Dynamic shear strength of S2 glass fiber reinforced polymer composites under shock compression

Abstract

In the present paper, a series of plate impact shock-reshock and shock-release experiments were conducted to study the critical shear strength of a S2 glass fiber reinforced polymer (GRP) composite under shock compression levels ranging from 0.8 to 1.8 GPa. The GRP was fabricated at ARL, Aberdeen, using S2 glass woven roving in a Cycom 4102 polyester resin matrix. The experiments were conducted by using an 82.5 mm bore single-stage gas gun at Case Western Reserve University. In order to conduct shock-reshock and shock-release experiments a dual flyer plate assembly was utilized. The shock-reshock experiments were conducted by using a projectile faced with GRP and backed with a relatively high shock impedance Al 6061-T6 plate; while for the shock-release experiments the GRP was backed by a relatively lower impedance polymethyl methacrylate backup flyer plate. A multibeam velocity interferometer was used to measure the particle velocity profile at the rear surface of the target plate. By using self-consistent technique procedure described by Asay and Chabbildas [Shock Waves and High-Strain-Rate Phenomena, in Metals, edited by M. M. Myers and L. E. Murr (Plenum, New York, 1981), pp. 417–431], the critical shear strength of the GRP (2τc) was determined for impact stresses in the range of 0.8 to 1.8 GPa. The results show that the critical shear strength of the GRP is increased from 0.108 GPa to 0.682 GPa when the impact stress is increased from 0.8 to 1.8 GPa. The increase in critical shear strength may be attributed to rate-dependence and/or pressure dependent yield behavior of the GRP.

Determination of dynamic shear strength of 2024 aluminum alloy under shock compression

“…6 illustrates the calculation of the critical shear strength of the 2024 aluminum alloy under different preshocked states by self-consistent method. The critical shear strength can be obtained by following four steps: 16,26 (i) State 2 and state 4 are defined as maximum or minimum shear stress states at the reshock path or the release path because the Lagrangian wave velocity reduces to the bulk wave speed at those states; (ii) A tangent line can be drawn at the state 2 or state 4, and the extension of the tangent line can be made; (iii) The maximum stress point A or the minimum stress point B can be determined by the intersection point between the extending line and the vertical line passing the preshocked point; (iv) Finally, the critical shear strengths can be calculated by equation (7).…”

“…If the gauges record the histories of the stress, the particle velocity fields can be derived from the equation (16). Then strain and the specific internal energy can be obtained from the equation (15) and the equation (17), respectively.…”

“…12 through a simplified analysis. In view of the fact that the calibration of lateral gauge is uncertainty, self-consistent technique [13][14][15][16][17] was used in the present study to determine the shear strength of 2024 aluminum alloy since it has advantages over the lateral stress gauge technique.…”

Dynamic fracture of carbon nanotube/epoxy composites under high strain-rate loading

“…The working principles of dynamic loading, measurement and data interpretation, and representative examples can be found in Refs. [1][2][3][4][5][6][7][8]22,32]. Flyer plate impact experiments are conducted with a 10-mm bore, single-stage, tabletop gas gun to investigate dynamic compression and tension responses of the CNT/epoxy composites.…”

“…Previous studies investigated shock response of the elastomer polychloroprene [1], compression and release behaviors, and dynamic shear strengths of glass fiber-reinforced polymer composites [2,3], shock equation of state of carbon-fiber epoxy composite [4], the effect of orientation on the shock response of a carbon fiber-epoxy composite [5], dynamic tensile strengths of a glass fiber reinforced epoxy composite [6] and of organic fiber-reinforced epoxy microcomposites [7], and punch damage of a woven carbon fiber reinforced-epoxy composite with carbon nanotube additions [8].…”