Design methodology for cross-life structural health monitoring with unknown damage process

传统的结构健康监测通常用于a)监测旧的既有结构中已知的劣化过程及其时间发展，或者b)检查在具有高度创新性的新结构设计中所做的假设。然而，在这些应用中，监测期被限制在几个月到几年之间，并且明确定义了要监测的物理参数及其影响位置。在未来，长期的电子监测将成为基础设施建筑维护的重要工具，这与以下新的挑战有关：-监控期显著延长(长达几十年，直到结构的整个使用寿命)和-最初未知的损坏机制、发生时间和位置。这个子项目的目标是开发一种设计方法，可用于为这一新的应用领域可靠地设计监测系统。开发过程可以分为两个部分：一个是与建筑有关的，另一个是与测量系统有关的。界面是要测量的物理参数的定义。该项目的重点是优先方案第一阶段中与建筑有关的领域。要开发的方法首先应限于应用于预应力混凝土桥梁结构，即使基本方法可移植到其他类型的结构。该研究项目的科学挑战基于这样一个事实，即目前可用的测量方法只能以足够的分辨率监测有限的区域。由于监测将在结构使用寿命开始时开始，因此尚未对对象启动损坏过程。因此，完全基于传感器的监测需要在整个结构上建立密集的传感器网络，这在经济上和技术上都是不可行的。因此，子项目的科学知识效益是如何在最初未知的破坏机制、发生时间和位置的情况下设计可靠的测量概念。主要问题是哪些物理参数的分辨率(局部的、时间的、测量范围的)应记录在特定结构上。为了回答这个问题，采用了两种交互方法：与集群相关的方法和与对象相关的方法。与集群有关的办法是基于对现有类似结构的系统评价。为此，针对特定对象形成具有相似特征的比较组。与对象相关的方法是基于对特定建筑的专门分析。为此，现有结构的典型评估方法被置于未来测量技术的背景下。这两种方法都将被整合到方法学中，以便在BAB A2的过程中在Weserstrom桥上开发和测试。

Traditional structural health monitoring is usually used a) to monitor known deterioration processes and their temporal development in older existing structures or b) to check the assumptions made in the design of new structures with a high degree of innovation. In these applications, however, the monitoring period is limited to between a few months and a few years, and the physical parameters to be monitored and their effect locations are clearly defined. In the future, long-term electronic monitoring will become an important tool for the maintenance of infrastructure buildings, which is associated with the following new challenges: - significantly longer monitoring period (several decades up to the entire service life of the structure) and - initially unknown damage mechanism, time of occurrence and location. The objective of this sub-project is to develop a design methodology that can be used to reliably design a monitoring system for this new application area. The development process can be divided into two parts: one is related to the building and the other one is related to the measuring system. The interface is the definition of the physical parameters to be measured. The focus of this project is on the building-related area in phase 1 of the Priority Programme. The methodology to be developed shall be limited first to the application to prestressed concrete bridge structures, even though the basic methodology is transferable to other types of structures. The scientific challenge of the research project is based on the fact that presently available measurement methods can only monitor limited areas with sufficient resolution. Since monitoring is to begin at the start of the structure's service life, no damage processes have yet been initiated on the object. Complete sensor-based monitoring would, therefore, require a dense sensor network over the entire structure, which would be neither economically nor technically feasible. The scientific knowledge benefit of the sub-project is, therefore, how a reliable measurement concept can be designed with initially unknown damage mechanism, time of occurrence and location. The main question is which physical parameters with which resolution (local, temporal, measurement range) shall be recorded on a specific structure. To answer this question, two interacting approaches are applied: a cluster-related and an object-related approach. The cluster-related approach is based on the systematic evaluation of existing similar structures. For this purpose, a comparison group with similar characteristics is formed for the specific object. The object-related approach is based on a dedicated analysis of the specific building. For this purpose, the typical evaluation methods for existing structures are placed in the context of future measurement technologies. Both approaches are to be integrated into the methodology to be developed and tested on the Weserstrom bridge in the course of BAB A2.