Stiffness Change with Temperature in Glass Fiber Reinforced Composite Laminates Embedded with SMA Wires

Abstract

This paper discusses change in stiffnesses with temperature of composite laminates in which TiNi shape memory wires are embedded. Young's modulus in Shape Memory Alloys (SMA) markedly increases with temperature passing through its phase transition temperature. GF laminate embedded with SMA wires can therefore increase its stiffnesses with temperature. The inplane stiffnesses of UD laminates with SMA wires are measured, and it is shown that the SMA does have influences on all inplane elastic coefficients. The stiffnesses of UD material can be used as the basic ingredients for the classical lamination theory in which stiffness change with temperature can be accounted for. Specific examples of symmetric laminates having layers with and without SMA are calculated. This paper can serve as a base for stiffness design of composite laminates possessing such novel function that the laminate can increase its rigidity by e. g., electric current and therefore can avoid vibration resonance.