汽车仪表盘PP材本构关系计算

Constitutive model inversion and calculation of PP material for vehicle dashboard

利用PP材料拉伸试验的位移载荷曲线,结合弹塑性力学中的相关假设,分阶段计算该材料的真应力-真应变曲线,并利用LS-DYNA显示分析算法,输入该真应力-真应变曲线,模拟计算该材料的单轴拉伸试验,通过模拟结果与试验结果的比较,验证了真应力-真应变曲线的有效性。同时提出了一种塑性材料颈缩阶段的本构简化模型。

Using the load-stroke curve of material tensile test of Polypropylene, combined with related hypothesis in the mechan- ics of elastic-plastic, the true stess-strain curves are calculated according to different phase. Inputting the true stress-strain curves, the uniaxial tensile tests of this material in different strain rate are simulated by LS-DYNA explicit integration algorithm. Through the comparison of the simulation result and test result, the effectivity of the true stress-strain curves are confirmed. At the same time, a new simplified constitutive model of the necking phase of the plastic material is adopted.