【新文速递】2023年11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，Mechanics of Materials 1 篇，Thin-Walled Structures 2 篇

International Journal of Solids and Structures

Multi-scale numerical simulation of fracture behavior for the gadolinia-doped ceria (GDC) under mechano-electrochemical coupling fields at high temperature

Huang Runze, Sun Yi, Yang Zhiqiang

doi:10.1016/j.ijsolstr.2023.112564

高温机械-电化学耦合场下钆掺杂陶瓷（GDC）断裂行为的多尺度数值模拟

The fracture toughness of gadolinia-doped ceria (GDC) solid oxide fuel cells (SOFCs) electrolyte with a central crack is significantly reduced under the mechano-electrochemical coupling fields at high temperature. In this work, an atom-to-continuum (AtC) multi-scale method combining the finite element method (FEM) and the molecular dynamics (MD) simulation is developed. Firstly, the AtC multi-scale method is validated by investigating the uniaxial tensile stress-strain curves of GDC with a central crack at different temperatures. Then, based on the theory of fracture mechanics, the macrostructure of GDC is transformed into a microscopic intermediate transition model, and a detailed computational procedure for analyzing the fracture toughness of the macrostructure of the GDC is given by the AtC multi-scale method. Finally, the fracture toughness of GDC macrostructure under the mechano-electrochemical coupling fields is studied by the proposed approach. The simulation results show that the fracture toughness of 10GDC and 20GDC under the mechano-electrochemical coupling fields is clearly reduced compared to the uniaxial tensile loading. Among them, the fracture toughness of 10GDC under the mechano-electrochemical coupling fields is decreased by 12.28% and 30.67% at 800℃ and 900℃, and the fracture toughness of 20GDC under the mechano-electrochemical coupling fields is decreased by 17.25% and 29.52% at 800℃ and 900℃. These findings are critical in predicting the fracture behavior of GDC electrolyte under real working conditions.

钆掺杂铈（GDC）固体氧化物燃料电池（SOFCs）电解质在高温机械-电化学耦合场作用下，中心裂纹的断裂韧性显著降低。本研究开发了一种结合有限元法（FEM）和分子动力学（MD）模拟的原子到连续（AtC）多尺度方法。首先，通过研究带有中心裂纹的 GDC 在不同温度下的单轴拉伸应力-应变曲线，验证了 AtC 多尺度方法。然后，基于断裂力学理论，将 GDC 的宏观结构转化为微观中间过渡模型，并通过 AtC 多尺度方法给出了分析 GDC 宏观结构断裂韧性的详细计算程序。最后，利用所提出的方法研究了机械-电化学耦合场下 GDC 宏观结构的断裂韧性。模拟结果表明，与单轴拉伸加载相比，10GDC 和 20GDC 在机械电化学耦合场下的断裂韧性明显降低。其中，10GDC在机械电化学耦合场下的断裂韧性在800℃和900℃时分别降低了12.28%和30.67%，20GDC在机械电化学耦合场下的断裂韧性在800℃和900℃时分别降低了17.25%和29.52%。这些发现对于预测 GDC 电解液在实际工作条件下的断裂行为至关重要。

Mechanics of Materials

The viscoelastic behavior of lignin: Quantification through nanoindentation relaxation testing on hot-pressed technical lignin samples from various origins

Schwaighofer Michael, Königsberger Markus, Zelaya-Lainez Luis, Lukacevic Markus, Serna-Loaiza Sebastián, Harasek Michael, Zikeli Florian, Friedl Anton, Füssl Josef

doi:10.1016/j.mechmat.2023.104864

木质素的粘弹性行为：通过对不同产地的热压工业木质素样品进行纳米压痕松弛测试进行量化

Lignin, the second most abundant organic polymer on earth, is one of the primary causes of the viscoelastic behavior of plants. An accurate characterization of its viscoelastic properties is essential for predicting the time-dependent response of natural materials, including wood and plant fibers, and for advancing lignin-based materials and their production methods, such as 3D printing of biocomposites. To enrich the still rather sparse knowledge on the viscoelasticity of lignin, we re-evaluate nanoindentation relaxation tests performed on five hot-pressed technical lignins extracted from different feedstocks, using three different extraction methods. The viscoelastic indentation problem is addressed using the method of functional equations combined with the homogenization theory to account for the production-induced porosity. This evaluation procedure allows for quantitatively assessing the viscoelastic properties of lignin, which can be very accurately described by an isochoric four-parameter Burgers model. Remarkably, the viscoelastic properties of all tested lignins are practically identical and independent of the feedstock and the extraction processes.

木质素是地球上含量第二高的有机聚合物，是植物粘弹性行为的主要成因之一。准确描述木质素的粘弹性能对于预测木材和植物纤维等天然材料随时间变化的响应，以及推进木质素基材料及其生产方法（如生物复合材料的三维打印）至关重要。为了丰富有关木质素粘弹性的知识，我们采用三种不同的提取方法，对从不同原料中提取的五种热压工业木质素进行了纳米压痕松弛测试。粘弹性压痕问题采用函数方程法结合均质化理论来解决，以考虑生产引起的孔隙率。该评估程序可定量评估木质素的粘弹性能，并可通过等速四参数伯格斯模型对其进行非常精确的描述。值得注意的是，所有受测木质素的粘弹性能几乎完全相同，且不受原料和提取工艺的影响。

Thin-Walled Structures

Seismic Performance of Weak-Beam-Type Steel Low-to-Middle-Rise Moment-Resisting Frame Determined by Local Buckling of Square Hollow Section Columns

Yamada Satoshi, Miyazawa Hiroki, Iyama Jun

doi:10.1016/j.tws.2023.111359

通过方形空心截面柱的局部屈曲确定弱梁型钢中低层力矩支撑框架的抗震性能

This study performed incremental dynamic analyses to investigate the relationship between the seismic performance and deformation capacity of the column of weak-beam-type steel moment-resisting frames (MRFs) with square hollow section (SHS) columns. A hysteresis model that accurately simulates the local buckling cyclic behavior was used for the analysis. From analytical results, a relationship between the required strength of the weak-beam-type steel MRFs and the width-to-thickness ratio of the SHS columns was obtained. Also, safety margin of MRFs up to collapse was evaluated in the relationship with the width-to-thickness ratio of the SHS column.

本研究进行了增量动态分析，以研究采用方形空心截面（SHS）柱的弱梁型钢力矩抵抗框架（MRF）的抗震性能与柱变形能力之间的关系。分析中使用了能精确模拟局部屈曲循环行为的滞后模型。根据分析结果，得出了弱梁型钢 MRF 所需强度与 SHS 柱宽厚比之间的关系。此外，还评估了 MRF 在坍塌前的安全裕度与 SHS 柱的宽厚比之间的关系。

High-fidelity prediction and temperature-rise mechanism for low-velocity impact of triaxially braided composites

Liu Peng, Cai Yinglong, Zhao Zhenqiang, Zhang Chao

doi:10.1016/j.tws.2023.111360

三轴编织复合材料低速冲击的高保真预测和温升机制

An elastoplastic mechanical-thermal constitutive model was integrated into the development of a mesoscale finite element model. This model aimed to analyze the temperature rise phenomenon and failure behavior of composites under impact loading conditions. Triaxially braided carbon/epoxy composite specimens were subjected to low-velocity impact using a drop weight tester, and the temperature variations within the specimens were monitored using an infrared camera. The numerical predictions successfully reproduced the observed failure modes and accurately captured the temperature distribution. A numerical study was performed to explore the main factors of temperature rise, indicating that plastic work of pure matrix and fracture transformed energy of fiber tow are the primary sources of temperature rise. The transverse specimen was found to exhibit superior energy absorption capacity under high-energy impacts.

在中尺度有限元模型的开发过程中集成了弹塑性机械-热构成模型。该模型旨在分析复合材料在冲击加载条件下的温升现象和破坏行为。使用落锤试验机对三轴向编织碳/环氧复合材料试样进行低速冲击，并使用红外摄像机监测试样内部的温度变化。数值预测成功地再现了观察到的失效模式，并准确捕捉到了温度分布。数值研究探讨了温升的主要因素，表明纯基体的塑性功和纤维束的断裂转化能是温升的主要来源。研究发现，横向试样在高能冲击下表现出卓越的能量吸收能力。