Pseudodynamic Method for Seismic Testing

The pseudodynamic method is a relatively new experimental technique for evaluating the seismic performance of structural models in a laboratory by means of on-line computer controlled testing. During such a test, the displacement response of a structure to a specified dynamic excitation is numerically computed and quasi-statically imposed on the structure, based on analytically prescribed inertia and viscous damping characteristics for the structure and the experimentally measured structural restoring forces. This paper presents the basic approach of the method, describing the numerical and experimental techniques. Based on current studies, the capabilities and limitations of the method are examined, and possible improvement methods are mentioned. In spite of certain numerical and experimental errors, recent verification tests show that the method can be as reliable and realistic as shaking table testing and that it can be readily implemented in many structural laboratories. The capabilities of the method can be further expanded to test specimens under various load and structural boundary conditions.