Analytical And Experimental Study On Springback Of Continuous Curvature Plane Bending

The products formed by bending process with advantages of good service performance and high dimensional accuracy,are widely used in medical,automobile,ship and nuclear power industries.In recent years,with the increasing application of variable curvature parts in industry,enterprises put forward higher requirements for forming process and product quality.In this paper,a new iterative compensation method for continuous curvature bending process is proposed,which has certain generality for solving the springback problem.This theory aims at making the size of the forming part reach the expected value through finite compensation,taking curvature as iteration parameter.And then,the Springback Control and prediction of continuous curvature free bending process are completed.Based on establishing this iterative compensation mechanism,the convergence of curvature iteration in general free bending process engineering application is verified by combining simulation with experiment.The bending process of 304 stainless steel and ST12 cold-rolled steel with different function equations is modeled.The curvature change is tracked and iterated by using the relevant knowledge such as "numerical analysis".Taking the fitting of least square method as the verification condition,two models with polynomial and exponential function types are analyzed and proved.In this paper,a two-dimensional stress-strain model of cantilever beam type is established by finite element software Abaqus,and the bending process is simulated based on the iterative compensation mechanism mentioned above.The simulation results show that after each iteration compensation operation,keeps pace with the theoretical results,whether for curvature of a point at the micro level or the overall shape trend at the macro level.With the increase of iteration compensation times,the parameters of forming parts gradually approach the expected value and converge to the target value within the accuracy range.Finally,it is verified by the bending experiments on these four models that the feasibility of curvature iteration compensation mechanism in continuous curvature plane bending process.Some of these models are selected to illustrate the advantage of this iterative mechanism.It is not limited by material types and mechanical models,meaning this iterative mechanism has the characteristics of universality.