Development Of As-quenched Sheet Metal Rubber Forming Mold Automatic Compensation System

With the application of digital technology in modern manufacturing industry,the manufacturing information carrier of sheet metal parts,which accounts for half of aircraft body structure parts,has gradually changed to digital quantity.Aiming at the springback problem of rubber forming,the automatic compensation system of die surface is developed in CATIA software by using computer aided geometric modeling technology,and the forming die is optimized by digital operation of compensation system.At the source,the precision of sheet metal parts is guaranteed,and the forming quality and efficiency are improved.The mechanical properties of the aluminum alloy material in the as-quenched state were tested.The connection between the material database and the automatic compensation system of aircraft rubber-formed sheet metal die based on CATIA was established by using ADO access technology.The database of mechanical properties parameters of the aluminum alloy material in the as-quenched state was established in the system,which solved the problems of insufficient material manual parameters and CAD/CAE material model in digital design and production of aircraft sheet metal parts.The category and structure technology of rubber-formed sheet metal part are analyzed,and several kinds of springback compensation structure types of sheet metal parts developed are defined.Through the analysis of sheet metal stress,bending moment calculation and springback calculation of rubber bag forming,the theoretical algorithm of springback compensation is obtained.The springback compensation theory of various bending and subsidence is applied to the automatic compensation system of die by using curve method and plane cutting compensation method.Based on the CAA development technology and the compensation principle of various bending springback,an automatic compensation system for rubber bag forming die was developed under CATIA environment.Eleven modules including springback compensation for bending and sinkage were developed in the system.The springback compensation of five kinds of forming dies for a certain type of aircraft was carried out by using the developed system,and the compensated die digital models were obtained.Finite element simulation of sheet metal forming was carried out by using compensated die digital die,and Q235 steel was used to make the die according to the numerical simulation.The sheet metal parts meeting the standard were obtained in one forming test,which verified the accuracy of the compensation system.It plays an important role in simplifying the process of die design and trimming,improving the quality of aircraft sheet metal parts and saving the development cost.