Modal Parameters Identification And Vibration Evaluation Of Timber Structure

Chinese timber structure have high historical significance and artistic value,But many buildings have been built long years ago,so there are already a large number of damaged phenomenon in the internal structure.At present,the recently study is mainly focused on the architectural style,decorative arts and static performance,at the same time,the study about the dynamic performance is few.The object of this paper is timber structure such as Potala Palace and the Forbidden City.The modal parameters are obtain based on the filed test,and the vibration assessment is proceed based on the long-term monitoring.The main contents include the following aspects:Firstly,based on the characteristics of the timber structure a modal parameter identification method is proceed which is suitable for timber structure.And the numerical model is established to comparison with the two method.Then,based on the field measurement data,use the new method which is proceed before to obtain the modal parameter and evaluate the goodness of fit.Finally,on the basis of obtaining the dynamic parameters of the structure,the vibration of the structure under normal working condition is evaluated and analyzed.A long term monitoring of human-induced vibration has been took into the floor of Potala Palace.In order to analyze the large number of data,a signal removal method based on RMS is proposed to remove structural vibration not caused by tourists quickly.And the method is discussed and evaluated from three aspects:theoretical analysis,numerical simulation and field test.Then,the long-term monitoring data are filtered and the artificial vibration is evaluated.