Simulation of closed thin-walled structures partially filled with fluid

For closed structures, the enclosed gas volume can contribute signi®cantly to the strength and sti€ness of a structure. The present paper describes the use of a gas element which is incorporated into ®nite elements for shells. In addition, a method to solve the governing set of equations eciently is described. The method has been applied to a typical packaging example, namely a closed ®lled bottle. To validate the proposed method, numerical studies have been compared with experiments