Edge Delamination and Residual Properties of Drilled Carbon Fiber Composites with and without Short-Aramid-Fiber Interleaf

Abstract

Edge delamination is frequently observed in carbon fiber reinforced plastic (CFRP) laminates after machining, due to the low fracture toughness of the resin interfaces between carbon fiber plies. In this study, the effects of incorporating tough aramid fibers into the brittle CFRP system are quantified by measuring the residual properties of bolted CFRP. By adding short-aramid-fiber interleaves in CFRP laminates, the residual tensile strength have been substantially increased by 14 % for twill-weave laminates and 45 % for unidirectional laminates respectively. Moreover, tensile failure was observed as the major mode of toughened laminates, in contrast to shear failure of plain laminates. The qualitative FEM results agreed well with the experimental results that edge delamination would cause relatively higher shear stress and therefore alter the failure mode from tensile failure to shear failure.

A novel mica‐based composite with hybrid aramid fibers for electrical insulating applications: largely improved mechanical properties and moisture resistance

“…For the best case of 50%A‐M paper (Fig. (f)), fibrids can totally wrap flocs and mica flakes together, which is very favorable for stress transfer …”

Compression‐after‐impact properties of carbon fiber composites with interlays of Aramid pulp micro‐/nanofibers

“…Even the residual tensile strength was increased by 14% for twill‐weave laminates and 45% for unidirectional laminates. [ 35 ] A third study from the same university by Yuan et al [ 20 ] focused on the improvement of the damaged area caused by the low‐velocity impact, a 50.8% decrease in back‐face impact deflection and 38.6% increased CAI strength. Yuan et al [ 19 ] also explained that short Aramid fiber nonwoven veil interfacial toughening is achieved by altering 3D interfacial structures between carbon fiber piles and by restraining out‐of‐plane movements of free fiber ends.…”

Influences of dispersion types and area densities of chopped fiber‐based interfacial reinforcements on mechanical properties of sandwich structures

“…Fiber-reinforced polymers (FRPs) have been increasingly used in aerospace [1], marine [2], construction [3], rail transit, and other transportation applications [4] due to high specific stiffness and strength. However, compared with traditional materials, FRPs suffer from the disadvantages of low residual strength and energy absorption after impact owing to delamination [5,6]. Sandwich structure composite material prepared by placing a foam core between two layers of FRPs can partly solve the above problems.…”

“…The layer between adhesive skin and core material plays an important role in the mechanical properties of sandwich material. Cracks are prone to expansion upon an external load, leading to delamination of the interlayer between core and surface and then completely failing the sandwich structure [6]. In addition, the interlayers of laminates and sandwich structures commonly have poor performance.…”