Understanding mean-axis conditions as floating reference frames

Abstract

The use of the so-called mean axis conditions as a floating reference frame for moving deformable bodies is discussed. This reference frame is compared against the commonly used nodal-fixed frame. The discussion on various issues associated with these frames is facilitated through simple schematic visualizations. The equations of motion for a moving deformable body are analyzed in both nodal and modal spaces. Issues associated with the extraction of the free-free and constrained modes are also discussed. It is shown that the mean-axis conditions can be employed effectively to represent a floating reference frame for a moving deformable body.