advancing the state of the art ansys mechanical
TRANSCRIPT
1 © 2017 ANSYS, Inc. July 4, 2018
Advancing The State Of The ArtANSYS Mechanical
Yongyi Zhu, PhD
Research and Development Fellow
Mechanical Business Unit
2 © 2017 ANSYS, Inc. July 4, 2018
Unparalleled HPC Scalability
3 © 2017 ANSYS, Inc. July 4, 2018
Distributed ANSYS Performance
• Unmatched performance of Distributed Solver, even at very high CPU counts
• Excellent Scalability for Harmonic Analysis
• Unprecedented Scalability with Nonlinear Contact in implicit solver
Largest Implicit FEA Model1 Billion DOF Solved!
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Scalability At Very High Core Count
•Improved scaling to 3000+ cores
Mold
PCB
Solder balls
• 16 million DOF; sparse solver• Nonlinear transient analysis• Linux cluster; each compute node contains 2 Intel Xeon Gold 6148 processors, 192GB RAM, SSD, RHEL 7.3• Intel Omnipath interconnect
• Model courtesy of MicroConsult Engineering GmbH• Cluster data provided by Intel via the Endeavor cluster
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DMP Scaling Comparison
R18.1
R18.2
R19.0
3000+
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•Faster performance for Block Lanczos eigensolver
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DMP Performance
R17.0
R18.0
R19.0
R19.2
Faster performance in R19.2
Distributed ANSYS Enhancements
• 9.7 million DOF; LANB eigensolver• Modal anaysis involving SOLID187 elements• Linux cluster; each compute node contains 2 Intel Xeon Gold 6148 processors, 384 GB RAM, SSD, CentOS 7.3, Mellanox EDR Infiniband
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New Scaling Performance Achieved for Nonlinear Contact
•R18.2: Small Sliding Contact along with HPC Enables Tremendous Speed Boost
• 3.8 million DOF; sparse solver• Static Analysis: Nonlinear contact, plasticity and gasket elements• Linux cluster; each compute node contains 2 Intel Xeon E5-2695v3 processors, 256GB RAM, SSD, SLES 11.3• Mellanox FDR Infiniband
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DMP Scaling Comparison
R17.2
R18.1
R18.2
R18.2 - Split - Trim
FKN for gasket
Small sliding
R20.0 DMP Contact2x speedup
3x speedup
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CONTACT
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Beam Contact – 18.1
Drill String Insertion Simulation
Cable Wire Twist Test Simulation
Tennis Racquet String Test
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Case1: Solid Tube – Solid CoilsSOLID186 - SOLID186
Case2: Solid Tube - Beam CoilsSOLID186 - BEAM189
Case3: Beam Tube - Beam CoilsPIPE289 - BEAM189
SMP with NP=2 Case1 Case2 Case3
Wall time (s) 29300 6907 1077
Cum. iteration 481 287 159
Max Usum 2.1165 2.11679 2.11645
Max Seqv 1991.56 1550.78 1564.72
Five-filar Metal Coil Inside A Polymer Tube Model
27X
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Contact Surface WearBorgwarner: Predicting Wear on Turbocharger Component ANSYS Advantage Magazine Volume X Issue 3 2016
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Small Sliding ContactConcept: • Small-sliding contact assumes that relatively small
sliding motion (<20% contact length) occurs between the contact and target surface, but arbitrary rotations of contacting bodies is permitted.
• Each contact detection point always interacts with the same target element which is determined from the initial configuration.
Advantages: • The small-sliding logic also improves solution robustness. It can easily solve certain
complex contact models for which the finite-sliding logic would have difficulties or find no solution. This is especially true for models having a bad quality geometry or mesh and non-smooth contact interfaces.
• The nodal connectivity of the contact element remains unchanged throughout the analysis. Contact searching is performed only once in the beginning of the analysis. which is cost-effective.
• The sparse solver can reuse the same matrix structure throughout the simulation, which avoids the costly sequential step of equation ordering at every equilibrium iteration and leads to great performance improvements and better scalability in DMP run.
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Bolt Assembly Model
1. Apply bolt and strap clamp forces
2. Adjust bolt and strap increment
3. Fix bolt and strap
4. Vertical up 6g
5. Vertical down 8g
Improve contact robustness (Bolt Assembly model)
Not actual model
Small Sliding + Normal Lagrange
multipliers
86 iterations for 5 load steps (no bisections)
55 iterations for first load step
11836 sec wall time using 16 CPUs
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Nonlinear Mesh Adaptivity for Extreme Mesh DistortionNLAD
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Introduction to Mesh Nonlinear Adaptivity
Unlike manual rezoning, mesh nonlinear adaptivity is completely automatic, requiring no user input during solution.
Automatic During Solution
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Automation - Nonlinear Adaptive Remeshing
Rubber Seal
Electronic 2 Pin Connector
34 Times Remeshing
Lower Order Tetrahedral SOLID285
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• Very large deformation
• Maximum number of re-meshings: 99
Metal Extrusion
Higher Order Tetrahedral SOLID187
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Composites Analysis
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• Assumption: REINFs are securely bonded with the base material. No relative movement between REINFs and the base material is allowed.
• REINFs are modeled with separate reinforcing elements and coupled with the base elements through common nodes
Base element REINF element
=
Reinforced element
Reinforcing Elements -- Modeling Approach
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• Reinforcing in line (fiber) or surface (ply) forms are meshed independently with MEHS200 elements
• Other REINF information, including material , coordinate system, area/thickness, spacing, is associated with the MESH200 elements, via REINF sections, and/or element data (MAT, ESYS, etc.)
• Issue EREINF command
MESH200 + BASE → REINF elements
Mesh Independent Method
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Reinforced Concrete Beam 4 point bending
- Reinforced concrete beam- Base material: microplane w/ elastic damage- REINF: Steel Rebars- 4-point bending test- Experiments by Vasudevan, 2012
Elastic Base damage
Rebars:REINF264 (BISO)
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Reinforced Concrete Beam 4 point bending (contd.)
- Reinforced concrete beam- 4-point bending test- Experiments by Vasudevan, 2012
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Tire Modeling
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Tire Performance Analysis
ANSYS Mechanical has a rich set of
capabilities to study performance of
Tires. These include
• Tire Forming (Polyflow)
• Rim Mounting of Tires
• Inflation of Tires
• Fiber Reinforcement modeling
• Footprint Analysis
• Steady State Rolling of Tires
• Cornering Analysis
• Hydroplaning Analysis (ANSYS
Mechanical CFD)
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Examples of 2D to 3D analysis
Realistic Tire Model:
Von Mises Stress Plot
SEQV Plot
Total plastic strain
EPTOEQV Plot
Section View
EEXTRUDE,Tire
EEXTRUDE,Tire
Map2dto3d
Map2dto3d
Section View
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Results at Free Rolling State
Following result plots are from free rolling state
Unit : m/s
Von-Mises total strain plotVelocity vector sum plot
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Modeling of strain softening materials
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Modeling of strain softening materials
Possible areas of application:
Modeling of concrete, granular
materials, powder compaction
Induced anisotropy due to
microplane approach
Strain softening
Stiffness reduction with damage
Stiffness recovery in compression
due to crack closure
Coupled damage-plasticity Shin et. al. [2016]
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Microplane Approach
Kuhl [2000]
• Induced anisotropy due to microplane approach
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Advantages of new approach
• Well-known mesh sensitivity and loss of convergence of classical smeared cracking concrete models is overcome
• Progressive softening behavior simulated until virtually total failure (independent of the mesh refinement and with quadratic convergence)
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• Size effects is accounted for automatically in this approach by means of the nonlocal interaction, which introduces a characteristic length in the model.
• The plasticity yield function provides a general description of concrete in all triaxial stress states, also under very high confinement pressure.
• The damage split enables the simulation of concrete under random cyclic loading histories
30 © 2017 ANSYS, Inc. July 4, 2018
Reinforced concrete (RC) joint example (contd.)Force-displacement curve
Total Damage Equivalent plastic strain
Plastic strain in reinforcement
- Softening caused by a strong evolution of plasticity and compression damage in the middle of the joint
- Plasticity localized in a narrower zone than the damage
- Damage is diffused and extends outside the plastic zone
- Recall: Gradient enhancement is applied for damage only
31 © 2017 ANSYS, Inc. July 4, 2018
Fracture: Crack Growth Simulation
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Objectives
• Develops automatic, robust and effective crack growth
modeling method
• Provides easy to use crack modeling tools to predict:
Stress Intensity Factors, Crack Growth Rates, Critical
Crack Sizes, Crack Paths
What is SMART Crack Growth Method
• SMART stands for Separation, Morphing, Adaptive and
Remeshing Technique
• Integrates morphing, adaptive and remeshing
technology into FEA solution kernel – substep level
• Integrates the crack growth into APDL solution kernel for
best performance
• Remeshing only local to crack front region
• Meshing update due to crack growth is automatic
• End to end solution in WB Mechanical
• Support both static and fatigue crack growth modeling
SMART Crack Growth Simulation Method
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SMART Crack Growth Simulation Method
Experiment
Problem description
• Compact tension specimen with a hole
• Fatigue crack growth with Paris Law
• Small strain linear elasticity
• SOLID187
• Displacement loading
• Crack propagation with material force apprach
R19 development
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Additive Manufacturing & Topology Optimization
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Topology OptimizationEnables superior designs via physics-driven free-
form design optimizationTopological
Optimization
Validation
Geometry
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Topological Optimization for Additive Example
Wheel
In cooperation with TH Ingolstadt / AUDI
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Validation and Comparison
The comparison shows that stress and deformation can be improved with the same amount of material
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Mass [%] Deformation [%] Stress [%]
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What will be beta in 19.x
• Support for Non-linear contacts
B.C. Bonded contact Nonlinear contact
39 © 2017 ANSYS, Inc. July 4, 2018
Process Simulation Example
Transient thermal simulation of layers being built Static structural showing build-up of deformation
40 © 2017 ANSYS, Inc. July 4, 2018
ANSYS is your First Choice !Do you ever have simulation needs beyond pure structural mechanics?
• ANSYS Mechanical product packaging consolidation
Does your CAD package bi-directionally talk to your simulation software?
• ANSYS offers industry-leading CAD-neutral interface tools
Have you ever considered external mesh tools?
• Workbench provides the best world-class mesh
How much effort do you expend running many multiple what-if scenarios?
• Workbench is built for this… set up your model once, easily vary parameters
Do your analysts use simulation every day?
• Workbench’s ease-of-use and natural, logical layout
How long since you last took at ANSYS MAPDL?
• Many new breakthrough technologies have been added in MAPDL
Do you know 10 node tetrahedral elements are available for all ANSYS Mechanical features?
• Meshing, Contact, NLAD and Fracture … modeling techniques were built on it
41 © 2017 ANSYS, Inc. July 4, 2018
Thank You