NONLINEAR RESTORING FORCE AND DYNAMIC LOADING IDENTIFICATION APPROACHES FOR CHAIN-LIKE MDOF STRUCTURES BY POWER SERIES POLYNOMIAL MODEL
One of the present barriers to the successful realization of structural health monitoring is the lack of efficient and general structural nonlinearity identification methodologies. Moreover, a priori knowledge of the nature and mathematical form of the nonlinearities of typical engineering structures are usually unknown. In this paper, based on the instantaneous values of the state vectors of structures, a power series polynomial model (PSPM) was utilized to represent the nonlinear restoring force (NRF) of the system and to identify the external dynamic loadings, which were applied to part of the DOFs and assumed to be unknown, named partially unknown excitations. The proposed iterative approach, referred to as weighted adaptive iterative least -squares estimation with incomplete measured excitations (WAILSE-IME) , was proposed to identify each coefficient of the polynomial as well as the unknown loadings simultaneously. As a practical consideration, the excitation and response measurements were both contaminated by noise in all cases. The feasibility and robustness of the PSPM under various cases was verified by numerically with a 3-DOF model incorporating a magneto-rheological (MR) damper which is used for simulating nonlinear performance and experimentally by a 4-story frame structure equipped with two MR dampers under impact loadings. The results show that the proposed identification approach for both structural nonlinearity and excitations is capable of effectively representing and identifying the NRF of the nonlinear system studied, and provide a promising way for damage detection in the presence of structural nonlinearities.
Bin Xu Jia He
College of Civil Engineering,Hunan University,Changsha,410082,Hunan,P.R.China Ministry of Education College of Civil Engineering,Hunan University,Changsha,410082,Hunan,P.R.China
国际会议
厦门
英文
226-237
2011-10-28（万方平台首次上网日期，不代表论文的发表时间）