ANSYS Structural Mechanics UK/staticassets/FEA... · ANSYS Structural Mechanics Mark Leddin ANSYS...
Transcript of ANSYS Structural Mechanics UK/staticassets/FEA... · ANSYS Structural Mechanics Mark Leddin ANSYS...
© 2010 ANSYS, Inc. All rights reserved. 1 ANSYS, Inc. Proprietary© 2010 ANSYS, Inc. All rights reserved. 1 ANSYS, Inc. Proprietary
ANSYS Structural Mechanics
Mark Leddin
ANSYS UK
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The Cost of Failure!
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Agenda
• Products on offer
– Implicit
– Explicit
– Add-ons• Composites
• Fatigue
• Technology
– Elements
– Materials
– Contact
– Recent solver enhancements
– ANSYS Dynamics
– Explicit Dynamics
• Workbench
– Process flow and automation
© 2010 ANSYS, Inc. All rights reserved. 4 ANSYS, Inc. Proprietary
ANSYS Mechanical FEA Suite
• Founded in 1970, ANSYS have been
developing generic Mechanical FEA software
for 40 years
• Originally developed for the nuclear industry,
quality was paramount in its design, now
in accordance with ISO quality controls
• ANSYS FEA has the broadest range of
capabilities in the market-place, with
technologies for:
– Linear & Nonlinear (geometric/material)
analyses
– Static, frequency-domain & time-domain
– 0-D to 3-D elements
– Isotropic, anistropic, layered materials
– ....
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ANSYS Mechanical Solutions
ANSYS Mechanical solutions articulates the best in class CAE
products and technology for structural, thermal, acoustics
and coupled physics analysis that offers a unique class of
integrated simulation solution for the entire product
development process …
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Product Offering/Target Users
• Built upon robust technology offers a range of products with a clear upgrade path from designers to
analyst.
ANSYS
Professional
PlanDrafting
CAD
Concept
Simulation
Virtual
Prototyping
Advanced
AnalysisEvaluate Production
ANSYS
DesignSpace
ANSYS
Structural
ANSYS
Mechanical
ANSYS
DesignSpace
Mid-RangeFront End High-End
ANSYS
Professional
ANSYS
Structural
ANSYS
Mechanical
ANSYS
Multiphysics
Functi
onality
/Pri
ce
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Product/Technology Description
ANSYS
DesignSpace
ANSYS
Structural
ANSYS
Professional NLT
ANSYS
Mechanical
Linear Structural
Steady State Thermal
Linear Structural
Steady State Thermal
Transient Thermal
Linear Dynamics
Linear Structural
Non-Linear Structural
Linear Dynamics
Nonlinear Dynamics
Linear Structural
Non-Linear Structural
Linear Dynamics
Nonlinear Dynamics
Steady State Thermal
Transient Thermal
Acoustics
Direct Coupled
Solver Technology
ANSYS
Professional NLS
Linear Structural
Steady State Thermal
Nonlinear Structural
Linear Dynamics
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Explicit Analysis
• ANSYS Explicit Dynamics Products:o ANSYS Explicit STR, ANSYS LS-DYNA, ANSYS AUTODYN
• Short duration localized phenomena• Transient dynamic wave propagation
o Gases, Liquids, Solids and their Interaction (FSI)• Nonlinear
o Material behavioro Structural behavioro Contact/Interaction
• Extreme loadings• Extreme deformations
o Large strains & strain rateso Material failure
Courtesy of Sandia National Laboratory
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ANSYS nCode DesignLife
• Premier fatigue analysis tool
• Analyze implications of repeated,
fluctuating, and rapidly applied loads,
which can result in failure or damage• Stress-Life (single, multi-curve, Haigh diagrams)
• Strain-Life (automated multi-axial corrections)
• Multi-axial safety factor (Dang Van)
• Seam welds and spot welds
• High temperature fatigue
• Vibration fatigue (shaker simulation)
• Multiple runs in a single analysis
• Complete duty cycles
• Multi-processor enabled for fast results
• Use Python for proprietary or custom methods
© 2010 ANSYS, Inc. All rights reserved. 11 ANSYS, Inc. Proprietary
ANSYS Composite Prep/Post
• Composite materials
– Light
– Strong
– Good corrosion resistance
• Complex manufacturing
– Multiple materials
– Multiple directions
Composite examples
Simple geometry's easy to handle
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ANSYS Composite Prep/Post
• Take loaded FE model from
ANSYS Mechanical
• Build model as manufactured
– Ply by ply manufacture
– Draping
– Section cuts
• Use proven ANSYS FEA solver
• Post process using composite
criteria
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ANSYS Composite Prep/Post
• Composite specific
post processing
– Layer by layer
– User selected failure
mechanisms
– User defined failure
criteria
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Geometry is imported in ANSYS Workbench. Loads and
boundary conditions are defined on the geometry.
ACP & FiberSim
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Agenda
• Products on offer
– Implicit
– Explicit
– Add-ons• Composites
• Fatigue
• Technology
– Elements
– Materials
– Contact
– Recent solver enhancements
– ANSYS Dynamics
– Explicit Dynamics
• Workbench
– Process flow and automation
© 2010 ANSYS, Inc. All rights reserved. 19 ANSYS, Inc. Proprietary
Elements Technology
Solid Elements
2D Quad/Tri
3D – Hexa/Tetra/Wedge/Pyramid
Layered Solids
Solid Shell
Beam Elements
Multi material beam analysis
Beam Cross Section Definition
Shell Elements
Lower/Higher Order
Layered Shells
Special Elements
Rebars/Reinforcements
Links/Pipes/Springs
Cohesive Zone
User Elements
Gaskets
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Materials Modeling
Material Models
Isotropic/Orthotropic Elasticity
Hyperelasticity
Plasticity
Viscoelasticity
Viscoplasticity
Creep
Other Models
Cast Iron Plasticity
Drucker-Prager
Shape Memory Alloy
USERMAT
Gasket Material
Concrete
Gurson DamageGasket Material
Hyperelastic Material
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Material Models
Rate Dependent Chaboche Plasticity Model
• Based on Chaboche nonlinear kinematic
hardening model
• Plastic strain rate-dependent effects
• Captures cyclic hardening & softening
Applications/Benefits
• Applicable for turbine and engine design
• Simulation of ratcheting and shakedown
• Strain rate dependent applications, e.g.
impact simulations -3.E+08
-2.E+08
-1.E+08
0.E+00
1.E+08
2.E+08
3.E+08
-0.015 -0.010 -0.005 0.000 0.005 0.010 0.015
Str
es
sDisplacement
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Material Models
• Response Function Model
• Chaboche Kinematic Hardening
• Anand Plasticity Model
• Gasket Material Model
• Temperature Dependency for
– BISO, BKIN,
– All Hyperelastic models
including Gent, Blatz-Ko, Arruda
Boyce
• Enhanced - Anisotropic Elasticity
UI to check for input error
Curve fitting support for
temperature dependent
Gasket
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Contact Analysis
• Node-Node; Node-Surface; Surface-Surface; Line-Line; Line-Surface
• Small and Large Sliding
• Lower and Higher order elements
• Pure Penalty; Augmented Lagrange; Pure Lagrange; MPC contact
• Semi-Automatic Contact Stiffness Update
• Multiphysics Contact; Rigid Contact
• Friction Sliding (Small/Large Deformation)
• Shell/Beam Thickness Effects
• Contact Manager Wizard
• Automatic Assembly Contact
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Contact Modeling
Fluid Pressure Penetration Support
Model fluid penetrating 2 contact surfaces
2D/3D surface-to-surface contact pair
Small and large sliding contact
Rigid-flexible and flexible-flexible contact
Usage
Pressure applied normal to contact & target
elements
Can be cut off when contact is restored or
contact pressure is larger than the fluid
pressure
Applications
Post-Leakage simulation
Sealing performance evaluation
Fluid pressure is applied
Fluid pressure is Not applied
Seals
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Debonding and Contact
• Used with 2D and 3D contact elements
• Supports augmented Lagr., penalty methods
• Debonding can be used to model failure modes
– Mode I (normal) , Mode II (tangential) or Mixed mode
(mode I and mode II)
– Debonding is available for bonded contact
• Specified through TB,CZM
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Fracture Mechanics
Enhancements to J-integral Calculations
Thermal strain is automatically included
in the J-Integral calculation
Surface pressure load on element
surfaces or edges is automatically
included in the J-Integral calculation
Benefits/Applications
Provide accurate estimation of J-Integral
when there are thermal strains and
surface pressures on crack faces
Structural integrity assessments
Nuclear reactor safety analysis
Spot Weld
Failure Analysis
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Example
Turbine Blade Crack Analysis
PRCINT prints calculated
J-Integral values to
Solution Information
Window
Penny Crack
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SNODE Solver for Modal Analysis
• Splits FE matrix in to smaller pieces –
SuperNodes
• Solves reduced eigenvalue problem
• Transforms eigenvectors back to the
original FE domain
Benefits
• Ideal for > 3 mil. DOFs , >500 modes
• Non-iterative – i.e. will not fail to converge
• Does not miss modes
Applications
• Beam, shell or thin geometries
• Automotive, aerospace
• High frequency response analysis, etc.
Advances in Solver Technology
0
20000
40000
60000
80000
100 1000 4000 8000
CP
U T
ime
Number of Modes
Block Lanczos
Supernode
Single Xeon 3.4 GHz processor
►17+ hours reduced to ~1 hour
►7 TB of I/O reduced to <300 GB
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Cyclic Symmetry Support
• Static and Modal Analysis
Support
• Thermal-Stress Support
• Smart Boundary Constraints
Manager
• Expansion of the sector
• Travelling Wave animation
• Support Pre-stress Modal
Cyclic Symmetry
• Peak Holds Results
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ANSYS Dynamics
Nonlinear Transient
DynamicsModal Harmonic Response
Modal Superposition
Linear Transient
DynamicSpectrum Harmonic Response
Response Spectrum Random Vibration
Rigid DynamicsFlexible Dynamics
(Implicit & Explicit)
ANSYS Dynamics
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Common Uses
• Commonly used for
– Airborne electronics
– Acoustic loading of Airframe parts
– Jitter in alignment of optical equipment
– Relative deformation in large mirrors
Random Vibration Analysis
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Power Spectral Density
• The Power Spectral Density is the mean
square value of the excitation for a unit
frequency band.
– The area under a PSD curve is
the variance of the response
(square of the standard
deviation).
– The units used in PSD are
mean square/Hz (e.g. an
acceleration PSD will have
units of G2/Hz).
– The quantity represented by
PSD may be displacement,
velocity, acceleration, force, or
pressure.Random Vibration curve by MIL-STD-202
Random Vibration Analysis
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• Rigid Dynamics– Determination of Motion and Forces
• Assume no flexibility to parts• Large rotations and displacements• Full view of mechanism motions• Automated redundancy analysis
– Fast solves• Flexible Dynamics
– Determination of Motion, Forces, Deformations and Stresses• Nonlinear anything allowed (contact,
geometric, material)• Selectively define flexible bodies• High fidelity models
– Longer solves, but more details– CMS available to speed-up solves
• Control System Modeling– Links and co-simulation between
Simplorer and structural dynamics solutions
Rigid vs. Flexible Dynamics
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Key Benefits of ANSYS Rigid Body
Dynamics
• Extremely Fast Solution
– Often measured in seconds for even
complex assemblies
• Efficient Model Setup Tools
– Configuration tool for manipulation of
assembly and identifying problems
– Ease of conversion from all-rigid to combined
rigid-flexible model
• Single integrated modeling environment
• Iterative "what if" simulations
– Parameterization allows rapid manual
optimization due to the very low CPU
requirements of an all rigid dynamics solution
• Wide industry applicability (automotive,
aerospace, robotics, biomedical ....)
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Features
• Access within ANSYS Workbench
• Familiar user interface
• ANSYS AUTODYN solver
Benefits
• WB Native, data sharing with other
WB applications
• Short learning curve for WB users,
easiest explicit to learn
• Mature element/solver technology
Applications
• Impact events
• Highly nonlinear events
• Very short transients
ANSYS Explicit
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Graphical User Interface
- Data Sharing between ANSYS systems
Persistent Data Sharing between ANSYS systems
Operational Load Case (Static)
Ultimate Load Case (Explicit)
Natural Frequencies (Modal)
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Connections
- Sliding Contact
Features
• Trajectory contact method
• Nodes and faces are tracked during
computational cycle
• Penalty and Energy Conserving
• Optional Definition of Contact Regions
for Efficiency
• Body Self Contact
• Edge-on-Edge Contact
• Frictionless/Frictional, Static/Dynamic
• Eroding Contact
Benefits
• Simple/Automated definition
• Ease of use Workbench is famous forCourtesy FhG-EMI,
Germany
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Features
Face groups/parts to be bonded
Normal/shear stress failure criterion:
Benefits
Connect dissimilar meshes
Model conditional connections
Model connection failures
Applications
Non-congruent meshes
Laminated components
Glue joints
Connections
- Breakable Bonded Contact
1
expexp
s
s
s
n
n
n
SS
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Impact and Ballistic Protection
Normal and oblique HVI impact validations
For space vehicle shielding systems
• Example Application
– Hypervelocity Impact
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Agenda
• Products on offer
– Implicit
– Explicit
– Add-ons• Composites
• Fatigue
• Technology
– Elements
– Materials
– Contact
– Recent solver enhancements
– ANSYS Dynamics
– Explicit Dynamics
• Workbench
– Process flow and automation
© 2010 ANSYS, Inc. All rights reserved. 46 ANSYS, Inc. Proprietary
ANSYS Workbench
• Being part of the ANSYS Workbench
infrastructure opens up several
enhancements in overall process for the
structural mechanics users
– Geometry
– Meshing
– Post-processing
– Reporting
– Process scripting & chaining
– Automatic Project updates
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ANSYS Workbench
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ANSYS Structural Mechanics
• ANSYS Structural analysis
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DesignXplorer
• Start with a workbench defined process
– Use parameters in:
• CAD
• DesignModeler
• SpaceClaim
• Engineering data
• Preprocessor
• Postprocessor
• Derived parameters
– Define design envelope• Parameter limits
• Descrete/continuous
– Define goal• Near target
• Min/Max
• Trade offs
© 2010 ANSYS, Inc. All rights reserved. 54 ANSYS, Inc. Proprietary
DesignXplorer
• DOE
– Select DOE type
– Custom + Sampling (OSF)
• Candidate designs
• Response surface
• Six Sigma analysis
– Manufacturing best/worst case
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Summary
• 20 years ago
– 1 geometry > meshed by hand > 1 set of material properties >
worst case loading > evaluate stresses > assign safety factor
make design decision
• Today
– Import CAD geometry > auto mesh > ±3 variation in material
properties > ±3 variation in load values > durability assessment
make design decision