动态镦粗过程的动力显式有限元分析

为了研究金属的三维动态锤锻成形过程,基于连续介质力学及有限变形理论,建立了一种有限元模型.采用动力分析方法,在运动方程中加入惯性力项考虑锤锻中显著的惯性效应;根据设备的工作原理按照能量守恒定律计算变形期间的锤头速度;同时,将变形视为一个绝热过程计算变形期间试样内部的温度升高.基于建立的模型开发了动力显式有限元分析程序,模拟了铅块试样在落锤打击下的动态镦粗过程,给出了试样内部的位移、等效应变、等效应力和温度分布规律.将变形后试样几何形状、成形载荷-时间曲线和锤头速度-时间曲线的计算结果与实验结果相对比,表明了开发程序计算结果的准确性.

Dynamic explicit finite element analysis of dynamic upsetting process

In order to study the three-dimensional dynamic hammer forging process of metal,a finite element model has been established based on the continuum mechanics and finite deformation theory.A dynamic analysis method was used,and the inertia force was introduced in the equilibrium equation to analyze the inertia effect which is obvious during the hammer forging.According to the operating principle of hammer equipment,the hammer velocity during the deformation process was calculated by the energy balance equation.The temperature rise in the specimen was calculated by the adiabatic principle.With this model,a dynamic explicit finite element analysis code was developed.The dynamic upsetting process of lead block specimen at a drop hammer machine has been simulated.The X-displacement,equivalent strain,equivalent stress and temperature distribution in the specimen were obtained.By comparison between the experimental and calculated deformed geometry,forming load-time curve and hammer velocity-time curve,the accuracy of the calculated results of the code was verified.