This paper aims to reveal the influence of the afterburning effect of explosive materials in confined space explosion.

A series of TNT blast tests are performed in a confined cabin filled with two different atmospheres, air and nitrogen. The temperature, pressure-time histories and deflection of the blast-loaded steel plate are recorded. The relationship between the deformation of the target plate and the energy released by the explosive is established. On this basis, a TNT equivalent method is proposed which takes into account the afterburning effect in a confined cabin.

The pressure, temperature and dynamic response of the target plate are significantly lower in the nitrogen environment than in the air environment due to the difference in the amount of energy released by the combustion of the explosive material. Thus, the energy released by the burning of TNT explosive materials and their enhancement effects should be considered in blast load analysis.

The validity and applicability of the method are illustrated through a comparison with the existing TNT equivalent method based on quasi-static pressure.

This paper studies the coupled damage effects of a ship's structure due to the internal blast loading of a warhead.

Blast tests with cased charge data are conducted to verify the effectiveness of the coupled SPH-FEM approach, and numerical calculations are then performed on real ship compartment scale model tests to analyze the coupled fragmentation and shockwave damage effects of an explosion in a confined cabin.

The results show that the fragments caused by the detonation of the warhead will first cause local damage to the cabin structure. The shockwave will exacerbate the local damage, and blasted openings will further increase the space for the propagation and diffusion of the shockwave inside the chamber, which will in turn cause damage to the adjacent structures. The simple equivalence of the warhead to a bare charge does not give a true picture of the effect of the warhead on the ship's structure, and fragmentation plays a significant role in the detonation of the warhead.

The results of this study show that employing the coupled SPH-FEM numerical method to calculate the coupling damage effects on a ship's structure can accurately reproduce the warhead damage pattern in tests, thereby providing support for the improved assessment of the damage of naval structures under warhead detonation.