FAULT IDENTIFICATION OF BEAMS ON ELASTIC-FOUNDATION

The capability of identifying both location and severity of damages of faulted elements in a structural system is greatly needed under the p resent demands of constantly maintaining the safety of civil engineeri ng structures. Presented in this paper is a methodology based on vibra tion theory that can be used for the detection of faults in a beam of either uniform or nonuniform cross section and under a variety of boun dary conditions, including simple support, cantilever support, and bea m on elastic foundation. Theoretical developments of the methodology a re presented first, followed by numerical experiments to demonstrate t he feasibility of the method. Numerical experiments include various da mage scenarios such as those faults occurring in a beam section as wel l as in a subgrade foundation. Furthermore, damage scenarios involving both single fault and multiple faults are also presented. The defect of the supporting subgrade foundation can be modeled either as degradi ng subgrade stiffness or increasing damping values. Numerical experime nts demonstrate the feasibility of the developed NDT methodology which warrants the next stage of field study.