考虑纤维方向分布的玻纤增强PP复合材料拉伸性能

纤维方向及其分布对玻纤增强PP复合材料的力学特性具有至为关键的影响。提出了一种快速获取纤维数量及每根纤维方向的方法。通过引入方向张量, 利用Moldflow软件进行玻纤增强PP树脂注塑成型模拟获得纤维方向的平均分布, 结合显微方法观察判断特定点的纤维沿厚度方向的分层情况及定量判断纤维方向的分布。对轿车玻璃纤维增强注塑仪表板的纤维方向相对一致处取与纤维方向呈0°、45°、90°的样条, 通过拉伸实验测得拉伸模量, 利用所提出的方法研究了仪表板内玻纤方向的分布及其对拉伸模量的影响。研究结果表明: 玻纤增强注塑仪表板的力学性能是各向异性的, 其沿厚度方向纤维按方向大致可分为三层。

Tensile properties of glass fiber reinforced PP composite considering fiber orientations

Fiber orientation and distribution are the main factors affecting the mechanical properties of fiber reinforced PP composite. This paper presented an approach for predicting the number of fibers and each fiber's orientation. By introducing fiber orientation tensor, the average distribution of fibers in the glass fiber reinforced PP resin composite was acquired through injection molding simulation with Moldflow. Quantitative fiber distribution and orientation along thickness at specific spots were obtained by metallographic method. The proposed approached was demonstrated by a car instrument panel made from injection molding of thermoplastics with glass fibers. Tensile test samples were cut from the instrument panel with an angle of 0°, 45°, 90° to the fiber direction at sites where fibers were highly aligned. The tensile moduli were obtained through tensile tests. The fiber orientation distribution and its effect on the tensile modulus were investigated by the proposed method. It is shown that the car instrument panel is heterogeneous in mechanical properties. The fibers are roughly distributed into three layers along the thickness direction with each layer having aligned fibers.