A Base Isolation Device Using Shape Memory Alloy Wires

Abstract

In this study, a base isolation device using pseudoelastic shape memory alloy (SMA) wires is developed. A base isolation device using softening spring restricts acceleration transmission from the source of vibration so that pseudoelastic SMAs, which have origin-oriented hysteretic restoring forces, are utilized as softening springs rather than damping materials. Two SMA wires are used as the spring arranged as they as buckled when the spring is subjected to a compressive load. Therefore, the spring's restoring force shows remarkable softening characteristic due to material and geometric nonlinearity. Furthermore, base isolation effect based on output acceleration is investigated experimentally and analytically.