高速精密压力机闭式组合式预应力机身接触问题研究

Research on contact problem of close-combined pre-tightened frame in the high-speed precise press

为研究存在于高速精密压力机组合式预应力机身结构中的接触非线性问题,文章利用接触力学和有限单元法对该问题进行了描述和分析,论述了此类接触问题的增量理论和拉格朗日乘子法接触算法。为将机身作为一个系统来进行分析以确定预紧力,选择拉格朗日乘子法作为接触算法,并结合预紧力单元解决组合式预应力机身的有限元建模问题。利用预置条件共轭梯度解法对各预紧力工况下的机身模型进行求解,获得对应的应力-应变值,总结出预紧力-变形关系图,得出,为使压力机不产生间隙和错移,预紧力取值应为2000kN。数值分析结果和试验结果表明,分析可靠度为87.42%,采用接触单元结合预应力单元求解组合式预应力机身接触问题的研究方法,可用于高速精密压力机预紧力问题研究。

To research the contact non-linear states lying in the close-combined pre-tightened frame of high-speed precise press, the contact mechanics and the finite element method are applied to analyze in this paper. And the increment theory and Lagrange multiplier algorithm about the non-linear problem are illustrated. To research the frame as one system and find the congruous pre-tightening load, the finite element analysis models of combined frame are built up with selected Lagrange multiplier algorithm as contact arithmetic and applying pre-tightened force element. With applied the precondition conjugate grads solution, the stress-strain values corresponding different pre-tightened loads are achieved, and the relationship between pre-tightened forces and deformation are concluded. The results show that the appropriate pre-tightened force should be 2000kN to keep no clearance and excursion for this selected press. The 87.42% reliability indicates that the computed results correspond with the tested data, and the research method using the contact element and pre-press element to compute the contact problem of combined frame can apply to research pre-tightened force lying similar close-combined pre-tightened frame.