Issue 48

H.S. Bedi et alii, Frattura ed Integrità Strutturale, 48 (2019) 571-576; DOI: 10.3221/IGF-ESIS.48.55 571 Focused on “Showcasing Structural Integrity Research in India” Interfacial shear strength of carbon nanotubes based hybrid composites: effect of loading rate Harpreet Singh Bedi, Beant Kaur Billing, Prabhat K. Agnihotri Mechanics of Advanced Materials Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Ropar, Punjab, India harpreet.bedi@iitrpr.ac.in, https://orcid.org/0000-0001-5662-0071 beant.kaur@iitrpr.ac.in prabhat@iitrpr.ac.in , https://orcid.org/0000-0002-8332-9279 A BSTRACT . Interfacial interaction is investigated between the two basic constituents in Carbon Fiber Reinforced Plastics (CFRPs). Efforts have been made to quantify the Interfacial Shear Strength (IFSS) between individual Carbon Fiber (CF) and epoxy matrix in CFRPs by performing single fiber micro-droplet debond test. Initially, IFSS of the epoxy composites reinforced with unsized or Heated Carbon Fiber (HCF) is assessed. Study is then extended to assess the IFSS of Carbon Nanotubes (CNTs) based CFRP hybrid composites. The hybrid composites are prepared by reinforcing epoxy matrix with CNT grafted Carbon Fibers (CNTCF). The versatile, simple and time effective method of chemical vapor deposition is used to synthesize CNTs directly on the surface of CF. IFSS is found to enhance after the inclusion of grafted CNTs in CFRP composites. Keeping in mind the application view point of CFRPs to put up with varying loads, effect of loading rate on the IFSS of CFRPs is also examined. To this end, both HCF/epoxy and CNTCF/epoxy composites are debonded at cross-head rates varying by two orders of magnitude and IFSS values are compared. Finally, scanning electron microscopy of debonded fibers is carried out to understand the interfacial failure mechanism in various composites. K EYWORDS . Carbon Fiber; CFRP; CNTs; Epoxy; IFSS; Microbond. Citation: Bedi, H.S., Billing, B.K.., Agnihotri, P.K., Interfacial shear strength of carbon nanotubes based hybrid composites: effect of loading rate, Frattura ed Integrità Strutturale, 48 (2019) 571-576. Received: 17.11.2018 Accepted: 16.02.2019 Published: 01.04.2019 Copyright: © 2019 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. I NTRODUCTION ue to increasing popularity and demand, Carbon Fiber Reinforced Plastics (CFRPs) are finding their way in applications that are likely to comprise high strain rate loading [1]. So, it becomes a necessity for CFRPs to be able to bear the complex environmental and loading conditions and their properties must not deteriorate at varying strain rates. Thus, to serve better the ever widening scope of engineering applications, it is vital for the composite materials to retain their mechanical performance at both quasi-static and/or dynamic loading conditions. This is D