An integrated structural health monitoring system for engineering structures : a case study using physical method

Abstract

Structural integrity of a structure is the ability of it’s components to hold together under the adverse action of rarely occurring excessive loading and aggressive environment condition. Any civil structure must be able to prevent catastrophic failure by undergoing deformation in a manner predicted during the design phase, thereby avoiding untoward incidents that can claim precious human lives and cause extensive damages. A promising technique to ensure that such catastrophic failures will be prevented is through the implementation of a robust Structural Health Monitoring (SHM) system. An efficient SHM system should be able to measure the structural deformation with minimal noise, analyse the output from the sensors installed, provide effective communication and enable the formulation of appropriate corrective action. One of the inevitable component of the structural health monitoring system is Finite Element model updation. For the past decades, there has been substantial research carried out in the field of Finite Element (FE) updating based on change in the dynamic characteristics of the structure. This paper presents a case study on health monitoring of a test bed chosen in the NITT campus using sensors, a stand-alone data acquisition system and an Internet of Things (IoT) based data transmission platform. The paper provides a method for finite element updation which plays a vital role in the implementation of real - time monitoring system. A 3D FE model of the test bed and a comparative study on influence of frequency residual, mode shape related function, modal flexibility residual and combination of all the three residuals have been done. It is observed that for updating dynamic parameters considering any one of the residual parameter in the objective function is sufficient, however for damage detection and its location, the combination of all the three residuals must be considered in the objective function to get an accurate picture of the damage. There is a brief review on various monitoring techniques practiced in the current scenario which would benefit for further research interest.