Fatigue Life and Residual Strength prediction of GFRP Composites: An Experimental and Theoretical approach

Abstract This paper presents the fatigue behavior of Glass Fiber Reinforced Polymer (GFRP) composites at constant amplitude tension-tension loading conditions. A two parameter residual strength and fatigue life model has been proposed by accounting the effect of stress ratio when the structure undergoes continuous loading. A model is also developed to predict the fatigue life of GFRP composites based on fatigue endurance limit. Experiments were conducted on GFRP composite specimens to predict fatigue life and residual strength at various stress levels. Tests were also conducted to gain an understanding of the tensile behavior of GFRP composite specimens under different quasistatic strain rates. The lowest tensile strength resulting from strain rate studies has been used ultimately for conducting fatigue life and residual strength tests. Reliability of the proposed models has been verified with experimental results and with the models seen in literature.

摘要 本文针对玻璃纤维增强聚合物（Glass Fiber Reinforced Polymer，GFRP）复合材料在等幅拉-拉载荷条件下的疲劳行为展开研究。针对结构承受持续载荷时的应力比影响效应，本文提出了双参数剩余强度与疲劳寿命模型。同时，基于疲劳极限构建了用于预测GFRP复合材料疲劳寿命的专用模型。本文制备GFRP复合材料试样开展两类试验：其一为不同应力水平下的疲劳寿命与剩余强度测试，以获取对应试验数据；其二为不同准静态应变率下的试样拉伸行为测试，以明晰该材料的拉伸特性。本研究最终选取应变率试验所得的最低拉伸强度作为基准参数，开展后续的疲劳寿命与剩余强度测试。所提模型的可靠性已通过试验结果与现有文献中的相关模型得到验证。