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QIU Zixue
YAO Xingtian
School of Mechanical
Engineering,
Nantong University,
Nantong 226007, China
COSTAS Soutis
Department of
Mechanical Engineering,
The University of Sheffield,
Sheffield S1 3JD, UK
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STRUCTURAL HEALTH MONITORING IN
COMPOSITE MATERIALS USING
EMBEDDED SHAPE MEMORY
ALLOY (SMA) WIRE SENSOR*
Abstract:
Shape memory alloy (SMA) materials possess completely superelasticity or pseudoelasticity above the austenite finish temperature and many unique mechanical, thermal, thermal-mechanical and electrical properties compared with other conventional materials. Many studies have reported that the superelastic and hysteresis properties of the SMA materials can absorb energies coming from external excitations or sudden impacts. In addition, due to the special electrical properties of NiTi superelastic wires, they can also be used as strain-sensing element to monitor structural health conditions. Composite laminated specimens embedded with SMA wire sensors are fabricated and detailed testing system is designed such as multi-parameters measuring for impact and weak signal processing for SMA sensor. Low velocity impact test shows that SMA wire sensors embedded in fiber-reinforced plastic (FRP) laminate can be well used to monitor impact responses, such as the location of impact damage, impact degree, and strain distribution. Experimental results and theoretical predictions reveal almost the same. Comparing with other method, a simple, economic and reliable technique method monitoring important engineering structures on line is provided.
Key words:
Shape memory alloy (SMA) Structural health monitoring Sensor |