树脂基复合材料L型板承载性能及其破坏过程试验研究

Experimental Study on the Bearing Capacity and the Damage Process of the CFRP L-Shaped Specimens

本文针对树脂基复合材料L型板,为模拟其在典型机械载荷作用下的承载能力及破坏过程,设计了仅约束端部平动自由度的夹具,并借助楔形夹具,分别实现了端部可面内转动和固支两种夹持状态。首次采用数字图像相关、高速摄像和声发射技术相结合的监测方案,开展了典型机械载荷作用下L型板力学性能试验,同时获得了加载过程中试样的面内应变场、表面破坏过程、及内部损伤产生的声发射信号。试验结果表明,不同端部夹持方式下L型板的极限拉伸承载力略有差异,在内侧圆角处和外侧边缘试样先后发生破坏,其面内应变由对称分布转为非对称分布,并产生能量较大的声发射信号。L型板的压缩极限承载力低于拉伸极限承载力,仅在内侧圆角处产生破坏,沿宽度方向扩展并贯穿整个试样。

This paper carried out experimental studies on the bearing capacity and damage process of the CFRP L-Shaped Specimens under typical mechanical load. Two types of fixture were designed to implement different boundary conditions of the edge of the specimen, translational fixed boundary and fully fixed boundary. Digital image correlation system, high-speed camera and acoustic emission test system was simultaneously employed for the first time to capture the in-plane strain field, damage process, and acoustic emission signals of the L-shaped specimen, respectively, during the test procedure. The results showed that the maximum tensile load of the L-shaped specimen is different under different loading methods. Damages initiate at the inner corner and the outside edge of the specimen, high-energy acoustic emission signals generate during the propagation of the cracks. In-plane strain distribution on the surface changes from symmetrical to asymmetrical. The maximum compressional load of the specimen is lower than the maximum tensile load, and the damage occurs only at the inner corner and propagates along the width of the specimen.