Research On Key Process Parameters Of Hydroforming Of Complex Surface Parts Based On Numerical Simulation

Today,many sheet parts due to structural complexity and material forming performance and other issues,can't be forming once time.The product quality is poor and the pass rate is low.And easily lead to permanent damage to the material.Plate filling process is a new flexible manufacturing technology,can greatly improve the parts of the forming accuracy and production efficiency.Complex surface parts in the plastic forming because of its complex stress and strain,the use of ordinary forming method prone to instability phenomenon,residual stress is not uniform,affecting the fatigue strength of parts.Therefore,through the liquid filling technology can improve the sheet forming performance and forming quality.In this paper,the car fender plate parts as the object of study,fender plate single plate parts were ladder-like,complex surface,forming easily lead to negative angle,deep drawing ratio is relatively large,forming difficult.Taking into account the liquid chamber sealing and plate stress characteristics,in the filling and deep drawing,the parts are designed in a symmetrical form and the design of the surface of the material surface,can effectively improve the forming effect.Through the numerical simulation method,the deformation mechanism and forming defects of the fender plate at the time of filling and drawing are studied deeply.Dynaform software dynamic display algorithm was used to analyze the different forming process of the fender plate and the forming effect under the conditions of different expansion pressure,liquid chamber pressure loading path,variable blank holder force,blank holder gap and friction coefficient.The plate was analyzed in different process,the wrinkling law,the rupture rule,the wall thickness distribution law and the strain law in the forming process.Through the comparison,analyze the forming effect between the general forming process and Hydraulic forming.Based on the FLD chart and the thickness cloud diagram of the part,the wrinkling law,the rupture rule,the wall thickness distribution law and the local special strain law under the different forming conditions were analyzed.Finally,the influence of different forming methods and different forming parameters on the forming effect of the plate is obtained,and the forming conditions of the filling and drawing of the fender plate are summarized.