Theoretical Calculations And Fem Analysis Of Seven-Cross-Roller Bar Straightener

In pace with the development of China's national economy, bar production is playing an increasingly important role in industry construction. Bar straightening technology to a large extent determines the level of product quality. Due to the lack of theoretical guidance, the determine of parameters in bar straightening process relies mainly on practical experience, which often results in instability of the quality, and makes negative impact on industrial manufacture. Based on the straightening principle of seven-roller straightening machine, the straightening process is researched by the method of combining theoretical calculations and computer finite element method (FEM), to guide the actual production.In the process of researching bar straightening technology, related theories are involved in elastic-plastic theory, mechanics of materials, FEM method and numerical analysis methods.This paper summarizes the development of straightening theory and straightening technology at home and abroad. Based on metal elastic-plastic theory, this paper analyzes the straightening process of seven-cross-roller straightener, studies the bending deformation and bending moment of the bar, studies the straightening force of each roller, and derives the mechanical model of straightening force. It also discusses design method of the profile of roller, the principle of parameters selected such as roll distance and tilt angle. The method of calculating pressing down displacement is given in this paper. After analyzing the straightening theory, Matlab language is applied to write visualization software, which enables users to simply enter the basic parameters to get the values such as the bar's pressing down displacement,the profile of roller curve and so on.On the basis of theoretical analysis and numerical calculation, this paper applies FEM software ABAQUS to establish a model of seven-cross-roller straightener, calculates and soles the FEM model, studies the FEM simulation results, analyzes bar variation of stress and strain, verify the reliability of theoretical calculations.