Design of loading trajectory for VTL numerical control stretch forming machine

Based on VTL numerical control stretch forming machine introduced from abroad, 3D digital model was built and mechanism motions were analyzed.For stretch forming process of aircraft skin, a loading trajectory design method was given.Firstly, jaw trajectory was designed using deformation control, which was then translated to driven parameters according to the rules of the stretching machine.And loading trajectory design software was developed on the platform of CATIA using CAA technology.Finally, detailed design processes of loading trajectory for stretch forming of cylindrical skin were provided as an example.The feasibility of the loading trajectory design methods was verified by the FE simulation and experiments carried out.