铸造型砂密实过程的数值模拟

NUMERICAL SIMULATION FOR SQUEEZE PROCESS OF CASTING SAND

基于试验数据,研究铸造型砂的耦合力学行为,并进行密实过程的数值模拟。建立了型砂瞬时材料模量与应变之间的耦合关系,针对压实过程中瞬时材料模量逐渐增加这一非线性特征,在有限元分析平台上,引入中间变量,提出了相应的直接显式计算方法。研究了紧实率、粘结剂等材料参数对型砂密实过程中应力应变分布的影响;考虑几何、接触等非线性因素,研究了模样角点的应力分布特征。并将计算结果与试验值进行比较。

The accurate simulation analysis for squeeze process of sand in casting is still a difficult point since the complex nonlinear constitutive equation of sand. Based upon experiments of squeeze process of sand, the relative coupling behaviors and numerical simulation are focused. Some researches cover: simulating platform of transient coupling stress-strain relationship, explicit algorithm for nonlinear behavior of sand, the influence to stress-strain distribution of the material parameter variation, contact friction, the arch bridge phenomena occurring in mould casting, which all are investigated numerically. All calculated results are compared with experiments.