Identification of Damage in Structural Systems Using Modal Data

摘要

The objective of this research is to develop an efficient damage detection andassessment algorithm for structural systems spatially sparse and noise-polluted modal response. We characterize a structural system by a parameterized finite-element model and we estimate that values of the system parameters using a least-squares minimization of the modal displacement residual. We infer damage from changes in the constitutive properties of elements in the finite element model of the structure. Based on the adaptive parameter-grouping scheme of Shin and Hjelmstad (1994), we propose a new parameter group-updating scheme that has enhanced capability of localizing multiple damage with sparse measurements. The proposed algorithm takes into account the solution multiplicity of the parameter estimation problem arising from using sparse and noisy data. We demonstrate the use of the damage detection and assessment algorithm on two example structures: a planar bridge truss and a three-dimensional tower truss. Numerical simulation studies are employed to examine the capabilities of the algorithm in detecting and assessing damage. The numerical simulation procedure is selected over the real case study because our objective is to quantify the performance of the algorithm rather than to plainly illustrate its use.