Prediction Model Of Curvature Radius Of Symmertrical Four-roll Coiling Circle

Plate bending machine has experienced the development process from two rolls to three rolls and then to four rolls.At present,the technology of four-roller plate bending machine is quite mature.The four-roller plate bending machine frequently used includes side roller straight line and side roller arc type plate bending machine.However,the research on the symmetrical four-roller bending machine is still relatively small.Due to the special structure of the symmetrical four-roller bending machine,it can be reversed during operation,which greatly reduces the amount of remaining straight edges of the formed part.In the mass production process,materials can be saved and economic efficiency can be improved.The theoretical model of the existing symmetrical four-roller bending machine has a large error,which is of little significance to the actual production process.Therefore,this paper gives a new curvature prediction model solution method,which reduces the theoretical value and the actual value.The error of the forming result provides a new idea for predicting the radius of curvature of the forming part in actual production.The main research contents and conclusions of this paper are as follows:Based on the small curvature plane bending spring-back theory and the bilinear hardening material model,the spring-roll reduction process is analyzed to obtain the relationship between the reduction amount and the radius of curvature after spring-back.The rolling range of the plate is determined by the plastic deformation of the plate and the limit reduction of the plate bending machine.The theoretical calculation of the relative reduction and the relative curvature in this range show a good linear relationship.Based on the finite element simulation software ABAQUS,a symmetrical four-roller winding simulation model was established,and the relationship between the relative reduction and the relative curvature at different friction coefficients and speeds was compared.The results show that the friction coefficient and rotation speed have little effect on the relative curvature.When the friction coefficient is 0.18 and the rotational speed is 0.1 rad/s,the numerical simulation results show a good linear relationship between the relative reduction and the relative curvature.Two materials of ST12 and aluminum alloy 1060 are used for the rounding experiment.When measuring the radius of curvature of the formed part,the method of multiple measurements and averaging is used to reduce the error in the measurement.The experimental results are compared with the finite element results to verify the limited The correctness of the meta-algorithm.Comparing the finite element results with the theoretical calculation results,the curvature prediction models of different materials are solved according to the relationship between the data,and the solution method is given.This method is applied to solve the prediction model of Q235 material,and the relative reduction and relative curvature relationship under other spans are predicted.The results show that the maximum relative error between the prediction results and the finite element simulation results is less than5%,which meets the requirements of engineering production,and further proves the correctness of different material prediction models.