Influence of shear plugging in the energy absorbed by thin carbon-fibre laminates subjected to high-velocity impacts

Abstract

a b s t r a c tThis work examines the energy-absorption process in thin woven laminates made from carbon fibres, with the aim of analysing the energy employed in the formation of a shear plug. This study was conducted with a simplified model which considered five energy-absorption mechanisms. The model was validated with experimental tests and numerical simulations, with regard to the residual velocity of the projectile and perforation velocity. The model makes it possible to evaluate the influence of the shear plugging in laminates of different thickness. It has been demonstrated that this energy-absorption mechanism needs to be considered in the analysis. The main energy-absorption mechanisms for impact at low velocity (i.e. below the perforation velocity) are related to the elastic deformation of fibres and shear plugging, whereas when a higher impact velocity is considered (i.e. above the perforation velocity) such mechanisms are related to the acceleration field of the laminate and the shear plugging.

Energy absorption of repaired composite laminates subjected to impact loading

“…If the shear stress exceeds shear plugging strength of the laminate, then failure occurs due to shear plugging. The energy absorbed by the laminate for the formation of shear plug is calculated [21],…”

Preparation and properties of a p‐aramid fabric composite impregnated with a magnetorheological fluid for body armor applications

“…It was also determined that PU in the p ‐aramid fabrics increased the energy absorption during the puncture test. It appears that PU, a polymer with high toughness, plays a significant role in not only protecting the p ‐aramid fiber from fracturing but also in increasing the energy absorption of the fabric composite by inducing delamination and matrix cracking . The MRF further raised the energy absorption under a magnetic field in the MRF/ p ‐aramid fabric, as well as in the PU‐MRF/ p ‐aramid fabric composite.…”

High velocity impact tests on high temperature carbon-carbon composites

“…RCC composites are essentially constituted by rayon fibers in carbon matrix, and the more recent ACC (based on PAN-based carbon reinforcements) are gradually replacing RCC structures. Due to their lightweight characteristics and high-temperature strength, general C/C are suitable candidate materials to satisfy the very stringent design requirements of reusable space vehicles and have been used as thermal protection systems (TPS) in airframes subjected to high temperature in hypersonic and reusable launch vehicles like the Space Shuttle [4,5] Although the mechanical and thermal properties of C/C composites are nowadays fairly well understood [6][7][8] and extensive investigations have been performed about the dynamic mechanical properties of "conventional" types of composites (i.e., resin matrix composites) [9][10][11][12][13][14][15][16][17][18][19], the knowledge about the high-speed impact dynamic behavior of C/C composites is still incomplete. Several research groups have studied the effect of the temperature on the dynamic properties and the impact damage at low temperature [20][21][22][23] and cryogenic environment [24,25], but the temperature range usually limited between -150°C and 150°C due to the partial heat resistance capability of common composite materials.…”