Effect of Carbon Nanofibers on the Strain Rate and Interlaminar Shear Strength of Carbon/Epoxy Composites

Abstract

The static bending properties, different strain rates and interlaminar shear strength (ILSS) of carbon-fiber-reinforced polymers (CFRP) with two epoxy resins nano-enhanced with carbon nanofibers (CNFs) are studied. The effect on ILSS behavior from aggressive environments, such as hydrochloric acid (HCl), sodium hydroxide (NaOH), water and temperature, are also analyzed. The laminates with Sicomin resin and 0.75 wt.% CNFs and with Ebalta resin with 0.5 wt.% CNFs show significant improvements in terms of bending stress and bending stiffness, up to 10%. The values of ILLS increase for higher values of strain rate, and in both resins, the nano-enhanced laminates with CNFs show better results to strain-rate sensitivity. A linear relationship between the logarithm of the strain rate was determined to predict the bending stress, bending stiffness, bending strain and ILSS for all laminates. The aggressive solutions significantly affect the ILSS, and their effects are strongly dependent on the concentration. Nevertheless, the alkaline solution promotes higher decreases in ILSS and the addition of CNFs is not beneficial. Regardless of the immersion in water or exposure to high temperatures a decrease in ILSS is observed, but, in this case, CNF content reduces the degradation of the laminates.

Fatigue and Fracture Behavior of Composite Materials

“…In the present Special Issue, the contributions can be divided into different topics: those aimed at modelling the composite behaviour [1,2], those aimed at evaluating the material response via classic [3,4] and innovative methodologies involving the use of experimental techniques [5][6][7], and one focused on presenting new functions for composite repair [8].…”

“…Experimental characterisation is the common denominator between studying material response and validating theoretical and numerical fatigue models. In the work of Santos et al [3], the behaviour of carbon laminates nano-reinforced with CNFs was explored under different testing conditions (bending tests and interlaminar shear tests in different environments such as hydrochloric acid, sodium hydroxide, water, and temperature). The obtained results demonstrate the relevant improvements in bending stress and bending stiffness due to the incorporation of CNFs.…”

Interlaminar Properties of Prepregs Reinforced with Multiwalled Carbon Nanotubes/Graphene Oxide

“…CFRP composites are preferred as advanced materials due to their lightweight, highstrength, and structural design capabilities [1][2][3]. They find extensive use in industrial fields, notably aerospace [4].…”

Analysis of the Self-Healing Capability of Thermoplastic Elastomer Capsules in a Polymeric Beam Structure Based on Strain Energy Release Behaviour during Crack Growth

“…Through the use of origami-inspired capsules activated by strain removal, the capacity for self-healing within components or structures can be significantly revolutionized. Any type of surface or subsurface damage can trigger the initiation of strain removal in the entire component, with the capsules unfolding and expanding to facilitate strain removal at a subsurface level [ 11 , 12 , 13 , 14 , 15 ].…”