Research On Damping Identifying Of Shake Table Test For Wood-Concrete Hybrid Structure

Modal analysis and parameters identifying is an analysis method which is called athwart question in structure dynamics. So far, The method that associates experiments with theoretic analysis to handle up the vibration problem is extensively applied in each engineering realm and it is becoming important means to solve structures' vibration problems. The goal of Modal analysis is to identify modal parameters for analyzing system of structures' vibration characteristic,fault diagnosis,forecast and providing gist to optimum designing.This text mainly inquiry into the problem of damping analysis. The damping is much difficult in modal analysis because its complexity. So far, a kind of Self-contained and valid damping model to reflect tangibly actual structure of damping characteristic is not built up and a series of problems caused by damping for structure of designing and optimum are greatest important. there are many methods for identifying model analysis, but each method has respectively different merit and shortcoming under the concrete condition. As North America light wood frame structure going into Chinese market more and more, more exact method of damping identifying is needed to be found for further dynamic analysis of structure in order to studying seismic performance of light wood frame structure.The following works is to be done in this thesis:1. Deduce theoretic model of transfer function for shaking table test.2. Obtain various measuring points' frequency response function through the Fourier transformation based on measuring points' acceleration time history data tested by shake table. Take the theoretical model of frequency response function as the foundation, elaborate separately the basic philosophy of misalignment weighting least squares method,the rational fraction polynomial method which are used for this model parameters identifying, and establish related procedure.3. Obtain the structure free damping curve through the stochastic decrement method based on structure ridge absolute displacement time history data tested by shake table, establish the ARMA time series method procedure which is used to identify the structure damping.4. Take the actual data of shake table test for wood-concretes hybrid structure as a foundation, utilize the above three method to identify structure damping, and compare with the half-power bandwidth method, point out different merit and shortcoming for each method, obtain the structure damping value scope under the condition of different rigidity,quality and acceleration peak value.5. According to the damping value which is obtained by above idengtifying methods, propose the suggested damping value when designing the wood construction, and put forward proposal to future experiment and the damping identifying methods.