PSI - Issue 13

V. Moskvichev / Procedia Structural Integrity 13 (2018) 2114–2119 V. Moskvichev / Structural Integrity Procedia 00 (2018) 000 – 000

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Risk assessment was performed on the basis of an analysis of possible mechanisms of MCOPV destruction. The fracture event of the MCOPV decays into two events: the destruction event of the liner and the destruction event of the power composite shell. In the first case, the main parameter controlling the state of the liner is deformation, and in the second case the stresses in the composite shell are the determining parameter. a) b)

Fig. 5. A metal-lined composite pressure vessel: calculation scheme (a), functions of reliability depending on the time and the stress level σ p / σ c (b)

Reliability functions R(τ, σ) for MCOPV in orbit are shown in Fig. 5b. As it is seen from the figure, while ensuring the homogeneity of the properties of the composite sheath and operating stresses not exceeding 0.5 of the strength level of the composite material, the reliability of MCOPV is ensured at a level of at least 0.999 at the end of operation time in orbit. When the relative stresses level is increased to 0.6, high reliability is ensured only in the first 500 hours of operation. The load level of more than 0.6 is unacceptable for this MCOPV. Values of the level of risk of depressurization and destruction are in the range of R(P, τ) = 1,3 · 10 -6 … 2,4·10 -8 .

References

V.V. Moskvichev: Fundamentals of structural strength of technical systems and engineering structures (Nauka, Russia 2002). A.M. Lepikhin, N.A. Makhutov, V.V. Moskvichev, A.P. Cherniaev: Probabilistic risk analysis of technical system structures (Nauka, Russia 2003). V.V. Moskvichev, N.A. Makhutov, A.P. Cherniaev: The fracture toughness and mechanical properties of structural materials (Nauka, Russia 2002). A.M. Lepikhin, N.A. Makhutov, V.V. Moskvichev, S.V. Doronin: Fatigue and Fracture of Engrg. Mater, and Struct. Vol. 23 (2000), p. 395.

A.M. Lepikhin, S.V. Doronin, V.V. Moskvichev: Theoret. and applied fract. mech. Vol. 29 (1998), p. 103. A.E. Burov, A.M. Lepikhin, V.V. Moskvichev, N.A. Makhutov: Strength of Materials. Vol. 49. № 5, p. 666.