Evaluation of integration techniques used in PsD testing methodology

Pseudo dynamic testing (PsD) methodology is used to simulate earthquake effects on the structures or structural components and it consists of both the analytical and experimental parts with a coupled interaction. The dynamic equilibrium equation is generated and the displacement vector to be applied to the specimen in the next step is calculated by using an appropriate numerical integration technique. The overall success of pseudo dynamic tests not only depends purely on the resolution of the measurement devices but also highly depends on the sensitivity and convergence of the integration techniques used for the solution of the dynamic equation of motion. In this study, the success of the central difference method, operating splitting method (OSM) and αoperating splitting methods (αOSM) are evaluated by means of several PsD simulations performed on a steel single degree of freedom (SDOF) system having three alternative constitutive models. The main parameters are the integration technique, time intervals and constitutive models. The advantages of the techniques are compared in terms of the test duration and convergence capability. In conclusion, for all behavior types CDM and OSM methods can be used with the time interval which is equal or larger than the input earthquake data. This means great saving of time during the PsD test and it increase the overall success of the experiment.