<title>Damage detection via parameter correction using measured static flexibility matrices</title>

Abstract

Numerical simulation results are presented for a novel damage detection algorithm for detecting damage in smart structures. The method finds damage using a dynamically measured static flexibility matrix. Damage is found through a parametric correction of a large order static finite element model using a much smaller order measurement set. This is accomplished without any model reduction or eigenvector expansion step. The parametric correction is formulated to minimize a residual which is formed using the pseudoinverse relationship between structural flexibility and stiffness matrices. By posing the update problem in terms of measured flexibility matrices instead of experimentally determined modal data, the problems of modal correspondence, mode selection, and modal truncation are avoided. In this paper, numerical simulation results demonstrate that the technique is capable of locating and quantifying damage manifested as a change in local stiffness in the full order finite element model using a measured flexibility matrix obtained for a much smaller measurement degree- of-freedom set. This is accomplished using a non-iterative linear solution and is possible even when the damage is contained entirely in an element not touching the measurement degree-of- freedom set.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.