Accuracy and stability of the substructure algorithm with sub-step control

In this doctoral research, investigation on substructure algorithm and development of error compensation algorithms are carried out. The investigation is focused on analyzing the accuracy and stability of the substructure algorithm with sub-step control and the development is aimed at proposing new error compensations for improving accuracy and stability of real-time substructure tests. There are three major achievements in this research. Firstly, the results of accuracy and stability analyses are helpful in understanding accuracy and stability of the substructure algorithm and useful in selecting appropriate parameters for real-time substructure testing. Secondly, new force compensation is developed for compensating error force in the substructure algorithm. Thirdly, new phase lag compensation is developed for the control of hydraulic actuators. Based on on-line system identification, both error compensations have some advantages such as having adaptive capability and no requirement of a pretest for system identification.