Objective This paper studies the damage modes of targets simultaneously subjected to multiple damage elements by analyzing the damage characteristics of a cylindrical shell structure subject to a double underwater explosion (UNDEX).

Methods First, a finite element model of the cylindrical shell is established, then the arbitrary Lagrangian−Eulerian (ALE) method is used to investigate its damage characteristics when subject to UNDEX with single or dual explosion sources, and the damage effects are evaluated in terms of the structural fracture area, maximum vertical displacement and extent of plastic strain area, and the 500 kg TNT charge is calculated and analyzed.

Results The results show that when the standoff distance of dual explosion source is 1 m, the damage to the outer cylindrical shell is more serious when the standoff distance of dual explosion sources is equal to that of the single explosion source, but the damage to the inner cylindrical shell is less than that of the single explosion source. At the same time, with the increase in standoff distance of the two TNT charges, especially when the standoff distance is greater than 3 m, the damage effects on the cylindrical shell structure become weaker.

Conclusions By calculating the damage to a cylindrical shell structure by UNDEX under different initial parameters, the general rules of damage to cylindrical shell structures by single and dual explosion sources are given, which can provide references for enhancing the power of underwater weapons.