FE Simulating And Technics For Forming Of Large Thick Cylinder

This article adopts the finite element numerical simulation method,and combining the shaping characteristic of metal high temperature plasticity,and had detailedly discussed just the basic theory of viscoplasticity finite element method and deals with the method,the derivation has been gone out to based on that the type is arranged in the finite element of viscoplasticity having punished the function law and the heating power coupling crossing the stress model just,and built at the beginning of finding the solution the approximate general letter of velocity field,and led out to find the solution the equation.According to mentioned above finite element theory and the processing technology,combining the engineering application,is directed against the thick wall tin shape forging warms to draw deeply,built the heating power coupling finite element model of viscoplasticity just,the advance side by side line analog computation. Analysed metal stress and meets an emergency and load,temperature field and the neck down defect and forming technique and prefabricates base ready to be machined into a finished product size,mould size and become cool the relation of condition,and put forward eliminating the neck to contract the settlement scheme of defect,and gave out forming technique that optimizes and his to imitate at last.Doing some active explores of hot drawing technics and FE simulation for thick cylinder in this article,and can reach the following conclusion:(1)Once drawing to be close to the limit drawing coefficient,and the effective stress of section of wall surpassed tensile strength,and will give rise to the neck down.(2)Adopt the difference in temperature to draw and effectively to raise a wall bearing capacity deeply,and reduces the neck down.(3)The utilization heat exchange boundary conditions is set up successfully,and built the water-cooling model,and imitates the result to indicate that the establishment of model is correct. There is the very big guidance meaning to the similar finite element builds the pattern.(4)Adopting two times drawing the technology scheme,and can enlarge drawing coefficient,reduce the base becoming deformed the level,and reduces the internal stress which received,hopefully eliminating the neck down.(5)Concave die circle horn radius or relatively concave die circle horn radius is verybig to a section of thick change of the wall influence relatively must cause attaching importance to.