Method And Verification For Bi-directional Hybrid Testing

Hybrid testing,as an important structural seismic test method,can provide the response of structures during a certain earthquake.Research shows that the action of an earthquake onto structures is often bi-directional instead of unidirectional and bi-directional earthquake makes more damage to structures.Therefore,it makes sense to perform an accurate bi-directional hybrid testing.Based on the studies about the method and verification for bi-directional hybrid testing before,the specific work of this paper is as bellows.First,in consideration of the nodus in the bi-directional hybrid testing,the transformation equation of coordinates is established to explain the position relationship between the displacement of structure and reading of transducers.Based on this,the paper proposes a new updating method for actuators displacement command which is based on Newton iterative method and a new redundant control method based on capacity of actuators in which the redundant actuators use force command,which forms the force-displacement control method of hybrid testing.Second,use Simulink to establish the model of actuators and simulate the whole procedure of hybrid testing to compare four different control methods.The result shows that the updating method based on Newton iterative for actuators displacement command works well.For linear elastic structures,all the redundant control methods have good performance.But when referring to nonlinear structures,force-controlled redundant method works obviously better than the others.Third,integrate the control method mentioned in this paper into the Hy Test and conduct a single-storey steel frame bi-directional hybrid test.The result of test demonstrates that all control methods works well in displacement following and force distribution optimization,which proves that the control theory in this paper is correct.Force-controlled redundant method has a better performance because of its convenience.