Effects of changing environment and loading speed on mechanical behavior of FRP composites
Effects of changing environment and loading speed on mechanical behavior of FRP composites
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DOI：
10.1177/0731684406059783
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发表时间：
2006-01-01
影响因子：
3.1
通讯作者：
Ray, B. C.
中科院分区：
文献类型：
--
作者：
Ray, B. C.
纤维增强聚合物复合材料(FRP)的耐久性受其组成成分(增强纤维、树脂基质和界面状态)的耐久性控制。大量的研究集中在评估纤维基复合材料的界面结构与性能之间的关系。由于增强相和母相之间的热膨胀系数不同，应力集中出现在界面区域。环境引起的基质和纤维降解的严重不匹配导致了FRP复合材料中局部应力场和应变场的演化。研究了改变湿热循环(通过改变相对湿度(RH)并保持温度不变，或在保持RH不变的情况下改变温度)对不同质量分数玻璃纤维增强环氧/聚酯复合材料的吸湿/失湿动力学和层间剪切强度(ILSS)的影响。将力学评估扩展到评估玻璃/环氧湿热冲击和玻璃/聚酯层合板在2 mm/min和50 mm/min十字头速度下的加载速率敏感性。吸附/脱附动力学的观察结果取决于湿热冲击循环的性质和纤维增强的质量分数。机械性能的结果在条件作用的不同阶段有统计学意义。研究发现，在所有情况下，十字头速度越高，剪切值越大。观察到机械响应取决于基质树脂和湿热冲击循环的类型。很少有文献公开阐述聚合物复合材料与这种现实环境情况的重要相互作用。
Durability of fiber reinforced polymer composites (FRP) are controlled by the durability of their constituents: reinforcement fibers, resin matrices, and the status of interfaces. A great deal of research has been focused on attempting to assess the relationship between interfacial structure and properties of fiber-matrix composites. It is at the interfacial area where stress concentration develops because of differences in the thermal expansion coefficients between the reinforcement and the matrix phase. A significant mismatch in the environmentally induced degradation of matrix and fiber leads to the evolution of localized stress and strain fields in the FRP composite. The present investigation aims to study the effects of changing hygrothermal conditioning cycles (either by changing relative humidity (RH) and keeping the temperature constant, or by changing the temperature while RH the same is maintained) on moisture gain/loss kinetics and on interlaminar shear strength (ILSS) of varied weight fraction glass fiber reinforced epoxy and polyester matrices composites. The mechanical assessment is extended to evaluate the loading rate sensitivity of hygrothermally shocked glass/epoxy and glass/polyester laminates at 2 and 50 mm/min crosshead speeds, respectively. Observations on absorption/desorption kinetics are noticed to be dependent on the nature of hygrothermal shock cycle and on the weight fraction of fiber reinforcement. The results of mechanical performance are statistically significant at different stages of conditioning. Shear values are found to be greater at higher crosshead speed for all undertaken situations. Mechanical responses are observed to be dependent on the matrix resin and the type of hygrothermal shock cycle. Very little and limited literature is open to address the important interactions of polymer composites with this kind of realistic environmental situation.