Research On High-rise Structure Damage Detection By Statistical Moment

With the development of the economy,the number of high-rise structures in the world is increasing.The high-rise structures involve various fields such as housing,commerce,and office,which are closely related to human beings.In addition,due to the long-term impact of self and external loads,the high-rise structures is vulnerable to encounter varying degrees of damage.Over time,damage accumulates,seriously affecting the safety and reliability of its use.Therefore,it is significant to timely damage detection and safety assessment of the high-rise structure.However,due to the complex of high-rise structure itself,as well as the influence of various uncertain factors,it is still a challenge to find an effective damage detection method.Based on the theory of statistical moment,the eighth moment of acceleration is used as the damage index to identify the damage location of high-rise structure in model-free method.The fusion of the fourth moment of displacement and the eighth moment of acceleration is used as the damage index to identify the damage location and severity of high-rise structure in model-updated method.Based on the probability density evolution theory,the detection of the high-rise structural damage localization and severity with uncertain parameters are carried out.The main contents of this paper are as follows:(1)The statistical moment theory is deduced,considering the sensitivity and stability of each statistical moment,the eighth moment of acceleration is used as the damage index to carry out the model-free structural damage detection.The damage location(s)of the high-rise structure is identified by comparing the rate of change for the statistical moments of each measuring point in the damaged and undamaged state with the corresponding reference value.The numerical simulation analysis of the 21-story frame shear wall structure is carried out using this method,and the effectiveness and feasibility of the method for this kind of structure are verified.(2)An improved model-free damage detection method is proposed.The relationship between the ratio and the floor number is plotted by the eighth moment of acceleration of the adjacent floor structure response,and the damage location of the high-rise structure can be roughly identified.Then the numerical simulation analysis of the 21-story frame shear wall structure is carred out by this method.The validity and feasibility of the method are verified by analyzing the Benchmark model of the super high-rise building structure and the measured data of the high-rise building.(3)The second norm of the first frequency of the structure along with the variation in the fusion index of the fourth moment of displacement and eighth moment of acceleration are taken as the residual norm term,then the first norm of the variation index of the stiffness parameter is taken as the solution norm term.A model modified damage detection method based on statistical moments combined with L1 regularization is proposed.The numerical simulation analysis of the 12-story frame structure and the 21-story frame shear wall structure is carried out respectively,and the optimal range of the regularization parameters is given for each case.The results show that within the optimal regularization parameters,the damage of the high-rise structure can be accurately detected.(4)Considering the uncertainty of the parameters,the probability density evolution theory is applied to detect the structural damage.The equidistant point selection method,the tangent circle and the ball selection method are used to select the representative points.Then the first and second damping ratios of the structure and seismic wave amplitude are regraded as uncertainty parameters.Through the numerical simulation analysis of the 12-story frame and the 21-story frame shear wall structure,this method.is proved to be effectiveness and feasibility.