industry sector rtd thematic area date aerospace / … autodyn explicit multi-solver and coupled...

FENET THEMATIC NETWORKCOMPETITIVE AND SUSTAINABLE GROWTH(GROWTH) PROGRAMME

Industry Sector RTD Thematic Area DateAerospace / Marine & Offshore Multi Physics and Analysis 27-28/02/2003

Fluid-Structure Interaction Methods in Practice:Numercial Analysis of Extreme Loads

Colin J. HayhurstCentury Dynamicshttp://[email protected]

Summary – Fluid-structure coupling approaches used for extreme loads. Efficient techniques used in commercial codes for the aerospace, marine and offshore sectors


Software Products

AUTODYN

Explicit multi-solver and coupled non-linear dynamic analysis code

AutoReaGas

CFD code for gas explosions and blast effects analysis

ASAS

General Purpose Linear and Nonlinear FE Suite

AQWA

Linear and Nonlinear Hydrodynamic Analysis Suite


AUTODYN

Non linear transient dynamics

Explicit

Multi-solver

Solver coupling

Contact

ALE coupling

Meshfree capability with coupling

“Euler-Lagrange” coupling


AUTODYN-2D & 3D

Owned and Developed by Century Dynamics since 1985

Integrated Pre-processor, Solvers and Post-processor

Numerical programs for Transient Non-Linear Dynamics Analysis

Finite Element, Finite Volume and Meshfree Solvers

Material ModelsSolids, Liquids, Gases and Multiphase

Metals, Plastics, Composites, Glass, Ceramic, Explosives, Soil, Concrete, Water

Equations of State

Constitutive Models

Designed from inception for Fluid-Structure Interaction


AutoReaGasGas explosions

Navier-Stokes solver

Laminar & Turbulent Combustion

Complex geometries

Feedback of combustion, expansion and turbulent flow

combustion expansion

flow structure


AutoReaGas

Complex geometries

Finite Volume, rectilinear mesh

Rigid objects and panels with blow-out

Subgrid representation of small objects

Gas cloud and ignition point input


AutoReaGas Applications

GasExplosionFull-Scale

Tests

Gas ExplosionOn Offshore

Platform

Chemical Plant

3D ModelGeometry

of an FPSOfrom PDMS


Gas Explosions - Coupling

Two way simple rigid body coupling in AutoReaGasCompute pressure difference on a panelBlow-out panel at critical pressureOpen flow area based on panel inertia

One way couplingAutoReaGas Gas Explosion Results Transferred to AUTODYN or ASAS

Two way couplingRemap AutoReaGas gas state into AUTODYNRun coupled Fluid-Structure coupled simulation in AUTODYN


Blast-Structure Interaction


AQWA

Linear and Nonlinear Hydrodynamic Analysis Suite

Potential flow solver

3D diffraction/radiation analysis

Frequency domain analysis

Non-linear time-history simulation

Analysis of coupled line dynamics and riser systems


ASASFinite element based structural analysis suite

Linear and nonlinear

Owned and developed by Century Dynamics since 2001

Developed since 1971 by WS Atkins

Continuous and frame structures

Frame, panel and concrete structure code checks

Wave-structure interaction for regular and irregular wavesCourtesy Exxon Mobil


AQWA-ASAS CouplingCalculation and transfer of hydrodynamic loads from AQWA to ASAS

AQWA-LINE

ModelASAS

Model

Motions & Pressures

AQWA

WAVE


Wave Loading ASASFirst ever real on-bottom simulation. Following launch, before fully piledWave applied as transient moving distributed loadingNon-linear springs and dampers to simulate the mudmat and skirtTransient time analysisRegular extreme 100 year wave

Courtesy Teknisk Data AS


Numerical Methods

MeshfreeLagrange Euler


AUTODYN SolversSolvers use Finite Volume, Finite Element & Meshfree

Spatial Discretizations

Time Integration is Explicit

Solid ”Lagrange” Single point integration “brick”Shell/MembraneBeam/Truss/Spring/DamperSPH Meshfree Lagrangian particlesEuler Multi-material 1st orderEuler-FCT Single-fluid 2nd orderEuler-Godunov Multi-material 2nd orderALE Lagrange with Remeshing


AUTODYN - Coupling

All two way couplingPossible ways to model fluid-structure coupling

Multi-material Euler VOF schemeContact between Lagrangian SurfacesJoined Lagrangian InterfaceALE interface to LagrangeMeshfree contact to Lagrange or ALEEuler coupling to Lagrange

No scheme is the best, one needs a choiceExamples then Euler-Lagrange coupling method


Hydraulic RamExploding projectile impacts compositewingboxWater simulates fuel in simulations and testsProgressive damage model for composite

Fully Lagrangian analysis using automated contactSeverely distorted elements removed


Shaped ChargeCutting charge using hypervelocity jetJet softens and can meltMetallic casingHigh explosive chargeAsymmetric detonation

Solved using 3D EulerMulti-material flow and deformationVolume of Fluid (VOF)No mesh generation but need to calculate initial volume fractions


Hypervelocity ImpactSpace debris impact velocities from 3 to 20km/sAluminium melts at 6km/s and vaporises around 10km/s

Simulation uses SPH in central highly deforming regionsSPH is joined to Lagrange which models outer regions and boundaries

Development of ISS shieldsAssessment of damage on satellites, HST, XMM


HVI Validation

AUTODYN-3D Simulation


Euler-Lagrange Coupling

Euler exerts pressure on Lagrange “structure”Lagrange acts as flow boundary for EulerAs Lagrange moves new Euler cells become uncoveredSo-called “CEL” of “Cut-cell” type techniques

Euler

Lagrange


Euler-Lagrange Coupling

Local pressures integrated over interface segmentPartially covered cells merged - “Blending”Mesh sizes should not differ greatly

Subcycling can aid speedKey is speed of geometrical searchesNo Euler “fluid” mesh generation P2

P1


Launcher Stage Separation


Blast/Structure Interaction

Explosion inside brick buildingSafety distances

Euler-Lagrange Coupling allows automated FSI with large motion


Blast/Structure InteractionExplosion close to a reinforced

concrete panelAutomated FSI with large motion

and break-up/fracture of panel


Thank youQuestions ?

Fluid-Structure Interaction Methods in Practice:Numercial Analysis of Extreme Loads

Colin J. Hayhurst

http://[email protected]

industry sector rtd thematic area date aerospace / … autodyn explicit multi-solver and coupled...

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