Breaking Wire Detection and Strain Distribution of Seven-Wire Steel Cables with Acoustic Emission and Optical Fiber Sensors.

摘要

Cable-stayed bridges have been increasingly used as river-crossing links in highway and railway transportation networks. In the event of an abnormal situation, they can not only impact the local and national economy but also threaten the safety of passengers. To assess the structural condition of cables, the strain distribution among multiple wires must be effectively determined as one or more wires are broken due to overstress and/or corrosion. This proposal is focused on a preliminary study of wire breakage detection and associated strain redistribution. The specific objectives are to develop and validate a new algorithm for the localization of broken wires with acoustic emission technology and a new model for the determination of strain redistribution with distributed optical fiber sensor measurements. Both laboratory tests and numerical simulations will be conducted to understand the mechanism of strain redistribution as a result of wire breakage. In particular, a seven-wire steel cable will be tested and analyzed to take into account both the initial stress due to wire twisting and the friction effect between wires. For sensitivity study, various section losses in percentage of sectional area will be considered to understand the effective length of a cable over which the strain condition prior to the loss of wire sections can be recovered.