Structural health monitoring systems for civil and architectural structures: LVDT-taut-wire baselines, crack monitoring devices, and strain based deflection monitoring algorithms

In this age of computers and electronics, we become increasingly aware of all the new information we can collect about our surroundings. The medical industry has fully embraced the use of this technology to help diagnose problems with our health. The civil engineering profession is only now beginning the steps toward using structural health monitoring (SHM) for the purpose of extending the productive lives of our infrastructure. The ubiquitous use of SHM will reap the benefit of providing a rational method to prioritize expenditure allocation to maintain our deteriorating facilities. Since SHM is far from ubiquitous, the lessons learned during any instrumentation program provide a significant contribution to the SHM field.;This dissertation begins by showing structural engineers a few of the tools of the trade that can be used in a SHM program. To help open the instrumentation world to engineers and scientists, an example of the process by which to design an economical crack gauge is discussed. This dissertation also contributes new information to the SHM field. First, a simple design process for an LVDT-Taut-Wire baseline system that measures vertical deflections on long and short span beams is established. Second, a method by which to pre-determine the magnitude of expected error caused by real data for a strain based deflection monitoring algorithm is presented. Both of these contributions will help to more quickly design SHM systems and provide the user reasonable confidence of the systems performance before the system is installed. Finally, a brief discussion of how some of the key lessons learned will be incorporated into four SHM projects is presented.