Optimization of loading trajectory in skin stretch forming process

The influence of loading trajectory was discussed to solve the precision forming problem of double curve skin in stretch forming. The method of combing finite element analysis and optimization algorithms was proposed to acquire the reasonable loading trajectory. Characteristic and insufficiency of common loading trajectories were analyzed which used in double curve skin forming. Optimization mathematics model was set up in order to reduce springback and improve the fittability. Approximate model and variables range were set up with orthogonal design. The reasonable loading trajectory was found through the numerical simulation and sequential quadratic programming optimization algorithm under the restrictive of maximal thickness strain. The optimization results show that the fittability, strain distributing and thickness uniformity were improved greatly.