U-shaped Bend Numerical Simulation Of Springback Prediction And Optimization And Control,

Bending, which possesses a great proportion in sheet metal forming, is one of the most prevalent forming methods. Among stamping parts of automobiles a lot of parts are mainly produced by bending, for instance, carlines, cross rails and inner/outer plates etc. Springback is the inevitable phenomenon caused by elastic recovery and residual stress after sheet metal bending forming, and it influences the forming quality and latter assembly of part. Through more than ten years' researches and development, the current researches on springback prediction, measure, control and compensation are on a primary level. So it is significant to investigate how to find springback laws and values out accurately, and how to determine the structure of dies and select the stamping forming parameters and so on before designing moulds, which can reduce and control springback in sheet metal stamping processes. The combination of numerical simulation, orthogonal experimental method, ANN (Artificial Neural Network) and optimum technology is applied to investigate the springback prediction, optimization and control of U-shaped part bending in this paper, which can provide a new method to solve the springback problem, to improve the shape quality of the parts and to shorten the development period in practical production.The main contents of this dissertation are as follows:Key techniques of sheet metal forming and springback simulation are expounded such as finite element method, element type and mesh generation method, selection of element formula, contact algorithm and friction model, material model, springback simulation method. Furthermore, the modeling approach of springback numerical simulation is presented.The deformation process and springback of bending are discussed. A series of springback numerical simulation experiments of U-shaped part are carried out. The factors influencing sheet springback are analyzed in this paper, which include friction coefficient, binder force, sheet thickness and die gap etc. And then, the influence and notability of blank thickness, die gap, binder force and their two-factor interaction on bending springback of U-shaped part are studied by the orthogonal experimental design method. According to the analysis results of the orthogonal experimental design method, the key factors affecting bending springback of U-shaped part are optimized.Based on the numerical simulation experiments of U-shaped part bending, the prediction model of bending springback and blank thickness of U-shaped part is established by using BP neural network technology. The nonlinear relation between die gap, binder force and springback, blank thickness is fitted.Applied synthetically numerical simulation experiments, ANN and optimum technology, the springback optimization and control method of U-shaped part isexplored elementarily. Based on the study of bending springback of U-shaped part, springback optimization of U-shaped crashbox of vehicle body panels in product experiments is researched.The study on bending springback of U-shaped part can not only solve the springback problem like U-shaped parts, but also provide analyzing and solving methods to springback of complicated parts such as automotive panels.