ANSYS Explicit Dynamics R15.0 New Features and Enhancements
Norman Robertson Lead Product Manager
[email protected]
ANSYS Explicit Dynamics R15.0 - Summary of New Features and Enhancements •
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High Performance Computing (HPC) * (HPC) * – Parallel Trajectory Contact (TC) Enhanced Connections * Connections * – Spring/Damper Exposure Implicit-Explicit Implicit-Explicit Enhancement * Enhancement * – Pressure Initialization Other Enhancements * Enhancements * – Meshing Enhancements – New “Go To” Options – Enhanced Crushable Foam Support – Double Precision ANSYS LS-DYNA – ANSYS Workbench LS-DYNA
* Capabilities described
cover both ANSYS Explicit STR and ANSYS Autodyn (where applicable)
High Performance Computing (HPC) •
General release of Parallel Trajectory Contact (TC) – Concludes a major development over a few releases, to deliver Trajectory Contact (TC) in parallel simulations •
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TC with/without erosion TC available with all Lagrange/FE solvers, except SPH or (old) “Structured FE” solvers [SPH support planned for future]
– Parallel now available for Explicit Dynamics Analysis System (working with ANSYS HPC solutions)
– Extends existing parallel (HPC) capabilities already available with the Autodyn Component System (via Gap/Proximity Contact) •
Further Parallel Support Summary – Euler-Lagrange Coupling (FSI) now in Explicit Dynamics Analysis System – Bonds (breakable & non-breakable) – Boundary Conditions (all EXCEPT Analytical Blast) – Spotwelds (breakable & non-breakable) [breakable not in Preview 3] – Remote points and Remote displacements – Shell thickness (specifically shell thickness > zero)
HPC Performance - Performance Examples (1) •
Many performance tests have been conducted – 4 examples shown here highlighting the range of latest parallel capabilities – Note speedup is dependent on a number of model factors including model size, solvers & coupling, result edits, PC and/or CPU configuration
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Example 1: Test Vessel Drop – 812,468 Elements (ANP tetrahedra, Hexahedra & Shells)
Number of Cores/CPUs Solver Time (minutes) Speedup Efficiency (%)
1 42.37 1
2 21.06 2.01 100.6%
4 12.21 3.47 86.8%
– Bonds & TC (no Erosion) Vessel Drop Speedup 8 6 4 2 0 1
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8 6.62 6.4 80.0%
HPC Performance - Performance Examples (2-3) •
Example 2: Pull Test Failure – NBS Tetrahedral elements – Limited Erosion & TC
Pull Test Speedup 6 5 4
Number of Cores/CPUs Run Time (minutes) Speedup Efficiency (%) •
1 291.30 1
2 174.68 1.67 83.5%
4 91.36 3.19 79.7%
8 52.77 5.52 69.0%
3 2 1 0 1
Example 3: Long Rod Penetration – 680,000 Elements (mostly Hexahedra, some ANP Tetrahedra) – Significant Erosion & TC
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4
8
Long Rod Speedup 5 4 3
Number of Cores/CPUs Solver Time (minutes) Speedup Efficiency (%)
1 490.30 1
2 211.70 2.32 115.8%
4 175.60 2.79 69.8%
8 110.00 4.46 55.7%
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1 0 1
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HPC Performance - Performance Examples (4) •
Example 4: Explosive Fragmentation – 788,000 ANP Tetrahedra & 344,000 Multi-Material Euler – Euler-Lagrange Coupled (FSI), Erosion & Bonded Contact Number of Cores/CPUs Solver Time (minutes) Speedup Efficiency (%)
1 321.60 1
2 179.80 1.79 89.5%
4 105.00 3.06 76.5%
8 83.10 3.87 48.4%
Explosive Fragmentation Speedup 5 4 3 2 1 0 •
In summary
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– Excellent speedup efficiencies observed across wide range of relatively small to large problems (typically speedups of at least 4 over 8 slaves i.e. over 50% efficiency)
Enhanced Connections - Spring/Damper Exposure •
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Spring connections definition available in Explicit Dynamics system Both Longitudinal Stiffness and Damping are supported – Example shows displacement of undamped (top) and damped (bottom) springs
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Linear and Nonlinear behaviour – Nonlinear spring definition via Tabular Input (unlimited data points)
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Preloads not supported
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Results trackers
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Limitations – Torsional springs not supported – Body-Ground springs not supported
Spring/Damper Exposure - Trackers •
You can use a spring tracker to display the following longitudinal result items from a spring in an Explicit Dynamics analysis – Elongation – Elongation is the relative displacement between the two ends of the springs. The elongation could be positive (stretching the spring) or negative (compressing the spring).
– Velocity – Velocity is the rate of stretch (or compression) of the spring. – Elastic Force – Elastic force is calculated as (Spring Stiffness * Elongation). The force acts along the length of the spring (see example graph below)
– Damping Force – Damping force is calculated as (Damping Factor * velocity) and acts to resist motion.
Spring Elastic Force
Implicit-Explicit Enhancement - Pressure Initialization •
Pressure Initialization for cases where only final deformed geometry known from the implicit analysis – As the mesh is seen as “undeformed”, there is no compression and therefore no pressure – ANSYS results database created using INISTATE file – Explicit simulation then intialized from the ANSYS results database – Typical example may be in material processing where initial implicit analysis may be run separately and before further implicit and/or explicit analyses
Other Enhancements - Meshing Enhancements •
Assembly Meshing – Combine separate previously meshed parts
Meshing Enhancements •
Parallel Meshing – For problems with multiple parts, parts can be assigned to a separate core to be meshed in parallel reducing the elapsed time required for meshing
– No HPC licenses are required
Other Enhancements •
New “Go To” options available for Explicit Dynamics analyses
– Identifies body interaction objects in the tree that are associated with selected bodies (see right) •
Enhanced Crushable Foam Support – The full stress/strain curve from Engineering Data now passed to solver for crushable foam
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Double Precision – All analyses are now in Double Precision (Single Precision no longer available)
– Double Precision will generally be more accurate whilst and only causing limited increase in CPU time and memory consumption (typically 10-30%)
ANSYS LS-DYNA •
ANSYS Workbench LS-DYNA – New User Interface for running ANSYS LS-DYNA – Joint project between ANSYS and LSTC – Provides interactive pre-processing, solve and post-processing control
– Developed using ACT in the current Workbench environment for Mechanical/Explicit Dynamics users •
Initial Release March 2013 – Initially available with R14.5 (during R15.0 development phase) – Available at no additional fee for users ANSYS LS-DYNA, ANSYS LS-DYNA PC or ANSYS LS-DYNA PrepPost (who are current on TECS)
– Is currently in addition to the Explicit Dynamics (LS-DYNA Export) System
Workbench LS-DYNA - Where to get it!
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Go to ANSYS Customer Portal – Select “Downloads” and “Extension Library” – Select “ACT Library” – Select “Workbench LS-DYNA xxx” (xxx is Version No.) – Download the extension (zip file) •
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You will be asked to accept “cleick-wrap license terms The zip file contains installation instruction and user instructions in addition to the setup and extension files
– Follow the instructions to install and use the software…
Workbench LS-DYNA - Overview
Workbench LS-DYNA - Geometry
Access to bidirectional CADInterfaces
Preparation of simulation suitable geometry
Design Modeler
Space Claim Direct Modeler
Workbench LS-DYNA - Materials
Workbench user can define materials as usual in the material-section
Choose material properties you want to include
Only materials which can be translated are accessible
The interface creates material cards depending on the chosen material model and material properties
Workbench LS-DYNA - Materials Keywords
Workbench LS-DYNA - General Model Setup
Workbench user can set up model as done in other analysis
material
contact
Interface creates corresponding cards
In general default settings are used, based on many years of experiences Additional options can be chosen
LS-DYNA user can create specific cards by choosing several options
mesh
boundaries
Workbench LS-DYNA - Analysis Settings
At least simulation time has to be chosen by user
number of CPU
Make global settings here local settings by the additional buttons
mass scaling
global hourglass control
For example: Set Mass scaling Chose number of CPU’s
output format and frequency (d3plot)
Set global Hourglass control Output frequency of d3plot Output frequency of ASCII data ...
output frequency (ASCII)
Workbench LS-DYNA - Post-Processing
General post-processing of contour data Graphic erosion not supported at R14.5 (available at R15.0)
Plot of ASCII data Time Histories
Custom Results Available via Worksheet Total and EPS only available through Worksheet
Animation of results
