Blast & Impact Loading & Response of Structures
Frangible walls are generally employed to mitigate blast effects in weapon silos, weapon manufacturing units and weapon testing structures etc.., In case of an internal explosion, the weak frangible elements fails, thereby releasing the pressure into the external atmosphere and protecting the adjacent facilities. This paper focus on the numerical simulation of blast mitigation phenomenon involving frangible walls. Numerical FEA software LS-DYNA is used for the simulation. A 3D MMALE approach is used with surrounding walls being modeled as Lagrangian elements. Initially simulation is carried for an internal explosion with no vent, followed by, one solid wall as frangible element. Failure criteria is imposed for the weaker strength frangible elements. Gauge points are placed at various locations and the results are evaluated and compared against codal provisions. Measurement of reflected pressure in different positions confirms ‘pressure reduction’ by the usage of frangible elements.
Further advanced numerical simulations are carried out for frangible walls as brick wall with mortar joints. Different contact types have been worked on to arrive at stable solution. Results of the numerical simulations confirms the Blast effects get mitigated upto a range of 15 to 20 percent by the usage of frangible elements.