两种厚度的层合板单搭接胶接接头的静力与疲劳性能研究  

Static and fatigue properties of laminate single lap specimens with two thicknesses

作　　者：张茹 陈向明[1] 李新祥[1] 袁菲[1] 程立平[1] ZHANG Ru;CHEN Xiangming;LI Xinxiang;Yuan Fei;CHENG Liping(National Key Laboratory for Strength and Structural Integrity,Aircraft Strength Research Institute of China,Xi'an 710065,China)

机构地区：[1]中国飞机强度研究所强度与结构完整性全国重点试验室,西安710065

出　　处：《复合材料科学与工程》2024年第7期86-92,共7页Composites Science and Engineering

基　　金：民机科研(MJ-2015-F-038)。

摘　　要：针对两种厚度的复合材料单搭接胶接接头开展了静力与疲劳试验研究和静力数值分析。用虚拟裂纹闭合技术模拟搭接胶接界面,研究单搭接试件在轴向拉伸载荷作用下的裂纹起始和扩展原理。结果显示:损伤起始时刻,G_(Ⅲ)远远小于G_(Ⅰ),G_(Ⅱ);G_(Ⅰ)随着裂纹长度的增加而减小,G_(Ⅱ)随裂纹长度的增加而增大;界面损伤起始主要受面外剥离力的影响,裂纹扩展主要受滑移剪切力的作用。设计两种厚度的复合材料单搭接胶接接头的疲劳试验,得到了不同疲劳载荷下试件的疲劳寿命,并给出相应裂尖G_(Ⅰ)/G_(Ⅰ)C,G_(Ⅱ)/G_(Ⅱ)C的值;绘制N-G_(Ⅰ)/G_(Ⅰ)C,G_(Ⅱ)/G_(Ⅱ)C曲线发现,寿命随G_(Ⅰ)/G_(Ⅰ)C增加的递减幅度远远大于随G_(Ⅱ)/G_(Ⅱ)C变化的幅度;对比试件胶接界面破坏形式发现,与粘接层较薄试验件相比,粘接层较厚的试验件界面破坏形式较平滑,且胶层破坏面积所占比例较高;随着疲劳载荷值的增加,搭接区域胶层破坏面积所占比例减小,被粘接的复合材料纤维层撕裂面积增加。The mechanical properties and fatigue characteristics of the single lap bonded surface made of two different thicknesses of composite materials were studied through a combination of experimental research and numericalsimulation.Virtual crack closure technique(VCCT)was used to simulate the bond interface,and the crack initiation and propagation principle of single lap specimens under axial tensile load was studied.It was found that at the damage initiation time G_(Ⅲ)was much smaller than G_(Ⅰ)and G_(Ⅱ),while G_(Ⅰ)decreased and G_(Ⅱ)increased with increasing crack length.The out-of-plane peeling stress mainly affected the interface damage initiation,while the sliding shear stress mainly affected the crack propagation.Fatigue tests were designed for the composite single lap specimens of two thicknesses to determine their fatigue life under different fatigue loads.The values of G_(Ⅰ)/G_(Ⅰ)C and G_(Ⅱ)/G_(Ⅱ)C of the corresponding crack tips were given.N-G_(Ⅰ)/G_(Ⅰ)C and G_(Ⅱ)/G_(Ⅱ)C curves are drawn,and it was found that the range of life decrease with the increase of G_(Ⅰ)/G_(Ⅰ)C was much larger than that of G_(Ⅱ)/G_(Ⅱ)C.The failure forms of the adhesive interface were compared,and it was found that the failure forms of the test pieces with thicker adhesive layers were smoother than those with thinner adhesive layers,and the failure area of the adhesive layer accounted for a higher proportion.With an increase in fatigue load value,the proportion of the failure area of the adhesive layer in the lap area decreased,while the tear area of the bonded composite fiber layer increased.

关 键 词：层合板 单搭接 胶接界面 虚拟裂纹闭合技术 疲劳 复合材料 

分 类 号：TB332[一般工业技术—材料科学与工程]