Fabrication and characterization of SMA hybrid composites

Abstract

Results from an effort to fabrication shape memory alloy hybrid composite (SMAHC) test specimens and characterize the material system are presented in this study. The SMAHC specimens are conventional composite structures with an embedded SMA constituent. The fabrication and characterization work was undertaken to better understand the mechanics of the material system, address fabrication issues cited in the literature, and provide specimens for experimentM validation of a recently developed thermomechanical model for SMAHC structures. Processes and hardware developed for fabrication of the SMAHC specimens are described. Fabrication of a SMAHC laminate with quasi-isotropic lamination and ribbon-type Nitinol actuators embedded in the 0 °layers is presented. Beam specimens are machined from the laminate and are the fiJcus of recent work, but the processes and hardware are readily extensible to more practical structures. Results of thermomechanical property testing on the composite matrix and Nitinol ribbon are presented. Test results from the Nitinol include stress-strain behavior, modulus versus temperature, and constrained recovery stress versus temperature and thermal cycle. Complex thermomechanical behaviors of the Nitinol and composite matrix are demonstrated, which have significant implications for modeling of SMAHC structures.

Finite Element Analysis of Adaptive-Stiffening and Shape-Control SMA Hybrid Composites

“…Extensive experimental and modeling work has also been conducted on active SMA polymer composites by Turner and his collaborators at NASA Langley Research Center [28][29][30][31][32][33]. Figure 1 shows a conceptual airplane with morphing airfoil made of shape memory alloy hybrid composite and the adaptive stiffening prototype beam at NASA undergoing a temperature ramp test.…”

Vibration characteristics of laminated composite plates with embedded shape memory alloys

“…They have been used as "smart" components embedded into the conventional resins or composites so as to obtain active abilities, including in tunable stiffness, damping capacity, shape-controllable active surfaces and self-healing capability. Many works have been done and shown that SMAs have significant potential applications for vibration control and structural control [2][3][4][5][6][7][8]. Although two-dimension weaving metal wires, such as stainless wires, are common in industry applications, to the authors' knowledge, a preliminary study of weaving SMA wires has been reported by Boussu et al [7].…”

Working principle of bio-inspired shape memory alloy composite actuators

“…Turner et al have demonstrated a glassepoxy laminate composite with embedded SMA ribbon [1] which exhibited characteristics useful for adaptive stiffening of aerospace structures. Shahinpoor and Wang have proposed designs for large-motion from SMA actuators [2].…”