Analytical and Numerical Studies of Hemispherical Closure Shell Subjected to Blast Loading

Explosion is a very complex phenomenon creating blast waves, leading to very large-scale destruction of the surrounding objects/structures, and living things. To protect the lives of people, critical ammunition and to handle NBC warfare situations, hardened structures/shelter homes are constructed. Such building structures require a particular type of component, called Blast Valve, which fulfils the requirement of ventilation in the meantime as well as shuts off the airflow passage when it detects blast overpressure above safe limits. The closure shell is one of the important components of the Blast Valve used to shut off the airflow passage in the event of an explosion outside the building structure. In this paper, analytical analysis for modelling impulse on the closure shell of the Blast Valve has been carried out, and validation has been done by numerical analysis using ANSYS Autodyn. The source of the blast wave is an explosion created from 22 kg of TNT, which is exploded at 5.3 m from the structure. The geometry of the closure shell of the Blast Valve is hemispherical with uniform thickness. Front-wall loading type model is used for modelling impact due to the explosion. The material selected for the closure shell is SS304 which is considered due to its good mechanical properties.