Model Element Method And Metal Plastic Simulation

Current metal plastic theories are insufficient to explain real problems. The results of finite element method are all numerical, which are lack of physical meanings in comparison with analytic solutions. So it is difficult to show corresponding relationships between parameters inner researching objects and the laws of their mutual effects; the application of upper bound element technology by oneself gives only an upper bound, but a real solution, which greatly restricts its applications. To change this, a new analysis method 'model element method' is proposed by us. Model element method firstly divides the object in several characteristic time sections, and then each time section is divided into some model elements by space field, which is described by the proper model elements. The model element method includes both finite element method and upper bound element method and can compensate each to other.According to the basic theory and the method and steps of the solutions of plastic forming problems, this article proposes a kind of model element. This model is the plane distortion problem, which workpiece and die's interface is plane and two-side of interface is free surface. This article applies slide-line method to solve model element and give a simple introduction, because slide-line possesses merits of geometric visualization and conformation of plastic field and rigid field.This article make quantitative descriptions about mechanical characteristics of model: confirmation of geometry shape and size of model; confirmation of stress field expression of model; confirmation of displacement field expression of model; confirmation of distortion force distributing along the direction of breadth. According to the relation between b/h and L, the model plastic filed is divided into three kinds of types as following: general plastic field, sub-general plastic field, and over-general plastic field. The stress field is divided into three sections that are exactly described. Distortion force distributing along the direction of breadth is a kind of function about b/h.This article proposes a function of L,δ, ω during the course of descriptions of mechanical characteristics of model that establish strong base of material solutions of plastic field and slide-line field. Meanwhile this article makes universal conclusion about model mechanical characteristics and model element use abroad.