Random seismic response and sensitivity analysis of uncertain multi-span continuous beams subjected to spatially varying ground motions

13th International Conference on Motion and Vibration Control; 12th International Conference on Recent Advances in Structural Dynamics

Li, Y.Y.^1 ; Zhang, Y.H.^1

State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian

116024, China^1

关键词: Analytical expressions;    Direct differentiation;    Multi-span continuous beams;    Physical parameters;    Random seismic response;    Spatially varying ground motion;    Stationary random process;    Structural parameter;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/744/1/012199/pdf
DOI  :  10.1088/1742-6596/744/1/012199

来源: IOP

【 摘 要 】

An analytical method is formulated for the seismic analysis of multi-span continuous beams with random structural parameters subjected to spatially varying ground motions. An earthquake-induced ground motion is modelled as a stationary random process defined by power spectral density function, and the spatial variation is considered. The physical parameters of the multi-span beams are random and modelled as continuous random Gaussian variables. The stationary random responses are determined as approximate explicit functions of the structural parameters. Direct differentiation of these functions with respect to the structural parameters provides analytical expressions of the sensitivities of the stationary responses. On the basis of Taylor expansion, the statistic moments of the random responses are obtained. Taking the four-span beam as an illustrative example, the mean value and standard deviation of the random responses are computed and compared with those from Monte Carlo simulation to demonstrate the accuracy of the proposed method. Results are illustrated for the influence of different structural parameters on the statistic moments of the random responses. It is found that randomness in Young's modulus and the mass per unit length has approximate equivalent and significant influence on the random responses, while that of damping is negligible.