【新文速递】2024年4月19日固体力学SCI期刊最新文章

 

今日更新：International Journal of Solids and Structures 2 篇，Journal of the Mechanics and Physics of Solids 2 篇，Thin-Walled Structures 1 篇

International Journal of Solids and Structures

Steady-state crack propagation during DCB test with viscoelastic-viscoplastic interface - Correlation between rheological behavior and effect of crack propagation rate

Julien Jumel

doi:10.1016/j.ijsolstr.2024.112824

粘弹粘塑性界面下DCB试验的稳态裂纹扩展——流变行为与裂纹扩展速率影响的关系

Adhesively bonded joints are known to suffer from creep and relaxation phenomena due to the viscous nature of the adhesive. These effects are detrimental to the durability of structural joints as they can lead to progressive and slow crack propagation rate phenomena and possible delayed failure. Master curve approaches are often used to assess the durability of structural assemblies, but the physical justification for such approaches requires additional investigation to more accurately assess the coupling between structural effects and the possible complex long-term rheological behaviour of the adhesive layer. Following similar approaches developed to study the steady-state crack propagation regime in bulk materials, an Eulerian description of crack propagation along a viscous adhesive layer during a double cantilever beam test is implemented. Taking into account viscoelastic-viscoplastic and various hardening rules, some master curves can be obtained describing the evolution of the crack propagation rate as a function of the stationary loading conditions. With such a model, the role of adhesive layer behaviour and joint geometry on crack propagation conditions can be discussed, as well as the applicability of such a master curve approach.

由于胶粘剂的粘性，胶粘剂连接的接头会出现蠕变和松弛现象。这些影响对结构节点的耐久性是不利的，因为它们会导致渐进和缓慢的裂纹扩展速率现象，并可能导致延迟破坏。主曲线方法通常用于评估结构组件的耐久性，但这种方法的物理合理性需要额外的研究，以更准确地评估结构效应与粘合层可能复杂的长期流变行为之间的耦合。采用类似的方法来研究块状材料的稳态裂纹扩展，实现了双悬臂梁试验中沿粘性粘接层裂纹扩展的欧拉描述。考虑粘弹粘塑性和各种硬化规律，可以得到一些描述裂纹扩展速率随固定加载条件的演化的主曲线。利用该模型，可以讨论粘接层行为和接缝几何形状对裂纹扩展条件的作用，以及这种主曲线方法的适用性。

Cross-sectional analysis of initially curved composite beams with rectangular and circular sections using an asymptotic meshless method

Saeid Khadem Moshir, Suong V. Hoa, Farjad Shadmehri

doi:10.1016/j.ijsolstr.2024.112827

用渐近无网格法分析矩形和圆形截面初弯曲组合梁的截面

An analytical meshless cross-sectional dimensional reduction method is developed to perform structural analysis of initially curved composite beams. By introducing the Pascal polynomials in the Cartesian coordinates system for beams with rectangular cross-sections and in the polar coordinates system for the beams with circular cross-sections to the warping field, a three-dimensional beam problem can be split into a two-dimensional cross-sectional analysis and a one-dimensional along the reference line of the beam. The obtained cross-sectional stiffness matrix based on higher-order of the strain energy can be incorporated into a one-dimensional finite element solution for initially curved composite beams, for the purpose of strain and stress analysis. Finally, the three-dimensional strain through the thickness of the beam can be achieved by the recovery analysis. The present method takes advantage of Pascal polynomials so that the solution procedure will be more simplified and computationally more efficient compared to three-dimensional finite element (3D FE) method. The proposed method for different isotropic and anisotropic beams is examined and compared with the literature, 3D FE, and Variational Asymptotic Beam Sectional (VABS) package which is a finite element based cross-sectional analysis tool for composite beams.

提出了一种分析无网格截面降维方法，对初弯组合梁进行结构分析。将直角截面梁的笛卡尔坐标系和圆截面梁的极坐标系中的Pascal多项式引入翘曲场，将三维梁问题分解为二维截面分析和沿梁参考线的一维解析。基于应变能高阶的截面刚度矩阵可纳入初弯曲组合梁的一维有限元解中，用于应变和应力分析。最后，通过恢复分析，可以得到随梁厚度变化的三维应变。该方法利用了Pascal多项式，与三维有限元法相比，求解过程更加简化，计算效率更高。对不同各向同性和各向异性梁的方法进行了检验，并与文献、三维有限元和基于有限元的组合梁截面分析工具变分渐近梁截面(VABS)软件包进行了比较。

Journal of the Mechanics and Physics of Solids

Modeling solidification cracking: A new perspective on solid bridge fracture

Wenbin Liu, Gan Li, Jian Lu

doi:10.1016/j.jmps.2024.105651

模拟凝固裂纹:研究固体桥梁断裂的新视角

Solidification cracking is a longstanding and serious problem in metallurgical engineering that is encountered during casting, welding, and additive manufacturing. Extensive research has been conducted on the cracking susceptibility associated with solidification paths, microstructural effects, and thermal conditions, but it remains highly challenging to precisely predict and evaluate the solidification cracking, especially its solid bridging and grain size dependence. In this study, a new theoretical model based on solid bridge fracture is proposed for modeling solidification cracking. The occurrence of cracking depends on competition between thermal stress accumulation and solid-bridge strength development, which is fundamentally distinct from existing models in which the occurrence of cracking depends on liquid feeding. A crack-like structure is utilized to determine the thermal stress at a dendrite root, and demonstrates the absence of stress singularity in a solidifying crack. Grain features are incorporated to show that grain refinement effectively inhibits cracking by lowering the rate of accumulation of thermal stress. Hence, the cracking susceptibility is quantified based on grain size distributions. Numerical analyses of binary aluminum alloys validate the proposed model and provide a rational interpretation of reported experimental results in terms of cracking susceptibility, grain size effects, and cooling rate effects. This study presents and validates one of the first solid-bridge fracture-based solidification cracking models, and thus provides a new perspective to support investigation of solidification cracking.

凝固开裂是冶金工程中一个长期存在的严重问题，在铸造、焊接和增材制造过程中都会遇到。人们已经对与凝固路径、微观组织效应和热条件相关的裂纹敏感性进行了广泛的研究，但要准确预测和评估凝固裂纹，特别是其固体桥接性和晶粒尺寸依赖性，仍然是一项极具挑战性的工作。本文提出了一种新的基于固体桥梁断裂的理论模型来模拟凝固裂纹。开裂的发生取决于热应力积累和固体桥梁强度发展之间的竞争，这与现有的开裂发生取决于液体进料的模型有本质区别。利用类裂纹结构来确定枝晶根部的热应力，并证明在凝固裂纹中不存在应力奇点。结合晶粒特征表明，晶粒细化有效地抑制了裂纹通过降低热应力的积累速度。因此，基于晶粒尺寸分布来量化裂纹敏感性。对二元铝合金的数值分析验证了所提出的模型，并从开裂敏感性、晶粒尺寸效应和冷却速率效应等方面对已有的实验结果进行了合理的解释。本研究提出并验证了第一个基于固体桥梁断裂的凝固开裂模型，从而为支持凝固开裂的研究提供了一个新的视角。

Micro-mechanics investigation of heterogeneous deformation fields and crack initiation driven by the local stored energy density in austenitic stainless steel welded joints

Lifeng Gan, Baoyin Zhu, Chao Ling, Dongfeng Li, Esteban P. Busso

doi:10.1016/j.jmps.2024.105652

奥氏体不锈钢焊接接头局部存储能量密度驱动的非均匀变形场和裂纹起裂细观力学研究

This work investigates the heterogeneous deformation and failure of HR3C austenitic stainless steel welded joints at room and typical service temperatures. Such types of welded joints are widely used in the new generation of fossil fuel power stations and are known to suffer from premature high temperature failure. Observation of in-service failures revealed that cracks may nucleate either in the heat affected zone or in the weld metal. The main objective of this work is to identify the local microstructural conditions and stress–strain fields responsible for both ductile failure and micro-crack nucleation within the weldment at low and high temperatures, respectively. To that purpose, a novel multi-scale micromechanics-based modelling framework is proposed. It relies on representative weld microstructure models digitally reconstructed from EBSD measurements, and dislocation density-based crystal plasticity models to describe the behaviour of individual grains in each weld region. A novel thermo-dynamically consistent relation for the configuration stored energy per unit volume is derived from the crystal plasticity framework.The single crystal models are calibrated and validated from a combination of uniaxial tensile tests on cross-weld specimens using high resolution digital image correlation techniques, representative volume elements of the polycrystals at the macro-scale, as well as micropillar compression tests at the scale of the individual grains. Predictions of heterogeneous inelastic deformation fields within the weldment at both 22 °C and 665 °C, and of micropillar compression behaviour of the individual weld single crystal phases are consistent with experimental data. The experimentally observed ductile failure of the weld metal at room temperature is successfully predicted using a Gurson-type void nucleation, growth and coalescence constitutive model. The suitability of the stored strain energy density and the accumulated plastic strain as crack initiation/creep failure indicators is investigated. It was found that predicted creep lifetimes with either indicator were very similar, and that they were relatively accurate for low stress levels.

本文研究了HR3C奥氏体不锈钢焊接接头在室温和典型工作温度下的非均质变形和破坏。这种类型的焊接接头广泛应用于新一代化石燃料电站，并且已知存在过早高温失效的问题。对在役失效的观察表明，裂纹可能在热影响区或焊缝金属中成核。这项工作的主要目的是确定在低温和高温下焊接件内的局部微观组织条件和应力-应变场，分别负责韧性破坏和微裂纹形核。为此，提出了一种新的基于多尺度细观力学的建模框架。它依赖于由EBSD测量数字重建的代表性焊缝微观结构模型，以及基于位错密度的晶体塑性模型来描述每个焊缝区域单个晶粒的行为。从晶体塑性框架出发，导出了单位体积构型存储能量的一种新的热力学一致性关系。通过使用高分辨率数字图像相关技术对交叉焊接试样进行单轴拉伸试验，在宏观尺度上进行多晶的代表性体积元素，以及在单个晶粒尺度上进行微柱压缩试验，对单晶模型进行校准和验证。在22°C和665°C下，焊件内非弹性变形场的预测以及单个焊缝单晶相的微柱压缩行为与实验数据一致。利用gurson型孔洞形核、生长和聚结本构模型，成功地预测了焊接金属在室温下的延性破坏。研究了储存应变能密度和累积塑性应变作为裂纹萌生/蠕变破坏指标的适用性。发现预测蠕变寿命与任何一个指标是非常相似的，他们是相对准确的低应力水平。

Thin-Walled Structures

Experiments and design of a kirigami-based multi-stage energy absorption structure subjected to axial impact

Baofeng Ruan, Lele Zhang, Weiyuan Dou, Ding Zhang, Sebastian Stichel

doi:10.1016/j.tws.2024.111920

轴向冲击多级吸能结构的试验与设计

As a typical energy-absorbing structure, the thin-walled structure dissipates impact energy through the formation of plastic hinges and material failure. The geometric configuration of the energy-absorbing structure deeply influences its response to impact loads. For a certain load curve required by collision scenarios, this study proposes a novel design method for approximating a continuous impact load curve with discretized ones. Based on kirigami structures, the conceptual framework integrates multi-module and multi-stage designs to regulate segmental stiffness through theoretical analysis, thereby achieving the desired curve approximation. The effectiveness of the proposed kirigami-based multi-stage energy absorption structure (KMS) is validated by drop-weight impact tests and numerical simulations. Findings demonstrate that the KMS effectively dissipates impact energy in a progressive manner, aligning with the desired load curve and inducing stable and orderly structural deformation under axial impact. Through appropriate parameter design, the deformation mode and the inducing effect of the kirigami structure can be managed, enabling the structure's adaptability to diverse collision scenarios.

薄壁结构是一种典型的吸能结构，通过塑性铰的形成和材料的破坏来耗散冲击能。吸能结构的几何形态对其冲击响应有很大影响。针对某一碰撞场景所需要的载荷曲线，提出了一种用离散化载荷曲线逼近连续冲击载荷曲线的设计方法。概念框架基于kirigami结构，结合多模块、多阶段设计，通过理论分析调节节段刚度，从而实现所需的曲线逼近。通过落锤冲击试验和数值模拟验证了该多级吸能结构的有效性。结果表明:在轴向冲击下，KMS能有效地逐步耗散冲击能量，与期望载荷曲线对齐，诱导结构稳定有序变形;通过适当的参数设计，可以控制基里伽米结构的变形模式和诱导效果，使其能够适应不同的碰撞场景。