Treatment of discontinuity of frictional force in SI

The numerical estimation of seismic isolation (SI) system with frictional bearing implies an exact solution of pertinent equations of motion. Rigid-perfectly plastic model is widely used technique to approximate the relationship of frictional force-displacement. This paper presents a direct treatment of equations of motion with prediction scheme for discontinuity of slip. The degree-of-freedom of the equations of motion changes with sliding of frictional bearings. A bridge model is used to estimate the numerical results and the results showed good agreement with experimental data.