Shape memory alloy(SMA) is regarded as one promising intelligent/smart material element natively with thermo-sensor, shape recovery actuator and other material functions associated with thermoelastic phase transformation. Based on these unique material functions with SMAs, the authors have proposed a "smart bridge" design for active control for strength and vibration by changing the material properties of SMA embedded in the bridge structure by using the model specimen of TiNi/acrylic composite. By using direct electric heating for SMA, next two effects are investigated, i.e., (1) Self-strengthening effect by shape recovery of pre-strained TiNi wires as well as (2) Vibration control by changing the stiffness between lower temperature martensite (soft phase) and higher temperature austenite (hard phase). The deflection and vibration responses are measured by electrical strain gages attached on the bridge floor on which the model train goes through. Suppression effect for deflection as well as vibration control is experimentally confirmed.
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