Since the cable is one of primary structural elements in a cable stayed-bridge,the tension force of a cable in the bridge is very important parameter to be measured during construction and even in-service for assessing the safety and integrity of the cable bridges.Inpractice,vibration based method is commonly used to estimate the cable tension force in cable-stayed bridges due to its simplicity in test procedures.However,although the vibration based method is very practical and cost effective,it has some limitations in accurate measurements of the cable tension force in real bridges.One such problem is the uncertainties of essential parameters such as length and mass of the cable in real bridges.Uncertainties of those parameters often lead to an erroneous result in the estimation of the cable tension force in field.For this reason,many research efforts have been devoted to develop nondestructive methods for cable tension force measurements as an alternative to the vibration based method.