Damage detection in bridges using accurate modal parameters

Damage identification in civil engineering structures using the dynamic system parameters has become an important area of research. A reliable, time and cost effective method is therefore required to evaluate and localize damage using the changes in dynamic parameters between the intact and damage states. The dynamic parameters must be calculated in as accurate manner as possible. In the present work, eigenvalue analysis is carried out using Lanczos algorithm in an adaptive h-version finite element environment in order to control the discretization error for accurate evaluation of modal parameters. Standard Ahmed Shell elements have been used for the discretization of bridge deck. Changes of natural frequencies between the damaged and intact model have been observed. A better localization of damage could be done by considering curvature of the mode shapes, which shows more sensitivity than the mode shapes themselves. Numerical studies are conducted to demonstrate the necessity of adaptive eigenfrequency analysis by considering simply supported and continuous bridges containing damaged parts at different locations and their usefulness in the application for damage detection in the field. (C) 2002 Elsevier B.V. All rights reserved.