Deformation and fracture of two-layer metal-plastic shells under internal shock loading

Criterion for Selecting Composite Materials for Explosion Containment Structures (Review)

“…In experiments with two-layer fiberglass shells, an increase in their specific strength and deformability was confirmed (as in [18]). In experiments with certain failure during the first extension, the following ultimate hoop strains for the shells were obtained: ε el = 3.3% (Kh fiber), 3.7% (R fiber), 4.55-4.8% (VMP fiber), and 4.7-5.2% (VM-1 fiber, the result agrees with [21,23,24]).…”

“…This effect is the most pronounced for Kh fiber shells with halved relative thickness, which agrees qual- [26], points 4 to TS-8/3-T fiberglass cloth [20]; points 5 refer to TS-8/3-T fiberglass cloth [18], points 6 to VM-1 for ϕ1 = ±35 and ϕ2 = 90 • at a thickness ratio of 2 : 1 [27], points 7 to VM-1 with ϕ = 90 • or ϕ1 = ±45 and ϕ2 = 90 • at a thickness ratio 2 : 1 [28], and points 8 to basalt plastic-steel shells estimated from the data of [19]; for the twolayer (composite-steel) shells, the sound speed was calculated assuming that the steel layer is an inert mass because of its minor effect on energy absorption.…”

“…In experimental studies of simple cylindrical composite shells of revolution under internal explosive loading, it was established that a criterion of their strength can be the ultimate (at the failure threshold) hoop strain of the shell, which under dynamic conditions is 2-2.5 times higher than the similar quasistatic value for the employed composite [13,14,18,21,23,31]. It is shown that the ultimate strain of fiberglass and organic plastic materials depends on the strain rate [24]; at a strain rate of ≈1 000 sec −1 , it approaches the ultimate strain of defect-free fiber.…”

“…The tests were performed with open cylindrical shells of various types and open cylindrical fiberglass shells in which steel shells (St. 20 steel) were inserted with a gap of not more than 0.2 mm, The steel shells had an inner diameter 2R 1 = 295 mm, a relative thickness δ 1 /R 1 = 1.4%, and a length 4R, and the thicknesses ratio of the shells was 0.2-0.3. The importance of reinforcing fiberglass layers by a layer of ductile steel with a definite thickness ratio to increase the specific strength, which is evaluated by the parameter ξ was first noted in [18].…”

Dynamic Strength of Fiber Glass Shells

“…There was experimentalb determined relation between thicknesses of fiber glass and steel (steel layer with thickness of 2118 to thickness of fiber glass), when quick damping of radial vibrations of the shell took place, and that was the reason of achievement of mentioned increase [9]. In work [lo] such effect was achieved after addition of a copper foil layer adjacent to fiber glass.…”