【新文速递】2024年9月21日复合材料SCI期刊最新文章_ACT_Mechanical_Additive_Optical_System_振动_断裂_复合材料_化学_光学_航空_航天_汽车_电子_农业_裂纹_电场_理论_电机

【新文速递】2024年9月27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 SolidsCreasing instability of polydomain nematic elastomers in compressionAlireza Ahmadi, Neda Maghsoodidoi:10.1016/j.jmps.2024.105870压缩条件下多畴向列弹性体的增皱不稳定性Polydomain liquid crystalline (nematic) elastomers exhibit unique mechanical properties such as soft elasticity, where the material largely deforms at nearly constant stress, due to microstructural evolution. In this paper, we numerically study the implication of such remarkable soft behavior on the surface instability of a half-space polydomain nematic elastomer, which is uniformly compressed parallel to the interface under a plane-strain condition. We compare the creasing instability of nematic elastomers with that of neo-Hookean elastomers by presenting bifurcation diagrams, stress and strain development in the elastomers, energy relaxation, and surface morphology at the creased state. Our results reveal that soft elasticity stabilizes nematic elastomers in plane-strain compression. Remarkably, the critical strain and stress at which the crease nucleates depend nonlinearly on the degree of anisotropy in nematic elastomers. Moreover, we find that the morphology of the creased surface in nematic elastomers exhibits the universal cusp shape previously observed in neo-Hookean elastomers.多畴液晶(向列)弹性体表现出独特的机械性能，如软弹性，由于微观结构的演变，材料在几乎恒定的应力下很大程度上变形。本文用数值方法研究了在平面应变条件下平行于界面均匀压缩的半空间多域向列弹性体的这种显著的软行为对其表面不稳定性的影响。我们比较了向列弹性体与新胡克弹性体的折痕不稳定性，给出了弹性体的分岔图、应力和应变的发展、能量松弛和折痕状态下的表面形貌。我们的研究结果表明，软弹性在平面应变压缩中稳定了向列弹性体。值得注意的是，折痕成核的临界应变和应力与向列弹性体的各向异性程度呈非线性关系。此外，我们发现向列弹性体的折痕表面形态表现出先前在新胡克弹性体中观察到的通用尖头形状。Analysis of shear localization in viscoplastic solids with pressure-sensitive structural transformationsJ.D. Claytondoi:10.1016/j.jmps.2024.105880具有压敏结构转变的粘塑性固体剪切局部化分析Localization, in the form of adiabatic shear, is analyzed in viscoplastic solids that may undergo structural transformation driven by pressure, shear stress, temperature, and magnetic field. As pertinent to polycrystalline metals, transformations may include solid–solid phase transitions, twinning, and dynamic recrystallization. A finite-strain constitutive framework for isotropic metals is used to solve a boundary value problem involving simple shearing with superposed hydrostatic pressure and constant external magnetic field. Three-dimensional theory is reduced to a formulation simple enough to facilitate analysis without advanced numerical methods, yet sophisticated enough to maintain the salient physics. Ranges of constitutive parameters (e.g., strain hardening, strain-rate sensitivity, thermal softening, and strain-driven structure transformation limits influenced by pressure and magnetic field) are obtained for which localization to infinite shear strain is possible. Motivated by experimental and theoretical studies suggesting a non-negligible role of shear on phase transformations in iron (Fe), the model is used to understand influences of pressure and phase transitions on applied strains for which localization should occur in pure Fe and a high-strength steel. Results show, among other trends for the two materials, that shear localization in conjunction with phase transformation is promoted when the transformed phase is softer than the parent phase. Localization that would occur in the isolated parent phase can be mitigated if strain hardening or thermal softening tendencies of the transformed phase are sufficiently increased or reduced, respectively.在压力、剪切应力、温度和磁场驱动下可能发生结构转变的粘塑性固体中，以绝热剪切形式进行局部化分析。与多晶金属相关，转变可以包括固-固相变、孪生和动态再结晶。采用各向同性金属的有限应变本构框架，求解了具有叠加静水压力和恒外磁场的简单剪切边值问题。三维理论被简化为一个足够简单的公式，可以在没有先进的数值方法的情况下进行分析，但又足够复杂，可以保持显著的物理特性。得到了本构参数的范围(如应变硬化、应变率敏感性、热软化和受压力和磁场影响的应变驱动的结构转变极限)，从而可以局部化到无限剪切应变。由于实验和理论研究表明剪切对铁(Fe)相变的作用不可忽视，该模型用于理解压力和相变对施加应变的影响，这些应变应在纯铁和高强度钢中局部化。结果表明，在两种材料的其他趋势中，当相变相比母相更软时，促进了剪切局部化与相变的结合。如果转变相的应变硬化或热软化倾向分别得到充分的增加或减少，则可以减轻孤立母相中可能发生的局部化。Mechanics of MaterialsA variational method for the simulation of hydrogen diffusion in metalsE.M. Andrés, I. Romerodoi:10.1016/j.mechmat.2024.105166氢在金属中的扩散模拟的变分方法We present a new method for the approximate solution of the strongly coupled, nonlinear stress-diffusion problem that appears when modeling hydrogen transport in metals. The most salient feature of the proposed approximation is that it is fully variational, meaning that all the discrete equations are obtained from the optimality conditions of an incremental potential, even for inelastic mechanical behavior. Like other variational methods, the proposed algorithm has remarkable properties, including the symmetry of the tangent operator, making its solution extremely efficient compared to other similar methods available in the literature.本文提出了一种近似求解金属氢输运模型中出现的强耦合非线性应力扩散问题的新方法。所提出的近似的最显著特征是它是完全变分的，这意味着所有的离散方程都是从增量势的最优性条件中获得的，即使是非弹性力学行为也是如此。与其他变分方法一样，所提出的算法具有显著的性质，包括切线算子的对称性，使其求解与文献中其他类似方法相比非常有效。Thin-Walled StructuresExperimental Investigation of Buckling and Post-Buckling Behaviour of Repaired Composite Laminates Under In-plane Shear LoadingM. Damghani, A. Bugaje, G.A. Atkinson, D. Coledoi:10.1016/j.tws.2024.112489面内剪切荷载作用下修复复合材料层合板屈曲及后屈曲行为试验研究The performance of Ramped Scarf (RS) and Stepped Scarf (SS) repair schemes for highly loaded composite structures has been extensively studied under compressive, tensile, and flexural loadings. However, there is a lack of research on the buckling and post-buckling behaviour of RS and SS repairs under in-plane shear loading, which is critical for aerostructures. This paper addresses this gap by investigating the buckling and post-buckling performance of these repair schemes. Pristine (P) laminates, RS repairs with a scarf angle of 3°, and SS repairs with an overlap step length of 1/60 were manufactured and tested. The quality of the scarf repairs was inspected using artificial intelligence-based machine vision. Mechanical in-plane shear testing was conducted to evaluate the buckling and post-buckling behaviour of P, RS, and SS laminates. The experimental results indicate that RS repairs demonstrated an average of 35% higher maximum displacement and 12% higher failure load compared to pristine laminates. SS repairs showed 19% higher maximum displacement, and 5% higher failure load compared to pristine laminates. RS repairs excelled in all key mechanical performance indicators, including buckling load, Hooke's stiffness, maximum displacement, and failure load, compared to SS repairs. The failure modes of P, RS, and SS laminates were similar. However, RS repairs exhibited greater susceptibility to repair patch detachment compared to SS repairs.在压缩、拉伸和弯曲载荷下，对高载荷复合材料结构的斜面丝巾(RS)和阶梯丝巾(SS)修复方案的性能进行了广泛的研究。然而，对于航空结构至关重要的面内剪切载荷作用下RS和SS修复的屈曲和后屈曲行为，目前还缺乏相关研究。本文通过研究这些修复方案的屈曲和后屈曲性能来解决这一差距。制造和测试了原始(P)层压板，围巾角为3°的RS修复，重叠步长为1/60的SS修复。使用基于人工智能的机器视觉检查围巾修复的质量。力学面内剪切试验进行了评估屈曲和后屈曲行为的P, RS和SS层合板。实验结果表明，与原始层压板相比，RS修复的最大位移平均高出35%，破坏载荷平均高出12%。与原始层压板相比，SS修复的最大位移增加了19%，破坏负荷增加了5%。与SS修复相比，RS修复在所有关键机械性能指标上都表现出色，包括屈曲载荷、胡克刚度、最大位移和失效载荷。P层板、RS层板和SS层板的破坏模式相似。然而，与SS修复相比，RS修复更容易出现修复补丁脱落。来源：复合材料力学仿真Composites FEM

【新文速递】2024年9月21日复合材料SCI期刊最新文章

Composite Structures

Composites Part A: Applied Science and Manufacturing

Composites Part B: Engineering

Composites Science and Technology

【新文速递】2024年9月27日固体力学SCI期刊最新文章