Experimental study of postcritical deformation stage realization in layered composites during tension using digital image correlation and acoustic emission  

基于数字图像相关和声发射技术的层状复合材料拉伸后临界变形阶段实现的实验研究

作　　者：Valeriy Wildemann Elena Strungar Dmitrii Lobanov Artur Mugatarov Ekaterina Chebotareva Vaeriy Widemann;Eena Strungar;Dmitrii Lobanov;Artur Mugatarov;Ekaterina Chebotareva

机构地区：[1]Center of Experimental Mechanics,Perm National Research Polytechnic University,Perm 614990,Russian Federation

出　　处：《Acta Mechanica Sinica》2025年第2期163-175,共13页力学学报(英文版)

基　　金：This work was supported by the Russian Science Foundation(Grant No.22-19-00765)at the Perm National Research Polytechnic University.

摘　　要：Creating conditions to implement equilibrium processes of damage accumulation under a predictable scenario enables control over the failure of structural elements in critical states.It improves safety and reduces the probability of catastrophic behavior in case of accidents.Equilibrium damage accumulation in some cases leads to a falling part(called a postcritical stage)on the material’s stress-strain curve.It must be taken into account to assess the strength and deformation limits of composite structures.Digital image correlation method,acoustic emission(AE)signals recording,and optical microscopy were used in this paper to study the deformation and failure processes of an orthogonal-layup composite during tension in various directions to orthotropy axes.An elastic-plastic deformation model was proposed for the composite in a plane stress condition.The evolution of strain fields and neck formation were analyzed.The staging of the postcritical deformation process was described.AE signals obtained during tests were studied;characteristic damage types of a material were defined.The rationality and necessity of polymer composites’postcritical deformation stage taken into account in refined strength analysis of structures were concluded.在可预测的情况下,实现损伤累积平衡过程的条件能够控制关键状态下结构元件的失效.这提高了安全性,并降低了事故中灾难性行为发生的概率.在某些情况下,平衡损伤累积会导致材料应力-应变曲线上的下落区(称为后临界阶段).为了评估复合材料结构的强度和变形极限,必须考虑这一点.本文使用数字图像相关方法、声发射信号记录和光学显微镜研究了正交铺设复合材料在不同方向上拉伸至各向同性轴时的变形和失效过程,提出了平面应力条件下复合材料的弹塑性变形模型,分析了应变场的演化和颈缩的形成,描述了后临界变形过程的阶段划分,研究了测试期间获得的声发射信号,定义了材料的特征损伤类型,得出在结构强度分析中考虑聚合物复合材料后临界变形阶段的合理性和必要性的结论.

关 键 词：Experimental mechanics Digital image correlation method Acoustic emission Postcritical deformation Polymer composite 

分 类 号：O347.1[理学—固体力学]