加载速率对层间断裂韧性的影响

虽然加载速率对层间断裂的影响已经被广泛的研究,但是现有的研究结果还未能给出加载速率对层间断裂韧性影响的明确趋势。研究人员发展了许多测量层合板复合材料以及胶接层断裂韧性的实验方法。本文的主要目的是对层间断裂韧性测量的实验方法进行综述,尤其是准静态和动态加载条件下层间起裂韧性的测量。首先介绍了准静态下Ⅰ型、Ⅱ型以及Ⅰ/Ⅱ复合型层间断裂韧性的测量方法,然后综述动态加载下层间断裂韧性的实验方法。前两部分着重介绍断裂实验中断裂参数(载荷、位移、起裂时间以及裂纹长度)的测量以及断裂韧性的计算。之后又综述了两种光学测量方法在层间断裂实验中的应用。最后将文献中加载速率对层间断裂韧性影响的实验研究结果进行了总结。

Loading rate effect on interlaminar fracture toughness

Loading rate effect on the interlaminar fracture toughness has been extensively investigated. However, a study of the published literature indicates that considerable disagreement still exists and a clear understanding of this highly important issue has yet to be achieved. Various loading configurations and the corresponding experimental methods have been developed to date for measuring dynamic interlaminar fracture toughness of laminated composites and adhesive joints. The main purpose of this paper is to review the interlaminar fracture test, especially the technique to gain the initiation fracture toughness under quasi-static and dynamic loading conditions. Firstly, the experimental technics to measure Mode I, Mode II and Mode I/II interlaminar fracture toughness under quasi-static loading conditions are introduced. Secondly, experimental methods to study the dynamic interlaminar fracture mechanisms are reviewed. These two parts focus on the methods used for determining fracture parameters (load, displacement, initial fracture time, crack length) and fracture toughness, such as theoretical formula, FEM and strain gauges, especially for the dynamic experiments. In the third part of the paper, two main optical measurement techniques used in interlaminar fracture tests are introduced. The last part summaries many of the reported findings of the loading rate effect on the interlaminar fracture toughness.