Energy Dissipation Based Structural Condition Assessment Using Random Decrement Technique

Abstract

AbstractThis study investigates the potential application of the random decrement (RD) technique for condition assessment in beam-like structure based on energy dissipation of material, when only acceleration responses are available for use. First, an analytical model of viscoelastic beam with various levels of energy dissipation was used, based on modal superposition principle, to obtain the response of systems to input force. Then, RD technique is employed to calculate to transform the random structural response into the free decay response. RD technique is only based output measurements, whereas other traditional methods need requirement of both input and output ones. In structural engineering, input ambient excitations (wind, earthquake and traffic load, etc.) are difficult to determine. Finally, a new feature established from the Power Spectral Density (PSD) of Randec signature, call the Displacement Loss Factor function (DLF), is used to assess structural condition. Numerical simulations of a linear beam loaded by white noise are used to verify the effectiveness of the method in assessing the structural condition.KeywordsEnergy dissipationRandom decrementPower Spectral Density