The Study On Plastic Deformation Of Steel Plate During Rolling And Bending Process

In this paper, the thick plate are simulated numerically under bending and uniaxial tension by using the elastic-plastic theory and finite deformation theory, and the deformation of model and plastic instability of material are mainly analyzed.In the engineering field, how to describe and analyze partial plastic instability and the critical state of plastic instability is concerned greatly. The mechanics description and mechanic field of material at large strain should be given since the critical state of plastic instability occurs only when plastic strain becomes some value. In the paper, some decarbonized steel is researched by using the constitutive relation based on solid cylinder torsion test.The mechanics progress of the thick plate is simulated numerically and two kinds of models with different thickness and different curvature radius of pressure head cushion are discussed respectively. By the aid of the strain-load curve of studied points, the change of mechanics field of model is discussed and critical state of plastic instability is derived. At last, we analyze the results of all these cases, and discuss the effect of the parameters of plate on the rule of plastic instability. The conclusions obtained from this paper are: the plastic instability is not very sensitive to the curvature radius of pressure head cushion, and the value of critical plastic strains under bending are relative with one under the uniaxial tension. The research shows that for the engineering plastic material with smaller plastic harden modulus, it is necessary that suitable parameters on strain is chosen to describe the critical state of plastic instability instead of the parameters on stress because the parameters on stress is not sensitivity to the progress of strain change.