Electromechanical Dynamics Analysis Of Multi-pass Roll-die Forming Machine

It is an effective way to realize lightweight of sheet metal by making high-strength steel to the variable cross-section beam products,which have better mechanical properties,such as lightweight,great rigidity and good stability.As a new type progressive forming equipment,the flexible roll-die forming machine can realize the precise variable section forming of high strength steel with the incremental rolls' and fixed die.In order to realize the cooperative motion control of multiple passes under heavy load,it is necessary to analysis the dynamic problems of multi-field coupling system with advanced high strength steel deformation,driving motors,transmission mechanism and roll-die system.In this paper,a new dynamic analysis method of the electromechanical system including advanced high strength steel deformation and five-step variable section roll forming machine is proposed by energy principle.The equipment equivalent simplified model is built by analyzing the structure composition,stress situation and moving process of the flexible roll-die forming system,and the system dynamics model is built by comprehensive considering the motors control parameters,advanced high strength steel type,machine design parameters,forming speed,dynamic load.The mathematical expression of each physical field's energy is deduced,and the system energy equation is obtained on the basis of energy conversion relationship.The dynamic equations of the system are presented by combining the system and motor energy equations.Deformation resistance is the necessary design parameters of the flexible roll-die forming machine,only by setting control parameters on the basis of steel dynamic deformation resistance in the stage of plastic deformation,the system can move normally according to the requirement.The simulation analysis of flexible roll-die forming process with five variable height part of quenched ductile steel QP980 was carded out by FEM software ABAQUS.The equivalent stress,equivalent plastic strain,roll forming force and torque were obtained and analyzed,the research provides reliable performance parameters for optimizing equipment performance.The value of dynamic differential equations' parameters was defined by theoretical analyzing.The equations were solved in MATLAB by writing solution program based on the fourth order Runge-Kutta method.The flexible roll-die forming system parameters such as servo motor current,rolls and frame moving speed and acceleration were obtained,the relationship between material deformation resistance,roll force,motor drive torque and each roll speed,acceleration is analyzed.The results obtained were applied to equipment development,and the high precision and variable height forming of QP980 steel is verified by test.The research has great significance of theoretical guidance to the design of flexible roll-die forming machine.