In recent years, significant advances have been made in analysis and testing of vehicle frames. In particular, sophisticated finite element techniques have been developed that enable the designer to predict and evaluate frame design from the drawing board stage. However, most applications of this technology have, until very recently, been aimed at evaluating static response of the frame to certain “program” loads. This paper describes applications of an approach that considers interaction between the frame and remaining vehicle components (suspension-power train-body structure) during dynamic loading of the entire vehicle.
Techniques and applications of dynamic frame modeling are presented, including discussions of open section beam modeling, cutouts, joint flexibilities, and attachment considerations. Methods for determining dynamic properties of remaining vehicle components, including concepts of digital Fourier analysis and constrained modal testing, are described and illustrated by means of actual applications. Concepts for assembling and solving the total vehicle governing equations are presented for static, periodic, transient, and random in-service loadings.