Wireless sensing for structural health monitoring

• Main Author: Lin, Daotong.
• Other Authors: Yang Yaowen
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Civil engineering::Structures and design
• Online Access: http://hdl.handle.net/10356/15669
• Institution: Nanyang Technological University

In Civil Engineering areas such as Structural Health Monitoring and Parameter Identification has been making use of Smart Materials such as Lead Zirconate Titanate or PZT for some time. Its usage has significantly increased over the years in fields, such as ultrasonic sensors, piezoceramic stacks, bimorphs, micro-positioning and even in parts of robotic controls. PZT is one of the more advanced and popular models. It is a small, brittle chip which doubles as both an actuator and sensor. It is permanently bonded or embedded onto the structural substrate and is capable of vibrating at ultra sonic frequencies with electrical voltages passed into it. With the intrinsic electro-mechanical coupling, PZT actuators are highly sensitive, even to very small changes in the mechanical properties of the host structure. This enables the direct monitoring of structural health. As the usage of PZT for SHM increases, we can start to explore the ways to improve the ways in which the data can be used. Vibrations are an element present in SHM which can be examined closer in detail. Another monitoring information useful to people would be the location of the damage with respect to the sensor, part of this project will examine if it is possible and/or practical to achieve such information. Wireless technology is also a relatively recent development which could have positive effects on the practice of SHM, it can be used here in conjunction with the PZT for greater utility. As PZTs currently use copper wires, this arrangement may result in erroneous data due to the resistance within the wires. One key idea involves long distance data gathering and achieving better results by removing the physical component through using wireless technology.