Research On Metal Bar Instantaneous Rebound In Two Cross-Roller Straightening Process

Metal bars have many applications in aerospace,automotive,marine and other industries.According to different usage requirements,People use different states of the bar in different situations.Sometimes there are certain requirements for the straightness of the bar.Since the bar can not meet the required precision after a single processing.At this time,the bar should be straightened.Due to elastoplastic deformation during bar re-straightening,Therefore,the prediction of the rebound of the bar has caused great trouble.In order to accurately predict the instantaneous rebound of the bar during the straightening process,The basic properties of the bar,the bending law and the stress-strain analysis are very important.The main contents of this paper are as follows:Establish an ideal elastoplastic model,Analysis of the stress-strain of a metal bar under bending conditions,Analying the relationship between the curvature change of the bar and the deformation of the bar.Based on an elastoplastic reinforcement material model,In several aspects that affect the rebound of the bar,Studing the elastic curvature of the bar in terms of the initial bending of the bar,the neutral layer offset of the bar and the bar bending rate.Establish a curvature ratio,Determine the relationship between the curvature ratio and the bending radius and bending moment.Provides a prerequisite for establishing the curvature equation and bending deflection.Not only the elastic curvature of the bar relates to the self-parameter of the bar material.In this paper,considering the influence of neutral layer migration on the elastic deformation zone and plastic deformation zone of bar when analyzing the complex curvature of bar.More in line with the actual model of bar straightening,Relative to the calculation of other elastic curvatures,Adding the influence of the neutral layer offset on the complex curvature of the bar,and the calculation of the complex curvature is more accurate.Analysis of the neutral displacement of the bar during straightening and back-bending of the bar,Determine the effect of the neutral layer offset and the radius of the elastic core on the complex curvature of the bar.