A framework for quantifying the value of vibration-based structural health monitoring

Abstract

The difficulty in quantifying the benefit of Structural Health Monitoring (SHM) for decision support is one of the bottlenecks to an extensive adoption of SHM on real-world structures. In this paper, we present a framework for such a quantification of the value of vibration-based SHM, which can be flexibly applied to different use cases. These cover SHM-based decisions at different time scales, from near-real time diagnostics to the prognosis of slowly evolving deterioration processes over the lifetime of a structure. The framework includes an advanced model of the SHM system. It employs a Bayesian filter for the tasks of sequential joint deterioration state-parameter estimation and structural reliability updating, using continuously identified modal and intermittent visual inspection data. It also includes a realistic model of the inspection and maintenance decisions throughout the structural life-cycle. On this basis, the Value of SHM is quantified by the difference in expected total life-cycle costs with and without the SHM. We investigate the framework through application on a numerical model of a two-span bridge system, subjected to gradual and shock deterioration, as well as to changing environmental conditions, over its lifetime. The results show that this framework can be used as an a-priori decision support tool to inform the decision on whether or not to install a vibration-based SHM system on a structure, for a wide range of SHM use cases.

Quantifying the Value of Vibration-Based Structural Health Monitoring Considering Environmental Variability

“…The SHM likelihood function is formulated based on the discrepancy between the OMA-identified eigenvalues 𝜆 ̃𝑚 = (2𝜋𝑓 ̃𝑚) 2 and the forward finite element model 𝒢-predicted eigenvalues 𝜆 𝑚 . The likelihood function describing the SHM data obtained at a time instance 𝑡, for an unknown true deterioration state 𝑋(𝑡), is shown in Equation (6).…”

“…Another significant challenge relates to the fact that it is often difficult for owners and operators to grasp the potential benefits of installing SHM systems [4,5]. _____________ The authors are currently developing a framework for the quantification of the Value of SHM (VoSHM) for demonstrating the benefit of continuous vibration-based SHM-aided maintenance planning [6]. The current contribution briefly summarizes this framework, and applies it on a numerical benchmark model of a two-span bridge system subjected to combined gradual and shock deterioration, as well as to environmental variability, over its life-cycle.…”