单向增强玻璃钢复合材料静/动态拉伸实验研究

Static/dynamic tensiletest of unidirectional reinforced GFRP composites

本文针对单向增强玻璃钢复合材料,进行了一系列静/动态拉伸试验,利用高速摄影与DIC相结合的方法,获得了材料不同方向、不同应变率的应力-应变曲线以及材料在不同方向上的动态失效应变,精确地描述了材料的静/动态拉伸及失效行为。实验结果表明,纤维增强方向在不同应变率(10^-3、10、10^2 s^-1)拉伸应力-应变曲线均存在一个刚度减小的刚度变化点N,变化后的Echanged分别为初始弹性模量Einitial的67.5%、39.0%、21.4%。此材料在不同应变率(10^-3、10、10^2 s^-1)拉伸情况下,纤维增强的方向1上强度最高(分别为608、967、1 123 MPa),方向2强度最低(分别为75、67、58 MPa),方向3强度较低(分别为90、151、221 MPa)。利用高速摄影与DIC相结合的方法,获得了100 s^-1应变率下,不同铺层方向破坏时刻的动态失效参数(方向1~3的动态失效应变分别为0.267、0.078、0.099),可以更加精确地描述此单向增强玻璃钢复合材料的动态失效行为。

In this paper, a series of static/dynamic tensile tests are performed for unidirectionally reinforced GFRP composites. Using the combination of high-speed photography and DIC (digital image correlation) technology, true stress-strain curves in different directions and strain rates are obtained. We also obtained the dynamic failure strain of the material in different directions, which are used to accurately describe the dynamic tensile and failure behavior of the material. The experimental results show that there is a stiffness change point N in the fiber reinforcement direction under different strain rate (10^-3, 10,10^2 s^-1) tensile conditions, and the modulus Echanged is 67.5%, 39% and 21.4% of the initial elastic modulus Einitial, respectively. The fiber has the highest strength in the 1 direction which is reinforced (608, 967 and 1 123 MPa, respectively) under different strain rates (10^-3, 10 and 10^2 s^-1). The direction 2 has the lowest strength (75, 67 and 58 MPa, respectively). The strength of direction 3 is a little weak (90, 151 and 221 MPa, respectively). With the combination of high-speed photography and the DIC technology, the dynamic failure parameters of different directions under the strain rate of 100 s^-1 are obtained. The dynamic failure strain in 1-3 directions is 0.267, 0.078 and 0.099 respectively. The dynamic failure behavior of this unidirectional reinforced fiberglass composite can be more accurately described.