Numerical method for simulating skin stretch forming

Aim to study the stretch forming of complex aircraft skin parts, a numerical method for the skin stretch forming of the aircraft skin parts is presented, which is based on the dynamic explicit method and the Belytschko-Wong-Chiang (BWC) shell element. The motion mechanism of the skin stretch machine is analyzed, and node velocity constraint as a method of the boundary treatment for the skin stretch forming is employed by this algorithm. Translation motions in an arbitrary direction and rotational motions around an arbitrary axis can be deal with by this method, which can be applied widely in the simulation of complex aircraft skin stretch forming. The simulation of a practical aircraft skin part is done with the optimal load path of the die and the clamp. The precision and the practicability of this algorithm for aircraft skin stretch forming are validated by the agreement between the simulation result and the experimental result.