리바요소를 이용한 공기 스프링의 특성 해석

Abstract

Recently, the air suspension replaces conventional steel springs since it provides a smooth ride quality and self–leveling. Air–spring is a main component in the air–suspension system. Automotive industries require accurate simulation method for an air–spring in order to reduce time and effort in a design stage. It is most important to develop an efficient finite element model for the air–bellows in an air–spring since the inflated shape of the air–bellows directly effects on the characteristics of an air–spring. Adequate method which could characterize the high anisotropic behavior is required in order to analyze the air–bellows. The air-bellows is composed of a fiber reinforced rubber composite, and high anisotropic behavior is induced by or several layers of embedded fiber cords. This paper formulates a 4–node membrane based rebar element that considers change in fiber orientation during deformation of the composite. A finite element program was constructed based on the updated Lagrangian formulation considering both geometric and material nonlinearity. Contact scheme, which was based on penalty method, was contained in the program to consider effects in interference of the air–bellows with other components of the air–spring. Finite element analyses of an air–spring were carried out and spring coefficient of the air–spring was obtained.