Inverse Analysis Of Dynamic Loads Based On Dynamic Response Of Tall Building

Typical environmental dynamic loads such as wind load or earthquake action have an important impact on the safety of building structural design,but in actual engineering,it is very difficult to directly measure the environmental excitation of the structure.Considering the fact that the current measurement technology of the structural dynamic response is relatively mature,and the measurement accuracy of structural acceleration response and displacement response is much higher than that of load,the inverse analysis method to identify structural dynamic load based on the structural dynamic response become a new approach of indirect measurement of dynamic load.Based on the continuous Kalman filter theory,this paper proposes an inversion method for identifying the dynamic loads of tall buildings by partial floor dynamic response.This paper takes the Taipei 101 building in China as the research object,combines the characteristics of wind-induced vibration of tall buildings and modal transformation theory,determines the modals controlling structural vibration according to the proper orthogonal decomposition(POD),and selects the appropriate several layers according to the optimized point layout principle,the research work on wind load inversion of tall buildings based on large eddy numerical simulation wind-induced response data was carried out.The effects of different modal truncation participation,structural parameter error,different noise levels and initial values on wind load inversion identification are analyzed,the results show that the inversion results are consistent with the accurate results,indicating the wind load results by proposed method are stable and reliable,and the robustness is good.At the same time,based on the several layers' s measured data under the typhoon “Matsa”,the wind-induced response of the structural wind load and the unmeasured floor is identified,the results show that the wind-induced response,inversion wind load time history and power spectrum are in good agreement with the true results.The inversion results under different layer input conditions are very close.The accuracy and applicability of the proposed load inversion method for wind load inversion identification of tall buildings are further verified.The research on the numerical simulation of the ground motion of tall buildings under the EL-Centro wave in the Taipei 101 building was carried out.According to the dynamic characteristics of tall buildings,the Proper orthogonal decomposition(POD)method and the optimized point layout principle are used to determine the modals controlling structural vibration and the appropriate measuring point position.The ground motion inversion results are obtained by combining the statistical average method.Using structural ground motion input as an accurate result,the comparison of the two methods verify the applicability and accuracy of the proposed load inversion method.The study also analyzes the influence of modal truncation participation,structural parameter error and noise level on ground motion inversion.The results show that with the increase of modal participation number,the accuracy of inversion results is higher and higher,and the inversion method is not sensitivet to structural parameters error,and the inversion results under the influence of noise still show good "tracking" performance for the true value.In addition,this paper also analyzes the ground motion inversion of the Taipei 101 building based on the measured data of several layers under the “Wenchuan” earthquake.The results show that the proposed dynamic load inversion method can identify the structural ground motion based on the inversion of several layers' s acceleration response data.Ground motion inversion time history and accurate time history are strongly correlated,the inversion spectrum is higher than the accurate spectrum in the low frequency band,but the trend in the main frequency band is basically the same,the degree of coincidence is very high,further verifying the the dynamic load inversion method is also effective and feasible for the ground motion inversion of tall buildings.The above research shows that using the dynamic response data of several layers to invert the wind load or ground motion of tall buildings is an effective method to indirectly obtain the dynamic load of tall buildings.The proposed results in this paper are valuable and referential to wind-resistant and seismic design of tall buildings.