Force-displacement hybrid control of experiments on engineering structures with multi-degree-of-freedoms
Engineering structures sustain the spatial loads from gravity,winds,earthquakes and so on.To examine the mechanical performance of such structural members,the forces in all six degrees of freedom(DOF)need to be imposed synchronously.Because of the rigidity of a specimen,there are strong coupling effects among the six DOFs,which bring significant difficulty in the control of traditional linear actuators.To solve this problem,the force-displacement hybrid control strategy with dual loops is proposed in this study,where both material and geometric nonlinearities are well considered.The mutual transformation between the displacement and the corresponding force is realized by the stiffness-based iterative procedure.This iteration has been well incorporated into the closed loop control scheme to avoid the loading path effect for nonlinear specimens.The convergence of proposed scheme has been proved theoretically.And the controller is designed to achieved the uniform convergence of the closed-loop control system for a nonlinear function solving process.Based on a Stewart platform,the hybrid control program was developed to fully control the six DOFs on a specimen boundary.The accuracy and stability of the proposed scheme was first validated by a cyclic quasi-static loading of a metallic column specimen.It has been observed an accurate and stable control of the specimen has been achieved although there exists strong coupling between various DOFs at the boundary.
MDOF system Force-displacement hybrid control Decoupled control Dual loop control Online hybrid test
H.Zhou S.Zhu M.Li T.Wang
Associate Researcher,Key Laboratory of Earthquake Engineering and Engineering Vibration,Institute of Master candidate,Laboratory of Earthquake Engineering and Engineering Vibration,Institute of Enginee Researcher,Key Laboratory of Earthquake Engineering and Engineering Vibration,Institute of Engineeri
国际会议
The 7th World Conference on Structural Control and Monitoring(7WCSCM)(第七届结构控制与监测世界大会)
青岛
英文
1273-1284
2018-07-22（万方平台首次上网日期，不代表论文的发表时间）