Abstract:

In this paper the boundary integral equation for torsio-nal free vibration problem of revolution bodies is derived. The boundary integral term in the equation is discretized with linear interpolation boundary elements and the domain integral term with 8 nodeSerendipity finite elements. The equation is condensed by taking thefinite element nodes as master degrees of freedom and a generalized eigenvalue problem with a few degrees of freedom is established. Typical examples are studied. The numerical results show that higher accuracy could be obtained and fewer degrees of freedom are needed by using Serendipity elements than constant value elements. Results are remarkably improved as meshes refined. Computations are reduced due to condensation.

Key words: boundary element method, free vibration, revolution bodies condensation