Abstract

The benefit of Structural Health Monitoring (SHM) can be properly quantified using the concept of Value of Information (VoI), which is, applied to an SHM case, the difference between the utilities of operating the structure with and without the monitoring system. The aim of this contribution is to demonstrate that, in a decision-making process where two different individuals are involved in the decision chain, i.e. the owner and the manager of the structure, the VoI can be negative. Indeed, even if the two decision makers are both rational and exposed to the same background information, their optimal actions can diverge after the installation of the monitoring system due to their different appetite for risk: this scenario could generate a negative VoI, which corresponds exactly to the amount of money the owner is willing to pay to prevent the manager using the monitoring system. In this paper, starting from a literature review about how to quantify the VoI, a mathematical formulation is proposed which allows one to assess when and under which specific conditions, e.g. appropriate combination of prior information and utility functions, the VoI becomes negative. Moreover, to illustrate how this framework works, a hypothetical VoI is evaluated for the Streicker Bridge, a pedestrian bridge on the Princeton University campus equipped with a fiber optic sensing system: the results show how the predominant factor that determines a negative VoI is the different risk appetite of the two decision makers, owner and manager.

摘要

结构健康监测 (SHM) 的好处可以使用信息价值 ( VoI ) 的概念进行适当量化，即应用于 SHM 案例，在有和没有监控系统的情况下运行结构的效用之间的差异。这篇文章的目的是证明，在决策链中涉及两个不同的个人（即结构的所有者和管理者）的决策过程中，VoI可能是负面的。事实上，即使这两个决策者都是理性的并且暴露于相同的背景信息，由于他们对风险的不同偏好，他们的最佳行动在安装监控系统后可能会出现分歧：这种情况可能会产生负面的VoI，这正好对应于业主愿意支付的金额，以防止经理使用监控系统。在本文中，从有关如何量化VoI的文献综述开始，提出了一种数学公式，它允许人们评估何时以及在哪些特定条件下，例如先验信息和效用函数的适当组合，VoI变为负数。此外，为了说明该框架的工作原理，对 Streicker 桥（普林斯顿大学校园内配备光纤传感系统的人行天桥）的假设VoI进行了评估：结果显示了决定负VoI的主要因素如何是所有者和管理者这两个决策者的不同风险偏好。