A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology

Thesis (M.Eng.) - Asian Institute of Technology, 1992

In the present study, the modal damping of structural cables is conceived to be increased by using a damping treatment. An attempt is made to analytically estimate the modal damping of a composite Parallel-Wire-Strand Cable which is to be made by introducing some viscoelastic material between strands and· the outer cover pipe. The effect of such damping treatment on modal damping is discussed in terms of energies and energy loss factors in axial and bending modes of deformation. The energy loss factor in axial deformation and the energy loss factor in bending deformation are analytically estimated. The energy in cable under flexural vibration are calculated by finite element method. It is found that the modal damping of cable can be in creased by increasing the axial loss factor by using viscoelastic material with higher loss factor and higher modulus of elasticity. The contribution of bending loss factor to the total modal damping of composite cable is not much because of less deformational energy in bending in case of long cables.