Influence of mode mixity and loading conditions on the fatigue crack growth behaviour of an epoxy adhesive
Influence of mode mixity and loading conditions on the fatigue crack growth behaviour of an epoxy adhesive
复制标题
模式混合和加载条件对环氧粘合剂疲劳裂纹扩展行为的影响
DOI：
10.1111/ffe.13125
复制
发表时间：
2020
影响因子：
3.7
通讯作者：
L. F. Silva
中科院分区：
文献类型：
--
作者：
J. Monteiro;A. Akhavan‐Safar;R. Carbas;E. Marques;R. Goyal;M. El‐zein;L. F. Silva
粘合接头在其使用寿命期间通常会经历混合模式和大部分循环应力条件。当前研究的目的是研究结构环氧粘合剂的疲劳行为。进行了纯模式 I 和 II 以及混合模式测试，以研究粘合剂的断裂和疲劳裂纹扩展 (FCG) 行为。基于柔量的梁法被考虑用于实验断裂能测量。还研究了负载水平和负载比对 I 型 FCG 行为和巴黎定律参数的影响。结果表明，比率越低，载荷水平对疲劳裂纹扩展的影响越明显。研究发现，卸载过程中裂纹面越接近，R2与Gmin/Gm轴之间的差异越大。一些可能性是裂纹闭合现象、测量 Gmin 的困难以及所采用的数据缩减方法。
Adhesive joints usually experience mixed mode and mostly cyclic stresses conditions during their service life. The aim of the current research is to investigate the fatigue behaviour of a structural epoxy adhesive. Pure modes I and II and mixed mode tests were carried out to study the fracture and fatigue crack growth (FCG) behaviour of the adhesive. Compliance‐based beam method was considered for experimental fracture energy measurement. The effects of load level and load ratio on the mode I FCG behaviour and Paris law parameters were also investigated. Result showed that the effect of load level on fatigue crack propagation is more pronounced for lowerRratios. It was found that when the crack faces are closer during the unloading process, the difference between theR2andGmin/Gmaxis higher. Some possibilities are the crack closure phenomenon, difficulty in measuring theGmin, and the employed data reduction approach.