Study Of The Rules About Hole Flanging And Warping Of Webs

Aluminum alloy web is one of the main structures about the aircraft.Studying the formability of aluminum alloy sheet under heat treatment,provides not only more theoretical basis for improving process and product optimization,but also more accurate mathematical models for numerical simulation of various stamping types.Round hole flanging forming is an important forming process among many sheet metal forming.The quality of the process and controls,which is a direct impact on the final part of the forming quality and accuracy,especially the control of rebound and shape warp,and is also related to the structure of the product and the effect of assembly.This topic mainly explores rebound and board warping after the flange flanging.Based on the single-pull test,the parameters of forming properties about 2024 and 7075 aluminum alloy sheets under new quenched condition are obtained.The orthogonal test is used to select the types of test programs.The finite element method of PAM-STAMP is used in combination with the principle of sheet metal unfolding.The typical web parts are simulated by round hole flanging forming,unloading and rebound process,and the influencing factors on springback and surface warping after part forming are predicted.Then the shape warping rule and its mechanism are obtained.According to the four possible factors,the rules are generalized and compared.The factors are hole diameters,flange heights,flange fillet radius and rubber-sheet friction coefficients.The correctness of the FEM simulation results is verified by the forming process test.The measured results of the formed part are in good agreement with the results of the finite element analysis.Combining with the above research methods,the conclusion obtained is of great significance to the process of punching production process of the round hole flanging.This kind of sheet metal parts of the aircraft web,which is of great helpful to the quality improvement,efficiency improvement and cost reduction of the product forming.