Study On Parameterization Of Incremental Sheet Forming Path Of Conical Parts

Conical part is one of the most typical parts of Incremental sheet forming process (ISF). At present, the forming paths of conical parts whose forming angle is greater than the limit forming angle are not studyed deeply. The study on parameterization of the forming paths of conical parts can shorten the desgin time and also have an important meaning of paths desgin of complex shape parts.The finite element model of forming conical parts by ISF was built based on software ANSYS/LS-DYNA. The problem of mesh distortion when simulating the forming process of large angle conical parts was solved. The forming paths of 75° conical parts were studyed by numerical simulation as the research method and 1060AI as the blank. The Characteristics of two forming method called "out-to-in’and "in-to-out" were analysed. A four-stages forming path strategy was obtained after improving the forming paths. The wall thickness of the parts formed by the four-stages forming path was well-distributed.Based on the foundation of the desgin of paths, and aim to well-distributed wall thickness, the forming paths of 75°,80°,85° conical parts with different geometric paramenters (opening radiu R, sphere radiu r on the bottom of the cone) were successfully designed. These successsful paths were setted as standard paths. General formulations of the forming paths of 75°,80°,85° conical parts were deduced through geometical relationship. Extract datas from standard paths and use them fitting the key variables in the general fomulations. The parametric ISF paths equations of 75°,80°, 85° conical parts were obtained by substituting the fitting results for the key variables in general formulations.Three parametric ISF paths equations were verified in certain range (30mm≤R≤<100mm) by experiments and numerical simulation. The parametric paths of 80° conical parts were extended to 75°～80° conical parts and 85° extended to 80°～85°. Then the ISF paths equation of a conical part was ascertained with its geometric paramenters in a certain range (75°≤θ≤85°,25mm≤R≤100mm, rmin≤r≤rmax).A UG application program of modeling the parametric ISF paths was developed based on UG/Open Grip. The CAD model of parametric ISF paths can be obtained immediately through the application program when the three geometric parameters θ, R, r were input.