Energy Index Approach for Damage Detection in Nonlinear Highway Structures

摘要

Effective detection of structural damages has been a challenging issue in the health monitoring of highway bridge structures. Most currently used nondestructive detecting techniques, though, rely heavily either on extensive measurements of local structural behavior or on analysis based on linear dynamics using simple structural models. Their applications, therefore, are often limited by the experimental costs and the complexity of real bridge structures. This research explores the possibility of applying an energy index approach in general nonlinear finite element analysis for damage detection in highway bridge structures. The nonlinear behaviors of the bridges under dynamical loading conditions due to material inelastic deformation and crack damages have been considered. It is shown that by utilizing the energy balance rule for a general, dynamically loaded nonlinear solid body a spatially indexed, scalar energy parameter can be formulated based on the generalized J integral used in fracture mechanics. The evaluation of such an energy index can be implemented into general 3-dimensional nonlinear finite element analysis procedures in computer simulations to detect and locate the structural damages within the highway bridge structures. The effectiveness and feasibility of the proposed energy index approach are illustrated in numerical simulation studies.