DAMAGE DETECTION IN CONTINUES BRIDGE DECK AND ASCE BENCHMARK VIA INSTANTANEOUS ENERGY METHOD

One of the main concerns for structures and infrastructures is their inspection via the Structural Health Monitoring (SHM) approaches to ensure their functionality and/or performance. Structures are exposed to natural hazards and manmade accidents in their lifetime, which may cause serious damages. In order to detect theses defects SHM is an efficient tool to ensure structural safety and protection (Pierdicca, 2016). One of the major challenges of current engineering knowledge is to obtain low-cost SHM especially after the occurrence of an accident (Xu & Xia, 2011). SHM aims to detect real characteristics of a system and detecting its possible damage. This may be due to changes in geometric characteristics, material modifications, or reductions in cross-sections and so on. Among various SHM approaches, health monitoring of infrastructures (ISHM), especially bridges has been presented more challenges for engineers. In modern societies, ISHM as an efficient tool can play a significant role in the maintenance and safety of bridges. Its main purpose is to be a part of the structural maintenance schedule to evaluate their real performance against unexpected environmental disasters (Wong, 2004; Abe & Fujino, 2009). This paper attempts to propose a new damage detection procedure for continuous deck bridges and also the threedimensional framework of the ASCE benchmark structure. First, by utilizing HHT, the instantaneous amplitude and frequencies of the measured acceleration responses are extracted for both healthy and damaged cases. Then, by introducing the instantaneous amplitude energy damage index (EDA) and the instantaneous frequency energy (EDI), the location of damages are detected. To assess the feasibility and reliability of the proposed methods, several analytical models of concrete bridges of one and two-spans, and the ASCE benchmark problem have been used. To consider the robustness of the proposed method, contamination of signals during the data acquisition process is investigated. The results in the analytical and experimental models showed that the proposed methods can determine the damage locations with appropriate accuracy for different damage scenarios and it may provide reasonable results for rapid estimation.

کلیدواژه ها:

Damage detection ، Structural health monitoring ، Instantaneous responses ، Energy index ، ASCE benchmark