PSI - Issue 28

L.A. Igumnov et al. / Procedia Structural Integrity 28 (2020) 1909–1917 Author name / Structural Integrity Procedia 00 (2019) 000–000

1913

5

Table 3 – Calculation Results and Experimental Data for the Metal-Plastic Shells on the Basis of Glass Fibers

Condition of the shell

Reinforcement structure

constant strength characteristics

strain rate dependence of strength characteristics

R , m

h/R , %

m , g

experiment

e 22 , %

t , ms

e 22 , %

t , ms

e 22 , %

t , ms

Did not fail, damage of steel shell

Failed in the first period of vibrations

Did not fail, has partial damage of all layers

(±45;90 0 ) 8

0.1529

7.11

334.5

3.9

95

3.94

130

2.95

87

Table 4 - Calculation Results for the Metal-Plastic Shells with various reinforcement schemes

Condition of the shell

Reinforcement Structure

R , m

h/R , %

m , g

strain rate dependence of strength characteristics

constant strength characteristics

Failed in the first period of vibration in tension Failed in the first period of vibration in tension Failed in the first period of vibration in compression Failed in the first period of vibration in tension Failed in the first period of vibration in tension

Failed in the first period of vibration in tension

(±30 0 )

0.1529

7.11

334.5

(±45 0 )

0.1529

7.11

334.5

Did not fail, has partial damage of all layers

Failed in the first period of vibration in compression

(90 0 )

0.1529

7.11

334.5

(±30;90 0 )

0.1529

7.11

334.5

Did not fail, has partial damage of all layers

(±45;90 0 ) Did not fail, has partial damage of all layers As can be seen from Table 4, the strain rate dependent strength characteristics taken into account qualitatively change the failure pattern of cylindrical shells, and the shells with the circumferential reinforcement scheme have the lowest load-carrying capacity. Figures 2-6 illustrate the process of progressive failure in time of metal-plastic shells with different reinforcement schemes loaded by an explosive charge of mass of m =334.5 g for the cases of constant strength characteristics (a) and their dependence on strain rate (b). On the Figures, the white, gray, and black backgrounds correspond to the zones without any failure, with a failure of matrix, and with a failure of fibers, respectively. The evolution in time of the zones of local failure of a binder and fibers in the cylindrical shells with a uniform angle-ply winding at the angles ±30, ±45, and 90° with the generatrix of the shell is shown on Figs. 2-4, respectively. One can see a significant effect of the reinforcement angle and the strain rate dependence of strength characteristics on the character and size of failure zones of the shell, and the time of its final failure at the time of fibers failure across the entire thickness of the shells. 0.1529 7.11 334.5