【新文速递】2024年2月7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 2 篇，International Journal of Plasticity 2 篇，Thin-Walled Structures 1 篇International Journal of Solids and StructuresCrystal plasticity model for describing the work hardening of A5052-O sheets subjected to various loading pathsKengo Yoshidadoi:10.1016/j.ijsolstr.2024.112697用于描述不同加载路径下 A5052-O 板材加工硬化的晶体塑性模型The Bauschinger effect, which refers to softening after strain reversal, significantly affects the springback simulation of stamped sheet metals. Therefore, a constitutive model that can describe this effect is required to perform accurate springback simulations. This study developed a crystal plasticity model that accurately reproduces the Bauschinger and cross effects of aluminum alloy sheets. The model is based on saturation-type equations representing the evolution of slip resistances. In addition to incorporating the work hardening of slip resistance, softening after strain reversal is incorporated. Furthermore, in the model, latent hardening increases when the slip system is inactive, whereas its evolution is suppressed when the system is activated. This formulation facilitates the reproduction of the enhanced re-yield stress followed by a reduced work-hardening rate for orthogonal loading. The simulated stress–strain curves are compared with the experimental results for an A5052-O sheet. It is shown that the proposed model accurately reproduces the reverse and orthogonal loading behaviors of the A5052-O sheet. Furthermore, the influence of the formulation of slip resistance on the predicted R value in the uniaxial tension is examined.Bauschinger 效应是指应变反转后的软化，它对冲压薄板金属的回弹模拟有很大影响。因此，要进行精确的回弹模拟，需要一个能描述这种效应的构成模型。本研究开发了一种晶体塑性模型，可精确再现铝合金板材的鲍辛格效应和交叉效应。该模型基于表示滑移阻力演变的饱和型方程。除了包含滑移阻力的加工硬化外，还包含应变反转后的软化。此外，在该模型中，当滑移系统处于非活动状态时，潜伏硬化会增加，而当系统被激活时，其演变会被抑制。这种计算方法有助于再现正交加载时增强的再屈服应力和降低的加工硬化率。模拟的应力-应变曲线与 A5052-O 板材的实验结果进行了比较。结果表明，所提出的模型准确地再现了 A5052-O 板材的反向和正交加载行为。此外，还研究了单轴拉伸时滑移阻力配方对预测 R 值的影响。Journal of the Mechanics and Physics of SolidsA multiscale viscoelastic fiber dispersion model for strain rate-dependent behavior of planar fibrous tissuesKewei Li, Gerhard A. Holzapfeldoi:10.1016/j.jmps.2024.105572平面纤维组织应变率相关行为的多尺度粘弹性纤维分散模型Recently, we introduced an efficient discrete fiber dispersion model for characterizing the mechanical behavior of soft fibrous tissues, and we also extended that model to consider microscale collagen fiber recruitment, softening and damage. However, the viscous behavior of collagen fibers were not considered in that study. The goal of this study is to further extend the discrete fiber dispersion model to consider both elastic and viscous behavior of collagen fibers and ground substance such that the strain rate-dependent behavior of soft fibrous tissues can be characterized. We first reformulated the 3D discrete fiber dispersion model to a 2D version for tissues with planar fiber dispersion. Then, we introduced viscous parts to the model by adding Maxwell elements to the elastic parts of the strain–energy function. We implemented the proposed model in a finite element program and illustrated it with three numerical examples. The computational solutions of the first two examples agree well with our previous published results. In the last example, we characterized the rate-dependent behavior of aortic valve tissue with the proposed model. In conclusion, the proposed model is capable of characterizing the viscoelastic behavior of collagen fibers and ground substance. Future studies with patient-specific boundary conditions are necessary to verify this method.最近，我们引入了一种高效的离散纤维分散模型来描述软纤维组织的机械行为，并将该模型扩展到考虑微尺度胶原纤维的招募、软化和损伤。然而，该研究并未考虑胶原纤维的粘性行为。本研究的目标是进一步扩展离散纤维分散模型，以考虑胶原纤维和磨碎物质的弹性和粘性行为，从而描述软纤维组织随应变速率变化的行为。我们首先将三维离散纤维弥散模型重新制定为平面纤维弥散组织的二维版本。然后，我们在应变能函数的弹性部分添加了麦克斯韦元素，从而为模型引入了粘性部分。我们在有限元程序中实现了提议的模型，并用三个数值示例进行了说明。前两个例子的计算结果与我们之前公布的结果非常吻合。在最后一个例子中，我们用所提出的模型描述了主动脉瓣组织随速率变化的行为。总之，所提出的模型能够描述胶原纤维和基底物质的粘弹性行为。未来有必要使用患者特定的边界条件进行研究，以验证这种方法。Viscoelastic mechanics of two-dimensional granular latticesSrinivas Selvaraju, Shailendra P. Joshi, Nikhil Karanjgaokardoi:10.1016/j.jmps.2024.105574二维颗粒晶格的粘弹力学We study the rate-dependent mechanics of viscoelastic granular packings. Using a two-dimensional, square lattice of particles as a motif mimicking nominally mono-disperse granular packings, we perform a suite of finite element simulations under rate-dependent uniaxial compaction followed by unloading. The focus is on understanding the macroscopic force–displacement relations and the porosity evolution as a function of the viscoelastic relaxation parameters. For the constituent parameters considered here, the force–displacement relations show a two-stage power-law behavior, which is associated with the relative contributions of viscous dissipation and elastic effects at a particular loading rate. For a given loading rate, the nonlinearity of the porosity evolution depends on the constituent parameters and is found to be captured well by a simple analytical model. The heterogeneity of stresses during the compaction and recovery phases provide insights into the emergent complex micromechanics in simple granular motifs. Upon unloading, particles may experience transient tensile pressures, which could have implications on their failure.我们研究了粘弹性颗粒填料随速率变化的力学特性。我们使用二维方形颗粒晶格作为模拟名义上单分散粒状填料的图案，在随速率变化的单轴压实和卸载条件下进行了一系列有限元模拟。重点是理解宏观力-位移关系以及粘弹性松弛参数作用下的孔隙率演变。对于本文所考虑的组成参数，力-位移关系显示出两阶段幂律行为，这与特定加载速率下粘滞耗散和弹性效应的相对贡献有关。在给定的加载速率下，孔隙率演变的非线性取决于组成参数，简单的分析模型可以很好地捕捉到这种非线性。压实和恢复阶段的应力异质性为简单颗粒图案中出现的复杂微观力学提供了启示。在卸载时，颗粒可能会经历瞬时拉伸压力，这可能会对其失效产生影响。International Journal of PlasticityHydride-enhanced strain localization in zirconium alloy: a study by crystal plasticity finite element methodX.D. Zan, X. Guo, G.J. Wengdoi:10.1016/j.ijplas.2024.103911 锆合金中的氢化物强化应变定位：晶体塑性有限元法研究Hydride precipitation in zirconium (Zr) alloys leads to the deterioration of mechanical properties in key components of nuclear reactors. However, the underlying mechanisms governing the failure initiation of hydrogenated Zr alloys remain incompletely understood. This study focuses on investigating the effects of δ-phase hydride precipitation on the local deformation behavior of Zr alloys. A crystal plasticity finite element method is used to simulate micropillar compression tests of single-crystal samples and macroscale tensile tests of polycrystalline samples. Our results reveal that in the case of micropillar B containing δ-hydride (where the hydride is oriented at 45° from the loading direction), the shear along the hydride–matrix interface and the misfit strain induced by hydride precipitation synergistically contribute to strain localization of Zr alloys. However, for micropillar P containing δ-hydride (where the hydride is parallel to the loading direction), the introduction of hydrides does not enhance the strain localization. Instead, it impedes the local prismatic slip. On the other hand, examination of polycrystalline samples through simulations indicates that hydrides enhance the strain localization of Zr alloys. This effect arises from several mechanisms: shear stress along hybrid–matrix interface, promoting plastic slip in the direction close to this interface; hydride-induced hindrance to certain slip bands, leading to non-uniform local deformation; and misfit strains induced by hydride precipitation, contributing to localized deformation around the hydrides.锆（Zr）合金中的氢化物析出会导致核反应堆关键部件的机械性能下降。然而，人们对氢化锆合金引发失效的基本机制仍不甚了解。本研究的重点是研究δ相氢化物析出对 Zr 合金局部变形行为的影响。采用晶体塑性有限元法模拟单晶样品的微柱压缩试验和多晶样品的宏观拉伸试验。我们的研究结果表明，对于含有δ-氢化物的微晶柱 B（氢化物的方向与加载方向成 45°），沿氢化物-基体界面的剪切力和氢化物析出引起的错配应变协同促进了锆合金的应变定位。然而，对于含有δ-氢化物（氢化物与加载方向平行）的微柱 P，氢化物的引入并不会增强应变定位。相反，它阻碍了局部棱柱滑移。另一方面，通过模拟对多晶样品的研究表明，氢化物增强了锆合金的应变局部化。这种效应产生于以下几种机制：沿混合基体-基体界面的剪应力，促进了靠近该界面方向的塑性滑移；氢化物引起的对某些滑移带的阻碍，导致了不均匀的局部变形；氢化物析出引起的错配应变，导致了氢化物周围的局部变形。Modeling of creep in nickel-based superalloy based on microtwinning mechanismJingyu Zhang, Ying Liu, Yangyang Cheng, Hao Wang, Aixue Sha, Huiling Duandoi:10.1016/j.ijplas.2024.103916基于微捻机制的镍基超合金蠕变建模Microtwinning is the dominant creep deformation mechanism of nickel-based superalloy in certain temperature and stress conditions. This study proposes a novel temperature-dependent creep constitutive model based on microtwinning mechanism, which includes the glide of 1/6<112> partial dislocations and atomic diffusion in γ′ precipitates. Both microtwinning and anti-phase boundary shearing mechanisms are considered in the crystal plasticity finite element model. The numerical steady-state creep rates of single crystal and polycrystalline nickel-based superalloys agree with the experimental data at different holding stresses and temperatures. Microtwinning is activated at a lower stress than that of anti-phase boundary shearing. The competition between dislocation slip and atomic diffusion is analyzed, and the dominant mechanism is revealed for the microtwinning dominated creep at different holding stresses and temperatures. This study deepens the understanding of microtwinning-based creep deformation and could provide an effective model for the creep of nickel-based superalloy.微孪晶是镍基超合金在特定温度和应力条件下的主要蠕变变形机制。本研究基于微孪晶机制提出了一种新的随温度变化的蠕变构成模型，其中包括 1/6<112> 部分位错的滑移和 γ′ 沉淀中的原子扩散。晶体塑性有限元模型考虑了微孪晶和反相界剪切机制。在不同的保持应力和温度下，单晶和多晶镍基超合金的数值稳态蠕变速率与实验数据一致。在比反相界剪切应力更低的应力下，微缠结被激活。分析了位错滑移和原子扩散之间的竞争，揭示了不同保持应力和温度下微扭转主导蠕变的主要机制。这项研究加深了人们对基于微孪晶的蠕变变形的理解，可为镍基超合金的蠕变提供一个有效的模型。Thin-Walled StructuresA slice model for thermoelastic analysis of porous functionally graded material sandwich beams with temperature-dependent material propertiesZhong Zhang, Ying Sun, Xiaojian Cao, Jiajing Xu, Lu Yaodoi:10.1016/j.tws.2024.111700多孔功能梯度材料夹层梁热弹性分析切片模型（材料特性随温度变化Porosity usually occurs in functionally graded materials (FGMs) during the fabrication process. Its effects on the thermomechanical behaviors of FGM structures are worth studying. In this work, heat transfer and thermoelastic behaviors of porous FGM sandwich beams with temperature-dependent material properties are examined. The effective material properties are approximately estimated by the modified Voigt mixture rule. Because of the continuously varied material properties across the thickness direction, it is impractical to seek exact solutions for the beam. By proposing a slice model in which the face and core layers are divided into numerous thin slices, the material properties of each slice can be treated as uniform. Based on the model, the through-thickness temperature distribution is first obtained by using an iteration algorithm. Then the two-dimensional (2-D) thermoelasticity equations are analytically solved by using the state space method and Fourier series expansion method. The correctness of the proposed model is checked through comparison with results reported in previous works. The effects of some key factors such as the temperature dependence of material properties, volume fraction, and porosity on the thermomechanical behaviors of the beam are comprehensively studied. It is shown that with the increase of porosity, the thermal resistance capacity of the beam is enhanced yet the bending stiffness is weakened.孔隙通常出现在功能分级材料（FGM）的制造过程中。它对 FGM 结构的热力学行为的影响值得研究。本文研究了多孔 FGM 夹层梁的传热和热弹性行为，其材料特性与温度有关。有效材料特性是通过改进的 Voigt 混合规则近似估算的。由于材料特性在厚度方向上不断变化，因此寻求梁的精确解是不切实际的。通过提出一种切片模型，将面层和芯层分成许多薄片，可以将每个薄片的材料特性视为均匀的。在该模型的基础上，首先使用迭代算法获得厚度温度分布。然后利用状态空间法和傅里叶级数展开法对二维热弹性方程进行解析求解。通过与前人研究成果的对比，检验了所提模型的正确性。全面研究了一些关键因素，如材料特性、体积分数和孔隙率的温度依赖性对梁热力学行为的影响。结果表明，随着孔隙率的增加，梁的热阻能力增强，但弯曲刚度减弱。来源：复合材料力学仿真Composites FEM