Interaction Between Test Structure and Shake Table Powered By Servo-hydraulic Actuation

Abstract

This study focused on the interaction between shake tables and test structures. The shake tables are usually powered by servo-hydraulic actuation and under displacement control. The dynamic response of test structures may lower the ability of the shake table to produce motion at the natural frequency of the test structures. Models of the shake table at the Earthquake Engineering Research Center (EERC) and the new table at the Ningbo University of Technology (NBUT) were created in this study. Parametric analyses revealed that the table-structure interaction is affected by the dynamic response speed of the shake tables in addition to other known factors such as structural properties and table control parameters. The adverse impact of table-structure interaction increases with an increase in the mass of test structure and a decrease in its damping. When the natural frequency of the test structure is within the working frequency bandwidth of the shake table, the table may still be able to generate ground motion that can cause large responses in the test structure; however, when the structures’ natural frequency is outside the bandwidth, the test structure may not be able to develop sufficient responses to the simulated earthquakes.