Research On Curvature Error Compensation Technology Of Roll Bending Of Aluminum Alloy Profile

Aluminum alloy profile has the characteristics of light weight and high specific strength,and it is widely used in aviation field.The bending part of aluminum alloy profile is an important part of the main bearing structure of aerocraft,and its forming precision will directly affect the assembly quality and aerodynamic performance of the aircraft.The bending parts of aluminum alloy profile are mainly formed by rolling bending process.The forming process has many problems such as large rebound and complex deformation process,which makes the forming accuracy difficult to control.Therefore,it is necessary to study the rolling process and precision compensation technology of the profile.Based on the four-roll bending machine,the mathematical models of constant curvature and variable curvature roll-bending was modified.The curvature error compensation method is proposed.The forming accuracy can meet the design requirements gradually by iterative compensation.The feasibility of the error compensation method was verified by finite element simulation and roll-bending test.The specific research work is as follows.(1)Based on the analysis of the distribution of elastic-plastic deformation region in the profile during the rolling process,the mathematical model of four-roll roll-bending process was modified,and the theoretical model precision of the rolling process was improved.(2)Taking curvature as the iterative compensation parameter,the mathematical model of curvature error iterative compensation was established.The key node control method of the roll forming with variable curvature and the measures to modify the parameters of the rolling process were proposed by iterative error compensation of the curvature of the key nodes.(3)The finite element model of rolling bending of constant curvature and variable curvature profile was established,and the simulation experiment of rolling process was carried out.The simulation results showed that the forming accuracy was improved by error compensation,and the iterative convergence of error compensation model and the accuracy of error compensation theory were verified.(4)The roll-bending test of aluminum alloy profile with constant curvature and variable curvature was carried out.The bending test of aluminum alloy profile was carried out by using T-section and L-section respectively.The convergence of curvature error compensation was verified according to the constant curvature test results.In the roll-bending test with variable curvature,two kinds of target profiles with variable curvature were established.The results showed that after one or two error compensation,the forming results converge to the target value gradually,and finally meet the accuracy requirements.The feasibility and universality of curvature error compensation method in the accuracy control of roll forming were verified,and the quality and efficiency of roll forming were improved.