【摘要】 乘用车后保险杠在追尾和刮蹭等事故中将对车身产生保护作用,其刚度强度特性至关重要。针对某乘用车改性聚丙烯塑料后保险杠的刚度强度特性进行研究。首先通过试验测量保险杠材料的弯曲弹性模量和塑性应变曲线,然后利用Hyper Mesh创建该保险杠的有限元网格模型。在ABAQUS中完成接触等边界条件和载荷的定义,根据企业试验标准的要求对有限元模型进行刚度和强度的仿真分析,再利用台架试验进行验证,最后对刚度不达标的部位进行了改进设计。结果表明:所建立的有限元模型能较好地预测刚度强度性能;保险杠弹性特性在小变形状态近似为线性,在变形量达到20 mm以上时将呈现出明显的非线性特性;保险杠在大变形及回弹过程中表现出良好的恢复性能并能消耗一定的能量。更多还原

【Abstract】 The rear bumper of passenger car protects the body in accidents,such as rear-end and scratches,so the stiffness and strength are very important for a bumper. Therefore,the study on stiffness and strength of a modified polypropylene plastic rear bumper was carried out. First,the flexural elastic modulus and the plastic stress-strain curve were measured through experiments. Then the finite element mesh model of the bumper was created with Hyper Mesh. The boundary conditionsincluding interactions and the load were defined in ABAQUS. The stiffness and strength of the finite element model were simulated according to the test standards of the enterprise. The simulation was verified with bench test. Finally,the area which doesn’t reach the stiffness criterion in the mask was verified. The result indicates that the finite element model of the rear bumper predicts the stiffness and strength properties well. The elastic characteristic of bumper is nearly linear in the small deformation state,and the nonlinearity will be obvious when the deformation reaches 20 mm. During the process of large deformation and springback,good recovery capacity is performed and a certain amount of energy is consumed.更多还原