Effect of block copolymer nano-reinforcements on the low velocity impact response of sandwich structures

Abstract

is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. a b s t r a c tSandwich composites with fibre reinforced plastic (FRP) facesheets have emerged as a major class of lightweight structural materials in a wide range of engineering fields including aerospace, automotive and marine structures. This is due to attractive mechanical properties such as high specific stiffness and high strength. However, sandwich structures are susceptible to damage caused by impact. The objective of this paper is to evaluate the dynamic response of sandwich composites based on Kevlar fibre reinforced epoxy and Rohacell Ò foam. The improvement in impact performance of these sandwich structures that can be achieved by the addition of nanoparticles in the resin matrix is investigated. Nanostrength Ò , an acrylate triblock copolymer that self-assembles in the nanometer scale is added to the epoxy matrix. The effect of the nano-reinforcements on flat sandwich plates under low velocity impact is investigated at different scales. An instrumented drop tower setup is used for the low velocity impact tests of the sandwich plates with neat or nano-reinforced epoxy matrix, at different energies. The macroscopic response of the sandwich structure and the microscopic phenomena involved in dissipating the impact energy are identified and compared for sandwich plates with and without nanoparticles.

Inclusion of a thermoplastic phase to improve impact and post-impact performances of carbon fibre reinforced thermosetting composites — A review

“…Denneulin et al [73] reported significantly increased impact strength and reduced damage area for a concentration of 10 wt.% of Nanostrength®. Ramakrishnan et al [74] achieved similar results with sandwich structures, due to the nano-cavitation and the shear yielding caused by the presence of the nano-particles.…”

Experimental study of the medium velocity impact response of sandwich panels with different cores

“…Four bolts were tightened to a torque of 5 N•m in order to provide a consistent clamping condition from test to test. Similar circular fixtures were used to evaluate the low velocity impact response of sandwich panels [2,31] and composite laminates [32,33] under drop weight impact tests. A protective cage, as shown in Fig.…”

“…Sandwich structures are lightweight composite materials that have been widely used in numerous application fields such as aerospace, marine, automotive, and energy industries for their desirable properties like high specific bending stiffness, excellent thermal insulation, acoustic damping, etc. However, sandwich composite structures are susceptible to impact loading and may be subjected to different impacts such as tool drops, bird strikes, hail stones, and runway debris during the service life [2]. These impacts may cause significant damage, such as local core crushing and debonding of the facesheet from the core, which severely compromises the structural integrity of the sandwich panel [3].…”

Epoxy formulation including an acrylic triblock copolymer adapted for use in filament winding

“…The random copolymer containing DMA provides a better miscibility of the shell with several epoxy formulations . Addition of small amounts of these block copolymers produces a significant increase of the fracture resistance of neat epoxy formulations and their composites .…”