基于流变学模型的铸钢试件三维热应力数值模拟及热裂机理研究

3D Numerical Simulation of Thermal Stresses of a Cast Steel Specimen by Rheological Model and Analysis of the Mechanism of Hot Tearing

建立了铸件凝固过程热应力模拟的三维流变学本构方程及其有限元算法和基于流变学模型的ＦＤＭ／ＦＥＭ 集成的三维应力应变分析系统。对带热节的铸钢试件在不同约束条件、不同浇注温度、砂型初始温度及受阻长度等情况下进行了数值模拟，进而研究了这些因素对热裂趋势的影响。研究结果表明粘塑性应变是热裂产生的主要因素。

A 3D rheological model and its algorithm for finite element method were established and a FDM/FEM integrated analysis system of thermal stress-strain based on this model was built. A cast steel specimen designed for hot tearing was simulated under different constraints and different pouring temperatures, initial mold temperatures and retarded lengths as well. The effects of these factors on the hot tearing tendency were investigated. The simulation results show that the visco-plastic strain plays significiant role in the occurrence of hot tearing.