Dynamic analysis of stochastic prestressed cables

This paper deals with finite element dynamic analysis of cable structures with uncertain pretension subjected to deterministic excitation. The theoretical model addressed is the two-dimensional finite strain beam-theory [1], which allows to eliminate any restriction on the magnitude of displacements and rotations. The dynamic problem is formulated by referring the motion to the inertial frame [2] which leads to a simple uncoupled quadratic form for kinetic energy. The so-called improved perturbation approach [3-4] is employed to solve the stochastic problem, obtaining two coupled systems of nonlinear deterministic ordinary differential equations, governing the mean value and deviation of response. In order to solve this set of equations an efficient and accurate iterative procedure is proposed. A numerical application is presented and results are discussed in order to investigate the influence of random pretension on structural response.