ISSUES IN STRUCTURAL INVESTIGATIONS: VIBRATION BASED APPROACH VS. ELASTIC WAVE PROPAGATION APPROACH

Sanjay Sengupta, Aloke Kumar Datta , Pijush Topdar

Abstract: Structural investigations are often related to identification of damages in structures. For survival of the structures through their design lives with full capacity, structural health monitoring (SHM) techniques are used for identification and remedy of damages. SHM is generally carried out in three steps viz periodic visual inspection followed by non destructive testing and sensor based continuous monitoring. The sensor based continuous monitoring, as suggested by the available literature, is based mainly on two different approaches such as vibration based and wave propagation based. One of the potential wave propagation based approaches for SHM is Acoustic Emission (AE) technique through which the location of the damages can be predicted in real time. On the contrary, vibration based approach may be effectively used for damage quantification as it considers the structural properties e.g. stiffness, damping etc. unlike wave propagation based approach. In this study, the commonly used forcing functions for numerical simulation of the AE source, as used in the wave propagation based approach, has been considered to create an internal excitation in the structure causing vibration of the structure. The displacement responses are studied for thin plate using finite element method and compared with the available response data from elastic wave propagation technique. The results are found to follow similar pattern.

Keywords: Structural health monitoring, Identification of damages, Acoustic Emission (AE) technique, Finite Element Method, Displacement Response

DOI: https://doi.org/10.15623/ijret.2015.0425041