The secondary strain growth phenomenon in elastic plane-strain rings

Abstract

Strain growth is a negative phenomenon in the use of explosion containment vessels. Previous studies mainly focused on the strain growth phenomenon caused by the single bending mode. In this paper, the secondary strain growth phenomenon caused by two bending modes is investigated. To study the strain growth phenomenon attributed to two bending modes, we simplified the explosion containment vessel to a plane-strain ring. The relationship between the thickness-to-radius ratio and preferred bending mode is obtained. The strain growth phenomenon of rings with different thickness-to-radius ratios subjected to the same internal impulse loading is studied through numerical simulations. It is shown that the excitation of two bending modes could lead to the occurrence of secondary strain growth, but it is not a sufficient condition for the secondary strain growth phenomenon. The secondary strain growth exhibits three distinct characteristic phases, namely the breathing vibration phase (Phase I), the regular bending vibration phase (Phase II) and the irregular bending vibration phase (Phase III). Phase I is dominated by the breathing mode response. Phase II is dominated by single bending mode and breathing mode, with only the first strain growth occurring in the ring. Phase III is dominated by two bending modes and breathing mode, and the strain could increase again because of the excitation of the second bending mode, leading to the secondary strain growth phenomenon.