在不同应力水平下, 对玻璃纤维增强乙烯基树脂基复合材料层合板进行拉 拉疲劳试验; 试验数据采用对数形式进行曲线拟合, 获得S N 曲线。 玻璃纤维增强复合材料随着应力幅的降低, 持久极限循环次数显著增加, 呈现出大幅度的增加趋势。 根据曲线推测, 应力幅再降低时, 持久极限循环次数会增加更多。 其失效过程一般为玻璃纤维与基体界面脱胶、玻璃纤维断裂、基体裂纹; 也造成该区域的应力集中, 树脂基体裂纹不断扩展, 直至玻璃纤维与树脂基体完全脱离, 形成分层玻璃纤维断裂。

Through the tensile-fatigue test of glass fiber reinforced vinyl resin matrix composite laminates at different stress levels, the test data are fitted in logarithmic form to obtain the S-N curve. With the decrease of stress amplitude, the number of endurance limit cycles of glass fiber reinforced composites increases significantly, showing a significant increasing trend. At the same time, it is inferred from the curve that when the stress amplitude decreases again, the number of endurance limit cycles will increase more. The failure process is generally degumming at the interface between glass fiber and matrix, glass fiber fracture and matrix crack; stress concentration will occur in this area, and the resin matrix crack continues to expand until the glass fiber is completely separated from the resin matrix, forming layered glass fiber fracture.