Blast Simulation of Vault Door As Per EN 1143-1' Godrej Security Solution Division Godrej & Boyce Mfg. Co. Ltd., Mumbai Satish Ramavat Devidas Thorat Prashant C. Date 25 July, 2016
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Product Introduction: Frame Hinge Door Leaf Locking Bolts here 3
Introduction: Frame Construction of Vault door: It consists of frame, door leaf and mechanism for locking. Frame and door leaf are filled with concrete barrier to provide the protection against any attack. Frame is used to fix vault door with wall of vault room. Intended function: Vault door is designed to protect against the burglary attack and also provide the access to vault room. Hinge Door Leaf Locking Bolts here 4
Locking Mechanism: It consists of locking bolts, handle, glass, and relockers. here 5
Blast Simulation of Vault door: Need for Simulation: The vault door was to be tested against explosion attack as per EN 1143-1, hence there is a need to evaluate the performance of door against specified explosive attack before actual test. To optimise the door design and thus eliminate the testing iterations which are very expensive. Scope for Simulation: Analyse the effect of detonation of explosive placed in gap between frame and door. Visualization of blast wave propagation and its effect on different parts. Identify the forces and stresses at different locations. Effect of blast on mechanism parts like locking bolts, linkages and etc. here 6
FEM Details Hexahedral elements used for air and explosive modelling. Shell elements used for door and frame. Concrete metal rebar s are modelled as beam elements. Type 18 contacts used between Air and explosive. here 7
FE Modeling: Detonation Point Air Domain Frame here 8 Door Leaf
Material details: Material : IS 2062 E250 Gr.B0 Card image: M2_plas_johns_Zeril Yield Stress ( y) (a) Tensile Strength :250 MPa :410 MPa Elongation at Fracture (EPS_max) :23 % Modulus of Elasticity (E) :210 GPa Mass Density ( ) :7810 kg/m 3 Poisson s Ratio ( ) :0.29 Material : Concrete Card image: M24_Conc Compressive strength (fc) :150 MPa Density ( ) :2900 Kg/m 3 Flexure strength :12 Mpa EPS (Max) : 0.5% here 9
Boundary Condition: The frame (left picture) are fixed in all DOFs to replicate the test conditions (right picture). here 10
Explosive details: PETN- 285 g TNT Explosive : Mass density (ρ) : 1500 Kg/m 3 Detonation velocity (v) : 7000 m/s Chapman-Jouget pressure : 16 GPa Internal energy density (E 0 ) : 10.1 GPa Material constants of JWL EQS for TNT : ω : 0.25 A : 617 GPa B : 16.926 GPa R 1 : 4.4 R 2 : 1.1 Door Leaf here 11 Frame
Challenges faced: Concrete modelling We modelled the steel bar reinforcement as beam elements to get realistic result and study its behaviour. Modelling of explosive into the gaps Since it is a small gap in Z shapes couple of iterations were involved to get convergence Contacts and interface Adjusting contact stiffness to model the interface behaviour here 12
Results: here 13
Results: here 14
Results: here 15
Results & Discussion: Frame and door damaged only in area near to explosive, rest area was considerably intact, same was also observed during actual test. Maximum force is observed in the locking bolt which falls into blast wave path. In actual test two locking bolts (in centre) are dislocated. Due to induced force or vibration toughened glass has broken as desired. Actual test results are very much similar to simulation results. here 16
Benefits Summary: Analysis helps to optimise the door design before actual test, this reduces the cost by eliminating iterative testing's. Reduced development cycle time and cost and time to market here 17
Conclusion: This study has shown that the predictive capability for blast wave propagation and its effect on door design is quite good with Radioss non-linear explicit analysis. In addition, Altair provided the scope for iteration with every design change to ensure the intended performance. With such good correlation between simulation and actual test results, testing laboratory also exploring the option of evaluating the design on the basis of simulation results only rather than going for actual test in each case. here 18
Acknowledgments: We would like to acknowledge our company M/s. Godrej and Boyce Mfg. Co. Ltd. Security Solutions Division and Altair s Technical support Mr. Swasthik Bangera Mr. Prashant Kulkarni Mr. Vasantha Kumar here 19
THANK YOU here 20