Seismic Analysis of Sagging Elasto-flexible Cable using Placement Model

Weightless sagging elasto-flexible cables lack unique natural state. However, heavy cables are assumed their natural state under their self-weight for predicting their static and dynamic response. In most of the existing literatures the nodal coordinates or placements are generally defined in reference to the chosen Cartesian coordinate system for the discrete formulation called here Placement Model. In this paper, Placement Model is applied to predict the seismic response of weightless sagging cables. The cable is fixed at their both the ends and two masses are attached in its intermediate points leading to a 2-node 4-DOF system. The dynamic response of the cable node is investigated by applying two different seismic excitations in three different conditions as only horizontal excitation, only vertical excitation and both horizontal and vertical excitation act simultaneously. El-Centro and Loma Preta Seismic excitation is applied to predict the seismic response of the cables.