Design And Verifica Tionof The Parametricsimula Tionprogram For Multi-Pointforming Based On APDL

Multi-point forming is a new kind of die-less sheet metal forming technologywhich could forms the required surface shape by means of height-adjustable punches.The pre-forming simulation has to be done to predict the forming result due to theimmaturity about this technology.Two difficulties exist in the finite element analysis of multi-point forming: thecomplicated modeling process and the difficulty to control the movement pattern ofmore punches simultaneously. Based on the idea of the parametric design method,ANSYS parametric design language (APDL) provides a powerful tool for theparametric finite element analysis of multi-point forming by using intelligent analysismethod.The rapid modeling is realized by use of the parameter input dialog box providedby APDL for all parameters such as that of the forming sheet, the punch, the materialproperties and the forming load. The calculation program for the original position ofeach punch is designed by the application of expression and function, branch andcirculating provided with APDL, and then the stroke of each punch under differentmulti-point forming modes is determined. The process of model definition, loading andanalysis is controlled by customized multi-point forming toolbar which is conductedthough the usage of APDL macros and user program function.The numerical simulation of cylindrical surface, spherical surface and hyperbolicparaboloid are completed by the designed parametric simulation program for multipointforming. And the quality evaluation index for multi-point forming is established inthis paper.The optimal forming force for cylindrical surface, spherical surface and hyperbolicparaboloid in different radius and thickness are determined according to the qualityevaluation index, and the influence of radius and thickness on the optimal forming forceare studied. The influence factors and laws of indentation, wrinkling and springback arealso studied.Finally, the forming experiments for cylindrical surface, spherical surface andhyperbolic paraboloid with the force-displacement separated control forming method arecompleted according to the simulated correction data under the optimal forming force.The results indicate that: there is a deviation between simulated and experimental data,but the deviation is produced by the difference of the forming force in the simulation andexperiment. So under this consideration, the needs of engineering application can bemet by the designed program.