Moving force identification based on stochastic finite element model

Abstract

A moving force identification technique based on a statistical system model is developed in this paper. Karhunen-Loéve expansion is employed to represent both the random forces and system parameters which are assumed to be Gaussian distributed with the bridge-vehicle system as the background of study. Road surface roughness is a main contributor to the randomness in the moving force. A statistical relationship between the random moving force and the random structural responses is established basing on which a general stochastic force identification algorithm is formulated. Numerical simulations are given to verify the proposed algorithm and to quantify the error which arises at different stages of the identification. Case studies including the effect of number of samples and the level of randomness are conducted to check on the robustness of the proposed algorithm. Results show that the assumptions made in the identification are appropriate and the proposed Stochastic Force Identification algorithm is effective.