Objectives  The aim of this paper is to address the equivalence of damage characteristics in a ship's cabin subjected to explosion by naval gun attack, and gain a better model of the damage effects of a full-scale ship cabin on the hull structure, equipment and crew.

  Methods  The test and data analysis for the static explosion of a projectile in a full-scale warship cabin are carried out, and the processing method of test data from the internal explosion in the cabin (i.e. overpressure of static explosion shockwave, quasi-static overpressure and structural strain) are obtained. On this basis, a simplified method and design requirements for the explosion source, cabin structure, equipment and mannequins are put forward.

  Results  Three failure modes, i.e. partial petal crevasse(Ⅰ), boundary shear fracture(Ⅱ) and large deformation of grillage structure(Ⅲ), and their criteria are obtained. However, the criteria for failure mode Ⅰ are given:the explosion distance is one fourth less than the width of the plate, and the explosion energy is greater than the plastic deformation energy arising from the bending.

  Conclusions  This paper expands research into the failure modes of rectangular grillage structures under the effect of explosion deformation, enabling it to provide valuable references for the anti-explosion evaluation and protection design of ships.