Explosions occurred inside a structure due to terrorist attacks or accidental explosive incidents can cause severe damage to people and structures outside the structure. In order to reduce or predict and avoid such damage, it is necessary to accurately evaluate the characteristics of the blast pressure caused by internal explosions. However, the characteristics of the external blast pressure caused by internal explosions can only be determined for limited conditions. In this study, internal explosion tests using a steel specimen with openings on the top and sides were conducted. The effects of the position and size of the openings on the blast pressure-time profiles were examined, and the distribution of the maximum blast pressure and blast impulse were evaluated.
