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

Quantification of damping in cable systems plays an important role in design of modern cable-supported structures. An attempt is made to estimate the damping for a cable-tie sy~tem, which is essentially a special case of a cable system. A method is proposed based on modal damping ratio, which is represented by the ratio of damping energy to potential energy of cabte system. In order to verify the proposed method of damping estimation, a series of experiments is also conducted with a model of cable-tie system. Two different cable-tie systems are studied to show the applicability of proposed method. Free vibration record is used to estimate damping experimentally. The finite element method is employed to calculate dynamic strain amplitude, which is directly associated with potential energy and dissipated energy. Dissipated energy is assumed to be represented in terms of loss factor and strain energy. The loss factor value of single cable is used to estimate dissipated energy of individual cables in the system. The loss factor of cables are obtained by conducting single cable experiment. Results of experimental and proposed analytical method are cohsistent. It is found that the modal damping ratio of the cable-tie system can be evaluated by considering the contribution from individual cables in the system. Proposed method can be used to estimate damping in a cable system analytically.