Adaptive Time-delay Compensation And Test Platform For Real-time Hybrid Testing

Due to its high efficiency and wide applicability,the real-time substructure testing(RTST)method has received more and more attention in the field of structural testing during the past 20 years.RTST is efficiency and much lower cost than others.However,there is high requirement for the facility for doing RTST.Even the hardware has been improved in recent years,it still has many limitations.For example,it is difficult to meet the requirement of real-time(RT)calculation for nonlinear and complex numerical substructures;and there is an inevitable delay in the loading equipment and control loops,which lead to the inability to apply displacement accurately on time.How to construct a reasonable numerical and physical substructure and eliminate the influence of the time delay is the key issue for a successful RTST.The summary of this dissertation listed below.(1)Firstly,based on the Matlab/Simulink software and the theory of hydraulic servo system,a virtual simulation model of the hydraulic actuator is established.The dynamic characteristics of proposed model is compared with the real actuator.Using square,triangle,sine and band-limited white noise wave as the input,the maximum error for the proposed model is lower than 10%,which proves the proposed model’s accuracy,and provides a foundation for new control algorithm development and real-time substructure testing platform debugging.(2)Secondly,this study proposes an adaptive compensation method for RTST based on time-delay tracking.The compensation effectiveness is proved by the simulation model,MTS hydraulic servo system and Servotest hydraulic servo systems.During the test,TI(time-delay tracking indicator)value is between±20 mm~2.By using an aluminum alloy beam and water as the loading specimen,it is verified that the proposed delay compensation method has good compensation effect when the loading specimen goes into nonlinear,plastic phase and coupled with fluid dynamics effects.The robustness of the delay compensation method is proved.(3)Finally,this study builds a RTST platform based on Opensees/Openfresco.By comparing the results of the simulated substructure testing with the finite element analysis,the error of the two methods is less than 5%,which proves the correctness of the constructed RTST platform.After that,RTST was carried out for further proving the feasibility of the test platform.