树脂基三维机织复合材料拉伸失效模式研究

树脂基三维机织复合材料试件在拉伸过程中,较多试样出现两个断口,其中一个断口出现在夹持过渡段,且呈明显的压缩失效特征。采用显式有限元计算及应力波理论分析方法,对试件断裂后的瞬态位移及应变响应开展了研究,结果显示拉伸断裂后应力波在远端夹持端引起的压缩应变大于静态压缩失效应变,从而导致在夹持端发生二次失效。该结论对采用ASTM D3039开展三维机织复合材料拉伸试验时的有效破坏模式提出了修正建议。

TENSILE FAILURE MODE INVESTIGATION OF POLYMER MATRIX 3D-WOVEN COMPOSITE

Two fracture locations were normally observed on the tensile specimens when polymer matrix 3D-woven composites were tested under uniaxial tension.Moreover,one of the fracture locations was mostly at the gripping area and appeared to be compressive failure.With the use of explicit FEA and stress wave theory,the displacement and strain of the specimen after failure were studied.The result shows that the compressive strain caused by the stress wave at the gripping area was higher than the static compressive failure strain,which caused the fracture at the gripping area.This result provides insight into the failure mode discovered when using ASTM D3039 standard for obtaining the tensile properties of polymer matrix 3D-woven composites.