A Hybrid Algorithm Based on K-L Expansion and Interval Analysis Method for Dynamic Load of Vehicle - Bridge Interaction System with Uncertainty

Abstract

Dynamic load identification of vehicle-bridge interaction system with uncertain parameters is studied in this paper. The vehicle is modeled by a two degrees of freedom mass-spring system and the bridge is modeled as an Euler-Bernoulli beam. A hybrid method that combines the Karhunen-Loève expansion and the interval analysis method is proposed to determine the midpoint value, lower and upper bounds of dynamic load acting on the vehicle-bridge system with uncertainty. The road surface roughness and excitation force of the bridge, which are assumed as Gaussian random processes, are described by the Karhunen–Loève expansion. Uncertain parameters of the structure are considered as interval variables, due to the fact that only their bounds are needed. The moving load identification algorithm can be formulated into an computational inverse problem. To prove the results obtained by proposed method HKIM, the interval analysis method (IAM) is also implemented. The results obtained by proposed method are effective for dynamic load of system with uncertainty.