Tensile characterization of graphene nanoplatelet/shape memory alloy/epoxy composites using digital and thermal imaging

Abstract

This article explores the tensile deformation and failure characteristics of a hybrid composite where microscale shape memory alloy (SMA) fibers and nanoscale graphene nanoplatelets (GNPs) were used to reinforce a ductile epoxy matrix. First, the GNPs were incorporated into epoxy system using a hybrid dispersion technique at various weight percentages ranging from 0.25 to 2.50 wt%. The mechanical properties of GNP composites were investigated using monotonic uniaxial tensile tests to failure and were compared to neat epoxy. The GNP concentration that resulted in highest enhancement in tensile properties of the epoxy was identified. Then, the GNP/SMA/epoxy composites were fabricated using a vacuum assisted hand lay-up technique. The composites were reinforced with SMA fibers at 50% volume ratio and an optimal GNP concentration was added. The tensile response of the developed composites was characterized using full-field strain measurements captured by a digital image correlation system, while simultaneously the thermal response of the composites was monitored through measurements of an infrared camera. The tensile properties, superelastic response, and failure mechanisms of the developed composites were discussed. Results shows that the developed GNP/SMA/ epoxy composites exhibit excellent superelastic characteristics with a maximum strength of 533 MPa and failure elongation of 12.5%.

Non‐isothermal DSC curing kinetics study of silicone‐modified epoxy/ABS/GO nanocomposite

“…[1][2][3][4] Epoxy resins are among the most widely used substances in the production of polymeric composites. [5][6][7] The mechanical and thermal properties of epoxy resins are related to the microstructure and cross-linked network formed during the curing process. On the other hand, the network structure of the final product and the kinetic of the curing reaction are highly dependent on the structure and specifications of the curing agent, additives as well as the curing conditions.…”

“…The application of polymer‐layered nanoparticle composites has been recently increased in engineering structures due to the development of beneficial and functional properties like their high strength‐to‐weight ratio, corrosion resistance, proper thermal insulation, low thermal expansion, etc 1–4 . Epoxy resins are among the most widely used substances in the production of polymeric composites 5–7 . The mechanical and thermal properties of epoxy resins are related to the microstructure and cross‐linked network formed during the curing process.…”

Covalent crosslinks turn natural Eucommia ulmoides gum/polybutene‐1 composites into multiple shape memory materials

“…[3,7,8] In general, the original shape of SMPs is manipulated during processing while temporary shapes are programmed under certain external conditions. [9,10] The heat-triggered SMPs (HSMPs) have been paid much attention in the past decades and experienced explosive advances recently, [2,[11][12][13] involving novel strategies to fabricate SMPs with multiple stimulus, degradable and biocompatible SMPs, and enhancement of SMPs, [14,15] and so forth. However, it is still quite challenging to prepare HSMPs with multiple shape memory effects (SME) realized through several phase transitions or broadened glass transition via chemical synthesis, which limits its further development.…”