Evaluation of the damage suppression effect of Ti-Ni shape memory alloy foils embedded in carbon fiber reinforced plastic laminates

Abstract

In this research, shape memory alloy (SMA) foils were embedded into carbon fiber reinforced plastic (CFRP) cross-ply laminates. When the tensile pre-strained SMA foil is heated, the SMA produces appropriate compressive stress (recovery stress) to suppress the transverse cracks in the laminates. In order to investigate the damage suppression effect, tensile loading-unloading tests were conducted for the CFRP cross-ply laminates. The test results implied that the recovery stress of embedded SMA foil suppressed the occurrence and the progress of the transverse crack. Then, to confirm that the damage suppression effect was caused by the embedded SMA foil, the onedimensional (1D) shear-lag model considering the behavior of SMA was newly derived. Using this model, the progress of transverse crack density was predicted probabilistically. The simulation results showed the same tendency as the experimental results. As a result, it was proved that the embedment of SMA foils into CFRP laminates is effective to suppress the occurrence and growth of the transverse cracks.

Impact damage resistance and damage suppression properties of shape memory alloys in hybrid composites—a review

“…When a pre-strained SMA fiber or foil embedded in the laminate is heated, it tends to shrink to its original shape and to instantaneously generate recovery compressive forces along the pre-strained direction in the composite matrix, which are effective at suppressing the initiation and growth of transverse cracks [42][43][44]. This compressive force is generated by the martensitic phase transformation from the SIM phase to the austenite phase.…”

“…Amano et al [42,43] also treated the SMA foils with a 10% NaOH anodic oxidation in order to improve the adhesion performance of the epoxy resin. The same authors [44] cleaned and roughened with 3% fluoride acid-15% nitric acid the SMA (NiTi) foils in order to remove the oxide film created when the material was mechanically rolled.…”

“…The SMA foils were also cleaned using a solvent when the laminates were manufactured. Amano et al [42,43] and Ogisu et al [44,45] used an epoxy adhesive film to increase the adhesion between the CFRP laminate and SMA (TiNi) foils. In Jang and Kishi [58] the surfaces of the SMA (TiNi) wires were chemically etched for 10 min in 3% HF + 15% HNO 3 solution in order to obtain strong adhesion between the SMA wires and a CFRP matrix.…”

“…Amano et al [42,43] developed a system for damage detection and suppression based on embedding pre-strained SMA (TiNi) foils and small-diameter FBG sensors simultaneously in where Ad represents an epoxy adhesive film. The smalldiameter FBG sensors were embodied into the 0 • ply along the reinforcement carbon fibers in contact with the 90 • ply, so that it was sensitive to transverse cracks running through the thickness and width of the 90 • ply.…”

Evaluation of Crack Suppression Effect of TiNi SMA Foil Embedded in CFRP Cross-Ply Laminates with Embedded Small-Diameter FBG Sensor

“…As the TiNi SMA has a Rhombohedral phase in addition to martensite and austenite phases, the authors proposed a new model, extended brinson model, in the previous paper (9), (10) . According to Table 1 Mechanical properties of the CFRP unidirectional laminates (T300/F593, Hexcel).…”