Experimental Methods in Earthquake Engineering - Dynamic Behavior of Concrete and Seismic Engineering - page 167

5.1. The pseudo-dynamic method
5.1.1 . Introduction
Even if performed in a quasi-static way, the pseudo-dynamic test (PSD) on the
one hand combines on-line calculations and control and on the other hand the
continuous measurement of the properties of a given structure, allowing researchers
to simulate the dynamic response of a structure in a realistic way.
The motion equations of a discrete system modeling the structure during the test
are integrated by a step by step numerical algorithm. The viscous damping and
inertia forces are modeled analytically, which is simple when compared to the task
of modeling the non-linear forces that develop in the structure, and are measured
experimentally. In most cases, it is impossible to model them accurately. This
process allows both the hysteresis damping linked to irreversible strains and the
damage of structural materials (typically the main dissipation source during an
earthquake) to be taken into account.
Figure 5.1. Pseudo-dynamic method
Let us consider the building in Figure 5.1. To simulate its response to an
earthquake, a recording of the acceleration of an earthquake (either natural or
artificial) is supplied as input to the computer in charge of the PSD method. The
horizontal displacement of the building floors (where the mass is supposed to be