IMPACT BLAST. Diagnosis and design of civil engineering structures under sever accidental loading - Hard low velocity impact and blast

Diagnosis and design of civil engineering structures under sever accidental loading - Hard low velocity impact and blast SUMMARY IMPACT Drop of a 14t steel canister on an RC storage silo Description of the canister and the silo Modelling assumption (mesh, MCL, BC, ) Results and analyses BLAST Design of the structure of an experimental facility Description of the structure Design process and modelling strategy Dr. Shahrokh GHAVAMIAN NECS, 196 rue Houdan 92330 SCEAUX France sg@necs.fr EHTC 2009-103.11.2009 1 www.necs.eu

IMPACT Case study #1 Canister RC storage silo 4HA10 z= 30 mm HA10, e= 200 mm z= 300 mm 4HA14 z= 300 mm EHTC 2009-203.11.2009 2 www.necs.eu

IMPACT Case study #1 Modelling assumptions Detailed modelling of impacted area Elements included in the model : -Ground - Steel beams - Concrete infill -RC pipes - RC top and bottom slabs - Steel and concrete covers - Container (steel + wood) EHTC 2009-303.11.2009 3 www.necs.eu

IMPACT Case study #1 Material constitutive models Concrete & RC: ML24 (damage, elastoplastic theory) Steel: ML27 (plasticity) Wood: ML27 (plasticity) Soil: ML1 (linear elastic) EHTC 2009-703.11.2009 7 www.necs.eu

IMPACT Case study #1 Calculation results Energy: Balance and evolution IE+KE+HE+CE IE KE CE HE EHTC 2009-803.11.2009 8 www.necs.eu

IMPACT Case study #1 Calculation results Effort developed in the wooden dashpot (stress) EHTC 2009-903.11.2009 9 www.necs.eu

IMPACT Case study #1 Calculation results Deflection of concrete slab and infill (strain) EHTC 2009-1003.11.2009 10 www.necs.eu

IMPACT Case study #1 Calculation results Effort transmitted to critical elements at foundation level (stress) EHTC 2009-1103.11.2009 11 www.necs.eu

IMPACT Case study #1 Calculation results Effort transmitted to critical elements at foundation level + Their deflection (vertical displacement) EHTC 2009-1203.11.2009 12 www.necs.eu

IMPACT Case study #1 Preliminary verifications of models (benchmarking) Concrete material constitutive model: First calculations indicated concrete stress values above maximum limits provided as input data Following investigations, an opening was found in the load surface of the material model. Consecutively the constitutive model ML24 was improved by Altair. EHTC 2009-1303.11.2009 13 www.necs.eu

BLAST Case study #2 Presentation of the structure RC structure One large, and several small, openings Overhead crane Gravity, wind, and internal static pressure Dynamic 3 to 50 kg TNT eq explosions Top view EHTC 2009-1403.11.2009 14 www.necs.eu

BLAST Case study #2 Requirements in terms of performance No collapse in case of an accident (50 kg TNT), severe damage is tolerated : Cracking of concrete Yielding of rebars Large plastic hinge rotations No damage of the structure due to every day tests (< 3 kg TNT) No cracking of concrete EHTC 2009-1503.11.2009 15 www.necs.eu

BLAST Case study #2 Modelling process Model preparation 3D CAD model Autocad Meshing (structure, soil, air, TNT) Salomé Verification and computation RADIOSS mode preparation Python scripts Verification analysis RADIOSS Dynamic analysis RADIOSS Verification analysis Code_Aster Static analysis Code_Aster Result processing and design Load case combinations Python scripts Steel Reinforcement calculation BAEL / UFC 3-340 EHTC 2009-1603.11.2009 16 www.necs.eu

BLAST Case study #2 2D CAD drawings 3D CAD model Meshing T=150 ms Pression (GPa) Reinforcement Deflection Overpressure surrounding the installation EHTC 2009-1703.11.2009 17 www.necs.eu

BLAST Case study #2 3D mesh Air limit Roof slab Walls TNT charge Air Air Ground Foundation slab EHTC 2009-1803.11.2009 18 www.necs.eu

BLAST Case study #2 3D mesh Air TNT Ground EHTC 2009-1903.11.2009 19 www.necs.eu

BLAST Case study #2 TNT load adjustment Free field explosion Analytical solution vs Simulation results Pressure (bars) Distance (meters) EHTC 2009-2003.11.2009 20 www.necs.eu

Blast pressure propagation Overpressure / structure interaction Deflection Stress in structure Reaction forces BLAST Case study #2 Results EHTC 2009-2103.11.2009 21 www.necs.eu

Concrete steel reinforcement BLAST Case study #2 Results Wall VX1 PORTE1 Voile VY1 Voile VX2 PORTE4 Nord PORTE2 PORTE3 PORTE5 Voile VX1 PORTEBAT PORTE6 Voile VY2 Horizontal rebar ratio (cm²/m) EHTC 2009-2203.11.2009 22 www.necs.eu

BLAST Case study #2 Design drawings EHTC 2009-2303.11.2009 23 www.necs.eu

CONCLUSIONS With RADIOSS we manage to perform our studies where implicit algorithms are not suitable Need to improve several points to gain the trust of more clients: A more suitable material model for concrete ( famous, extensively validated, with indication to identify input parameters) Improve and demonstrate the quality of our studies (benchmarking) Perform developments to improve the efficiency of our process (model preparation and result processing) EHTC 2009-2403.11.2009 24 www.necs.eu