复合材料高温强度测试分析及数值模拟

Test and Numerical Simulation of Failure Strength for the Composite Material at High Temperature

对碳纤维环氧树脂复合材料T300/AG80的力学性能进行了测试与计算。采用QBT-70-400x高低温测控系统与万能试验机相结合,得到了材料在不同温度下的拉伸破坏强度和有效弹性模量,分析了温度对材料力学性能的影响,并结合试件破坏断口形貌分析了试件的损伤模式及破坏机理。以试验所得纵横向有效弹性模量为基础,参考其它实测热物理参数,用有限元方法对试件拉伸过程进行了数值模拟分析,将计算结果与试验结果相对比,数据基本吻合。分析试验和数值结果可知,温度升高所带来的温度应力和环氧树脂软化分解是材料力学性能下降的主要原因,但受温度影响的试件破坏模式的差异对材料力学性能的影响也很明显。

Mechanical properties of the composite T300/AG80 are tested using temperature measure and control system QBT-70-400x and general test machine at different temperature. The effective elastic modulus and tension failure strength of the composite are obtained. Effects of temperature on mechanical properties of the material are analyzed. Damage mode of specimens and failure mechanism of the composite are also analyzed by fracture morphologies. The model of numerical simulation is set up, the effective elastic modulus come from the experimental assessment and physical property parameters of high temperature come from the references. Tension failure strength of the composite are obtaines and compares with experimental result. The result of numerical simulation is consisted with that of experimental ones. The numerical simulation and experimental result show that the decomposition of epoxy is the main reason for the descent of mechanical properties of the composite, but the different fracture morphologies affected by temperature is also important reason.