LARGE DEFORMATION ANALYSIS OF STRUCTURES ENCLOSING AIR CAVITIES

摘要

In this paper, a method to analyze structures that enclose cavities filled with an ideal gas such as air is presented. The method has been implemented in a commercial nonlinear finite element program. The power of this method is in its simplicity and user friendliness. The change of pressure in the cavity resulting from the large deformation of the structure due to the application of external forces is automatically evaluated according to the ideal gas equations. The volume of the cavity is continuously updated and used to determine the changes in the cavity pressure. The method has been extended to model cavities partially filled with incompressible fluids and air. The method has also been successfully used in coupled thermal-stress problems. Several applications that use this method are presented. The applications range from simple problems used to validate the accuracy of the method against other techniques in the literature to real practical applications. Applications presented include fluid containers, airsprings and rubber seals.