The Pseudo Dynamic (PSD) test has many important advantages over the shaking table test, that is believed to be the most accurate way to get the earthquake response of a structure, but it also has many disadvantages. One big disadvantage of the PSD test is the difficulty in controlling the test, special care has to be taken in order to control the load actuators during the test. According to Kusunoki, et al 2002: It is often reported that dynamic responses of testing structures are much affected by cumulative control errors. Some of these errors cannot be eliminated due to limitations in control system.
Therefore in every PSD test performed there is always an error on the response of the structure. It is important to understand and estimate the error that can be produced during a PSD test, because estimating this error can let the researchers make adjustments to their models or to the PSD test set up before performing the PSD test or have a better understanding of the results from a PSD test.
The objectives of this study are: 1) Estimate and analyze the effect of the Displacement Control Error on the frequency content of an earthquake response obtained using PSD test. 2) Estimate and analyze the effect of the Displacement Control Error on the Force vrs. Displacement curve of a structure tested under PSD test. 3) Estimate and analyze the effect of the displacement control error on the maximum displacement of the response. 4) Analyze the characteristics of the undershoot and the overshoot error.
The procedure to achieve the objectives of this study is: First, an appropriate tool, which was developed by Koichi Kusunoki, for estimating the effect of the Displacement Control Error was chosen. Second, two earthquake records were chosen based on their frequency content. Third, a linear model and a bi-linear model were decided for the study. Fourth, seven different structural models were chosen for this study. Fifth, an adequate integration method was chosen. Sixth, The PGA’s of the earthquake records were modified in order to impose the desired displacements in the structure models. Seventh, the simulations were performed. Eighth, Analysis of the results was performed. Ninth, conclusions for this study were obtained.