局部接触变形模型对简支梁多次弹塑性撞击模拟结果的比较

针对钝圆柱头刚性质量水平撞击理想弹塑性简支梁问题,比较分析了3种典型的局部接触变形模型,即弹塑性剪切变形(EPS)模型、Johnson钝楔压入(BI)模型和单轴压缩(UC)模型对可能出现的多次弹塑性撞击现象的模拟结果的影响.通过引入多次撞击和分离条件,将3种模型加以推广,并结合有限差分法,提出了求解多次弹塑性撞击问题的方法.通过对算例的比较可知,3种模型均可推广用于多次弹塑性撞击现象的模拟,它们对撞击力的模拟结果有差别,对撞击区的开始和结束时间等多次弹塑性撞击的分布特征的模拟结果则完全一致,对梁中端位移、刚性质量速度和梁上的应力等弹塑性撞击动力响应的模拟结果也完全一致.

Comparison of Simulation Results of Local Contact Deformable Models on Multiple Elastic-plastic Impacts of Simply Supported Beam

In view of the problem of an elastic perfectly-plastic simply supported beam impacted horizontally by a round-nosed rigid mass, the effect of the three local contact deformable models, the elastic-plastic shear deformation(EPS) model, the Johnson's blunt indentation(BI) model and the uniaxial compression(UC) model, on multiple elastic-plastic impacts between a round-nosed rigid mass and a simply supported beam is investigated. By introducing the conditions of multiple impacts and multiple separations and using the finite difference method, the three local contact deformable models are extended to simulate multiple elastic-plastic impacts phenomenon. The simulation shows that the EPS model, the BI model and the UC model can be applied to simulate the multiple elastic-plastic impacts phenomenon. Although the three models have differences in the simulations of impact forces, the simulations of the distributions of the impact forces, such as the beginnings and the endings of the impact zones, are in good agreement each other. In addition, the simulation results of the dynamic responses of multiple elastic-plastic impacts, such as the displacement of the beam's mid-point, the mass velocity and the beam stress are also in good agreement.