstruct the hyperelastic behaviour with Mullins-type damage. The network is trained with artificially generated plane stress data and even correctly captures the full 3D behaviour with much more complex loading conditions. The energy and stress responses are correctly captured, as well as the evolution of the damage. The resulting neural network can be seamlessly implemented in widely used simulation software. Implementation details are provided and all numerical examples are performed in Abaqus.这项工作的目的是开发一个神经网络来模拟具有各向同性损伤的不可压缩超弹性行为，即所谓的穆林斯效应。这是通过使用前馈神经网络获得的，特别注意网络的结构，以满足一些物理限制，如客观性、多凸性、非负性、材料对称性和热力学一致性。结果得到了一个具有较少参数的紧凑神经网络，能够重建具有mullins型损伤的超弹性行为。该网络使用人工生成的平面应力数据进行训练，甚至可以在更复杂的加载条件下正确捕获完整的3D行为。能量和应力响应被正确捕获，以及损伤的演变。所得到的神经网络可以在广泛使用的仿真软件中无缝实现。提供了实现细节，并在Abaqus中执行了所有数值示例。A generalized phase-field cohesive zone model (μPF-CZM) for fractureJian-Ying Wudoi:10.1016/j.jmps.2024.105841断裂的广义相场内聚区模型（μPF-CZM）In this work a generalized phase-field cohesive zone model (μPF-CZM) is proposed within the framework of the unified phase-field theory for brittle and cohesive fracture. With the introduction of an extra dissipation function for the crack driving force, in addition to the geometric function for the phase-field regularization and the degradation function for the constitutive relation, theoretical and application scopes of the original PF-CZM are broadened greatly. These characteristic functions are analytically determined from the conditions for the length scale insensitivity and a non-shrinking crack band in a universal, optimal and rationalized manner, for almost any specific traction–separation law. In particular, with an optimal geometric function, the crack irreversibility can be considered without affecting the target traction–separation softening law. Not only concave softening behavior but also high-order cohesive traction, both being limitations of the previous works, can be properly dealt with. The global fracture responses are insensitive not only to the phase-field length scale but also to the traction order parameter, though the crack bandwidth might be affected by both. Despite the loss of variational consistency in general cases, the resulting μPF-CZM is still thermodynamically consistent. Moreover, the existing numerical implementation can be adopted straightforwardly with minor modifications. Representative numerical examples are presented to validate the proposed μPF-CZM and to demonstrate its capabilities in capturing brittle and cohesive fracture with general softening behavior. The insensitivity to both the phase-field length scale and the traction order parameter is also sufficiently verified.本文在脆性和内聚断裂统一相场理论框架内提出了广义相场内聚区模型（μPF-CZM）。除了相场正则化的几何函数和构成关系的退化函数外，还引入了额外的裂纹驱动力耗散函数，从而大大拓宽了原始 PF-CZM 的理论和应用范围。这些特征函数是根据长度尺度不敏感性和无收缩裂缝带的条件，以通用、优化和合理化的方式分析确定的，几乎适用于任何特定的牵引分离定律。特别是，利用最优几何函数，可以在不影响目标牵引分离软化规律的情况下考虑裂纹不可逆问题。不仅凹面软化行为，而且高阶内聚牵引力也能得到适当处理，而这两种行为都是以前工作的局限。全局断裂响应不仅对相场长度尺度不敏感，而且对牵引阶次参数也不敏感，尽管裂纹带宽可能会受到两者的影响。尽管在一般情况下失去了变分一致性，但所得到的 μPF-CZM 在热力学上仍然是一致的。此外，现有的数值实现方法只需稍加修改即可直接采用。为了验证所提出的 μPF-CZM 并证明其在捕捉具有一般软化行为的脆性和内聚断裂方面的能力，我们给出了具有代表性的数值示例。相场长度尺度和牵引阶参数的不敏感性也得到了充分验证。Mechanics of MaterialsCompression behavior of 316L diamond lattice structures fabricated via additive manufacturing with variable cell sizesJiaxi Zhao, Zulei Liang, Zhonggang Sundoi:10.1016/j.mechmat.2024.105135增材制造316L不同尺寸金刚石晶格结构的压缩性能The unit size effect of 316L diamond lattice structures was systematically investigated through experiments, theory, and simulations. Experimental tests demonstrated that reducing the cell size to 5 mm and 2.5 mm enhances the load carrying capacity and energy absorption of the structures. Additionally, analytical solutions were developed to acceptably estimate the elastic modulus and yield strength of diamond lattice structures. Finite element simulations, incorporating elastic, plastic, and ductile damage models, were utilized to depict the entire deformation evolution at different strain levels. These simulations were found to be precisely consistent with experimental observations. The results confirmed a transition from non-uniform deformation to uniform large-scale plastic deformation. This transition is attributed to either locally fractured struts caused by longer struts in structures with large cell sizes or largely deformed, non-ruptured short beams in structures with smaller cell sizes. Comparisons with previous reports indicated that the current structures with a cell size of 2.5 mm exhibit outstanding mechanical performance, making them desirable candidates for engineering applications.通过实验、理论和模拟等方法系统地研究了316L金刚石晶格结构的单位尺寸效应。实验结果表明，将微孔尺寸减小到5 mm和2.5 mm可以提高结构的承载能力和能量吸收能力。此外，还开发了可接受的分析解来估计金刚石晶格结构的弹性模量和屈服强度。结合弹性、塑性和延性损伤模型的有限元模拟用于描述不同应变水平下的整个变形演变过程。这些模拟结果与实验观察结果完全一致。结果证实了从非均匀变形到均匀大尺度塑性变形的转变。这种转变要么是由于大单元尺寸结构中较长的支柱局部断裂，要么是由于较小单元尺寸结构中较大变形但未破裂的短梁。与先前的报告比较表明，目前电池尺寸为2.5 mm的结构具有出色的机械性能，使其成为工程应用的理想候选者。Thin-Walled StructuresDynamic response analysis of cylindrical lithium-ion battery under impact loadings: A theoretical studyZi-xuan Huang, Xin-chun Zhang, Li-qiang An, Li-xiang Rao, Li-rong Gu, Chun-yan Lidoi:10.1016/j.tws.2024.112385冲击载荷下圆柱形锂离子电池动态响应分析的理论研究The prediction of serious deformation for lithium-ion batteries (LIBs) under impact loadings becomes an important challenge for engineering application. In this paper, a theoretical model is developed to investigate the dynamic responses of cylindrical LIBs based on the membrane factor method. The cylindrical LIB is simplified as double-layer structure consisting of the casing and jellyroll. The plastic yield criterion is established by utilizing tensile yield strengths and the corresponding membrane factor fn is defined. The dynamic responses of the cell under radial impact loading are explored. The accuracy of this method is verified by the corresponding finite element (FE) results. In addition, a comprehensive quantitative analysis of the governing factors of fn is conducted under different boundary conditions. Using the theoretical model, the response characteristics of the cell under different initial velocities and masses are investigated. The approximate equation for the variation of the maximum deflection with initial velocity and the saturation impact time are presented. The tendency of the deformation changing with size and tensile properties of the cell is obtained. These researches will provide technical support for the failure prediction and structural safety design of cylindrical cells.预测锂离子电池（LIB）在冲击载荷下的严重变形是工程应用中的一项重要挑战。本文基于膜因子法建立了一个理论模型来研究圆柱形锂离子电池的动态响应。圆柱形 LIB 被简化为由外壳和胶卷组成的双层结构。利用拉伸屈服强度建立了塑性屈服准则，并定义了相应的膜因子 fn。探讨了电池在径向冲击载荷下的动态响应。相应的有限元（FE）结果验证了该方法的准确性。此外，还在不同边界条件下对 fn 的控制因子进行了全面的定量分析。利用理论模型，研究了电池在不同初始速度和质量下的响应特性。给出了最大挠度随初速度和饱和冲击时间变化的近似方程。还得出了变形随电池尺寸和拉伸特性变化的趋势。这些研究将为圆柱形电池的失效预测和结构安全设计提供技术支持。来源：复合材料力学仿真Composites FEM
