EFFECTS OF INITIAL TENSION ON DYNAMIC CHARACTERISTICS OF STAY CABLES

Based on a large amplitude cable vibration problem induced by oscillations of a deck, the in-plane nonlinear governing equations of cables under the parametric and forced exciting are derived, in which the static sag and the geometric nonlinearity of the cable are considered and the simple connection condition and boundary condition of the cables and deck are taken into account. Furthermore, the multi-scale perturbation method is applied to analyzing the parametric and forced resonances of stay cables. Then, the effects of initial tension on dynamic characteristics of a longest span cable in a cable stayed bridge are investigated. It is reached as a conclusion that the augment of cable tension will make the softening behaviors of the cable change into hardening behaviors, and that the ratio of pumping frequency to natural frequency will increase from less than 2 into more than 2.