含孔复合材料层合板静拉伸损伤演化的实验和表征方法

发布时间：2019-04-12 09:07

【摘要】：为了深入探究复合材料层合板结构的损伤机理和损伤演化,应用声发射技术和图像相关技术同步实时监测含孔碳纤维复合材料层合板试样在静拉伸过程中的损伤演化。实验结果表明,试样表面应变场呈现局部化特征。对应变集中带在加载方向的应变值进行了统计分析,获得了应变场的特征统计量(标准差)随加载的演化模型。层合板损伤时产生声发射信号的峰值频率大小能够有效区分复合材料的损伤模式,由此,建立了基于损伤模式累积声发射数的损伤演化模型。通过对应变场演化模型和声发射损伤演化模型的分析,可以将复合材料的损伤演化分为损伤初始阶段、损伤平稳扩展期、损伤严重阶段三个部分。统计分析结果表明:在损伤严重阶段,基于声发射事件数的各种损伤的损伤变量和局部应变场标准差快速增长,因此局部应变场统计标准差可以作为后期局部损伤严重程度的识别指标。
[Abstract]:In order to investigate the damage mechanism and damage evolution of composite laminates, acoustic emission technique and image correlation technique were applied to monitor the damage evolution of carbon fiber composite laminates with holes in the process of static tension. The experimental results show that the strain field on the surface of the specimen is localized. The strain values in the loading direction of the strain concentration band are statistically analyzed, and the evolution model of the characteristic statistics (standard deviation) of the strain field with loading is obtained. The peak frequency of acoustic emission signals generated during laminate damage can effectively distinguish the damage modes of composite materials. Thus a damage evolution model based on the cumulative acoustic emission number of damage modes is established. The damage evolution of composites can be divided into three parts: the initial stage of damage, the stable period of damage propagation and the stage of serious damage through the analysis of corresponding variable field evolution model and acoustic emission damage evolution model. The results of statistical analysis show that the damage variables and the standard deviation of local strain field based on the number of acoustic emission events increase rapidly in the severe stage of damage. Therefore, the statistical standard deviation of local strain field can be used as an index to identify the severity of local damage.
【作者单位】：江苏大学土木工程与力学学院;江苏理工学院材料工程学院;
【基金】：国家自然科学基金(No.11272138,No.11402101)资助
【分类号】：TB332

【相似文献】