Development of an automotive joint model using an analytically based formulation

A FE model of an automotive structure consists of beam and shell elements. Generally, the pillars and rockers are modelled as beam elements and other parts as shell elements. Beam elements are used since they are more efficie nt than shell elements. A joint is defined as an intersection region of bea m elements, and is generally modelled as coupled rotational springs. In thi s study, a joint modelling methodology is presented. First, the definition and assumptions of the joint are discussed. Second, the joint stiffness ana lytical model is proposed using static load test results. The proposed meth od is more efficient and accurate than existing evaluation methods. Third, the sensitivity analysis method (Nelson's method) and a joint stiffness upd ating algorithm are presented. To verify these methods, the FE analysis res ults of a half size structural model of an automobile with rigid joints and rotational spring joints are compared with experimental modal analysis res ults. (C) 1999 Academic Press.