Abstract In the present study, the interfacial behavior of overmolded hybrid fiber reinforced polypropylene composites (hybrid composites) in the working temperature range from 23 °C to 90 °C was studied by experimental and constitutive methods. Monotonic and cycle loading-unloading single-lap-shear tests were employed to determine the interfacial properties of hybrid composites. The experimental results show that both interfacial shear strength and shear stiffness decrease with increasing working temperature. A regression function was adopted to evaluate the decaying degree of interfacial properties with increasing working temperature. The shear stress-displacement relationship under monotonic loading exhibits nonlinear behavior after an initial elastic region. The envelope lines of shear stress-displacement of hybrid composites under cyclic loading indicate that the nonlinearity in the curve is caused by the plastic deformation of polypropylene in the interphase region. A constitutive model was built to describe the nonlinear shear stress-displacement relation of hybrid composites at different working temperatures. A full suite of temperature-dependent plastic parameters in the model was obtained from cyclic loading-unloading tensile tests. The predicted shear stress–displacement curves agreed well with experimental results from different working temperatures. In addition, the failure mode of hybrid composites varied with working temperature.

中文翻译：

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工作温度对包覆成型混合纤维增强聚丙烯复合材料界面行为的影响

摘要 在本研究中，通过实验和本构方法研究了包覆成型的混合纤维增强聚丙烯复合材料（混合复合材料）在 23 °C 至 90 °C 工作温度范围内的界面行为。采用单调和循环加载-卸载单搭接剪切试验来确定混合复合材料的界面性能。实验结果表明，界面剪切强度和剪切刚度都随着工作温度的升高而降低。采用回归函数评价界面性质随工作温度升高的衰减程度。单调载荷下的剪切应力-位移关系在初始弹性区域后表现出非线性行为。循环载荷下混合复合材料的剪切应力-位移包络线表明曲线中的非线性是由聚丙烯在相间区域的塑性变形引起的。建立了一个本构模型来描述不同工作温度下混合复合材料的非线性剪切应力-位移关系。模型中一整套与温度相关的塑性参数是从循环加载-卸载拉伸试验中获得的。预测的剪切应力-位移曲线与不同工作温度的实验结果非常吻合。此外，混合复合材料的失效模式随工作温度而变化。建立了一个本构模型来描述不同工作温度下混合复合材料的非线性剪切应力-位移关系。模型中一整套与温度相关的塑性参数是从循环加载-卸载拉伸试验中获得的。预测的剪切应力-位移曲线与不同工作温度下的实验结果非常吻合。此外，混合复合材料的失效模式随工作温度而变化。建立了一个本构模型来描述不同工作温度下混合复合材料的非线性剪切应力-位移关系。模型中一整套与温度相关的塑性参数是从循环加载-卸载拉伸试验中获得的。预测的剪切应力-位移曲线与不同工作温度下的实验结果非常吻合。此外，混合复合材料的失效模式随工作温度而变化。