A deflection-based practicable method for health monitoring of in-service bridges

Abstract

This paper presents a static deflection-based method for structural health monitoring of in-service bridges. In the past, the use of static as well as dynamic measurements has been investigated for damage detection in bridge elements. However, most of these methods are complex and work only in laboratory settings. Moreover, implementing such methods for in-service bridges is a challenging task. The method presented in this paper is based on a simple structural analysis principle and can be implemented for in-service bridges. Using the principle of virtual work, an analytical expression for deflection change (DC) (i.e. the difference in deflection for healthy and damaged beams) and a consistency function are derived. A plot of the DC curve reveals the damage location, and the consistency function is used to assess the damage severity. Numerical case studies and laboratory experiments are presented to investigate the effectiveness of the proposed method in different cases, such as a simply supported beam subjected to uniform loading and a cantilever beam subjected to uniform loading. Satisfactory damage localization and quantification results were achieved even with a small number of sensors. Both numerical and experimental analysis results show that the proposed model performs reasonably well at detecting and assessing the damage in bridge elements.