The stochastic finite segment in the analysis of the shear-lag effect on box-girders

A stochastic variational principle (SVP) is presented in this paper. Based on the SVP, the stochastic finite segment method (SFSM) is developed for and applied to the analysis of shear-lag effect on a box-girder. The random property of physical and/or geometrical parameters is incorporated consistently into the total potential energy functional of the box-girder. Then the second-order perturbation techniques are employed to develop a set of expanded deterministic expressions of the functional. It is shown that the second-order functional is necessary and sufficient to derive all the governing equations. Then the recursive stiffness equations of the SFSM are obtained by the stationary conditions of the second-order energy functional. The stochastic shear-lag effect on the box-girder is evaluated by means of the SFSM. An example is given to demonstrate the efficiency and accuracy of the present method. Results are compared with the analytical variational solutions and those achieved by the technique of direct Monte Carlo simulation and the finite strip method, respectively, showing desirable agreement.