Monitoring Damping in Pseudo-Dynamic Tests

By comparison of dynamic and pseudo-dynamic tests, it is shown that conventional construction materials exhibit pure hysteretic damping and consequently, when quasistatic restoring forces are measured directly, the addition of viscous damping in the equation of motion must be avoided unless it is intended to reflect missing physical elements. Equally important in pseudo-dynamic testing is the fact that the apparent damping can be easily distorted by the inevitable control errors. The identification of a spatial model from the results of the tests allows obtaining a reliable estimation of the damping distortion for each vibration mode.