Linear model of a pseudo-dynamic testing system

A linear analytical N-DoF model of a complete pseudo-dynamic testing system is developed and calibrated by means of comparison with experimental results. The model is formulated as a state space equation system by assembling the respective equations for the hydraulic actuators, control law, specimen and testing method. For the case of a 1-DoF steel frame specimen, the control characteristics are experimentally obtained and used for the tuning of the parameters of the model. This model can be useful for understanding and quantitatively predicting distortions of the pseudo-dynamic response due to the presence of control errors as well as for simulating alternative testing methods.