UG_20090206_Vantomme

Contribution of Contribution of Royal Royal MilitaryMilitary AcademyAcademy

IWT – SBO projectFire safety in Car Parks

Kick-Off meeting06 February 2009

John VANTOMMEFermin PASCUALENA ZABALZA

Royal Military AcademyDept Civil and Materials Engineering

KoninklijkeKoninklijke MilitaireMilitaire School School -- EcoleEcole Royale Royale MilitaireMilitaireRoyal Military Academy, Brussels, BelgiumRoyal Military Academy, Brussels, Belgiumwww.rma.ac.bewww.rma.ac.be

BachelorBachelorMasterMaster

MaMa afterafter MaMa((DefenceDefencecollegecollege))

PhDPhD((withwith civil civil universitiesuniversities))

TeachingTeaching –– ScientificScientific researchresearch –– Case Case studiesstudiesin the in the fieldsfields ofof

RMAPolytechnical Faculty

Civil and Materials Engineering Dept

- Civil and mechanical engineering

- Materials and structures

- Effects of explosions on structures

Blast Blast waveswaves in air in air fromfromcondensedcondensed highhigh explosivesexplosives

Gas expansion⇓

Layer compressed air⇓

blast wave

Remark :

overexpansion⇓

reversal of flow

DETONATION

Blast wavefront parameters

Free air explosion

Defence R&D Canada – Suffield ♦ R&D pour la dēfense Canada - Suffield

Blast Trials with Fuel Air explosions (Canada)Blast Trials with Fuel Air explosions (Canada)

Defence R&D Canada – Suffield ♦ R&D pour la dēfense Canada - Suffield

TDM Blast Trials: 50 kg TBXTDM Blast Trials: 50 kg TBX

Structural Structural responseresponse to blast to blast loadload

structural structural failurefailure + + dynamicdynamic problemproblem

Resistance functionrepresents the load necessary to cause deflection

x x x x

Structural response regimes

impulsive regime td < 0,4 . T

dynamic regime 0,4 . T < td < 2 . T

quasi-static regime td > 2 . T

tdT

Research topics for parametric analysis of structural members

Loads on structural elements: - detonation or deflagration (duration of load and

change of rise time)

Structural response without /with fire- Material laws : dynamic strengthening or fire

modified behaviour- Composite action for global response of RC

elements : - modification of elastic vibration response- plastic hinge accumulation- damage mechanisms

Special feature (1)

Internal explosions in car parks- venting ⇒ pressure relief

- re – reflection of blast waves

- heat, fire

- gas pressure loading

ConfinedConfined explosion explosion = series of impulses

+ quasi-static pressure

Special feature (2)

Near field explosions- local blast overpressures > 10 bar (1000

kPa)

- transmission and reflection of shock waves in solids

(heated RC)

Near field explosions: crushing of concrete on explosion side (spalling)

Near field explosions: scabbing effect on tensile side

28 Juin 2007

Explosion testing of in fil walls made of cellular concrete blocs

Spalling effecton front side of the wall

Scabbing effect on back side of the wall

Structural stability of wall is put in danger

ScaledScaled RC RC columncolumn

specimensspecimens for for nearnear fieldfield

explosion explosion testingtesting

Assessment of structural elements

Tests on prototypes of mixed Tests on prototypes of mixed steelsteel –– concreteconcrete columnscolumns

Installation :Installation :Standing positionStanding position+ Compression + Compression effecteffectCannotCannot tumbletumble downdownAllowsAllows limitedlimitedreflectionsreflections on on groundground

SensorsSensors : : CopperCopper--crushcrush cylindercylinderStrainStrain gaugesgauges

Tests on prototypes mixed Tests on prototypes mixed steelsteel–– concreteconcrete columnscolumns

ModellingModelling of blast of blast behaviourbehaviour of RC of RC and mixed and mixed steelsteel –– concreteconcrete columnscolumns

AUTODYN version 4.2.02aAUTODYN version 4.2.02aCentury Dynamics Century Dynamics IncorporatedIncorporated

HydrocodesHydrocodes ::HYDROdynamicHYDROdynamic computer CODEScomputer CODES

2D model: SPH processor2D model: SPH processor((SmoothSmooth ParticleParticle HydrodynamicsHydrodynamics))

Numerical analysis : hydro-dynamic behaviour of materials

Experimental test and model (Autodyn) of a mixed steel – concrete column

Oklahoma-city : 2,4 Tons TNT equivalent

Failure in punching shear

Importance of enhanced connections between slabs and columns

Conclusion : RMA contribution to Conclusion : RMA contribution to IWT SBO IWT SBO FireFire projectproject

WP 1 : design for minimising fire and explosion risk: - parametric analysis of cause – consequenceWP 2.1 : parametric analysis of structural members- slab and column: structural behaviour- the combination blast – fire - gas pressure- Analytical models- Numerical models: hydrocode (impact of material

behaviour laws)WP 2.2 : Connections – punching shear- Real scale tests : fire with blast