Tensile and fatigue behavior of polymer composites reinforced with superelastic SMA strands

• Published in: Smart materials and structures 2018-06, Vol.27 (6), p.65003
• Main Authors: Daghash, Sherif M, Ozbulut, Osman E
• Format: Article
• Language: English
• Subjects: cyclic and fatigue behavior; fiber-reinforced polymers; shape memory alloys; SMA strands; SMA-FRP composite
• ISSN: 0964-1726; 1361-665X
• DOI: 10.1088/1361-665X/aabcb1

This study explores the use of superelastic shape memory alloy (SMA) strands, which consist of seven individual small-diameter wires, in an epoxy matrix and characterizes the tensile and fatigue responses of the developed SMA/epoxy composites. Using a vacuum assisted hand lay-up technique, twelve SMA fiber reinforced polymer (FRP) specimens were fabricated. The developed SMA-FRP composites had a fiber volume ratio of 50%. Tensile response of SMA-FRP specimens were characterized under both monotonic loading and increasing amplitude loading and unloading cycles. The degradation in superelastic properties of the developed SMA-FRP composites during fatigue loading at different strain amplitudes was investigated. The effect of loading rate on the fatigue response of SMA-FRP composites was also explored. In addition, fractured specimens were examined using the scanning electron microscopy (SEM) technique to study the failure mechanisms of the tested specimens. A good interfacial bonding between the SMA strands and epoxy matrix was observed. The developed SMA-FRP composites exhibited good superelastic behavior at different strain amplitudes up to at least 800 cycle after which significant degradation occurred.