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1. Contact Overview
1.1. Contact Analysis Types
1.2. Comparison of Pair-Based Contact and General Contact
1.2.1. Choosing Between Pair-Based Contact and General Contact
1.2.2. Difference in Default Settings
1.2.3. Features Not Supported by General Contact
1.3. Contact Element Capabilities
1.3.1. Surface-to-Surface Contact Elements
1.3.2. Node-to-Surface Contact Elements
1.3.3. 3D Line-to-Line Contact
1.3.4. Line-to-Surface Contact
1.3.5. Node-to-Node Contact Elements
2. GUI Aids for Contact Analyses
2.1. The Contact Manager
2.2. The Contact Wizard
2.3. Managing Contact Pairs
3. Surface-to-Surface Contact (Pair-Based)
3.1. Using Surface-to-Surface Contact Elements
3.2. Steps in a Contact Analysis
3.3. Creating the Model Geometry and Mesh
3.4. Identifying Contact Pairs
3.5. Designating Contact and Target Surfaces
3.5.1. Asymmetric Contact vs. Symmetric Contact
3.6. Defining the Target Surface
3.6.1. Pilot Nodes
3.6.2. Primitives
3.6.3. Element Types and Real Constants
3.6.4. Using Direct Generation to Create Rigid Target Elements
3.6.5. Using Meshing Tools to Create Rigid Target Elements
3.6.6. Double-Sided Target Surfaces
3.7. Defining the Deformable Contact Surface
3.7.1. Element Type
3.7.2. Real Constants and Material Properties
3.7.3. Generating Contact Elements
3.8. Geometry Correction for Contact and Target Surfaces
3.8.1. Surface Smoothing
3.8.2. User-Defined Contact Surface Normal
3.8.3. Simplified Bolt Thread Modeling
3.9. Set the Real Constants and Element KEYOPTS
3.9.1. Real Constants
3.9.2. Element KEYOPTS
3.9.3. Selecting a Contact Algorithm (KEYOPT(2))
3.9.4. Determining Contact Stiffness and Allowable Penetration
3.9.5. Choosing a Friction Model
3.9.6. Selecting Location of Contact Detection
3.9.7. Selecting a Sliding Behavior
3.9.8. Adjusting Initial Contact Conditions
3.9.9. Modeling Interference Fit
3.9.10. Physically Moving Contact Nodes Toward the Target Surface
3.9.11. Physically Moving the Target Body Toward the Contact Surface
3.9.12. Determining Contact Status and the Pinball Region
3.9.13. Avoiding Spurious Contact in Self Contact Problems
3.9.14. Selecting Surface Interaction Models
3.9.15. Using KEYOPT(3) to Control Units of Contact Stiffness and Stress State
3.9.16. Modeling Contact with Superelements
3.9.17. Modeling Contact for 2D Axisymmetric Elements with Torsion
3.9.18. Applying Contact Stabilization Damping
3.9.19. Modeling Interface Damping in Assembled Structures
3.9.20. Accounting for Thickness Effect
3.9.21. Using Time Step Control and Impact Constraints
3.9.22. Using the Birth and Death Options
3.10. User-Defined Subroutines for Contact Interfacial Behaviors
3.10.1. Defining Your Own Real Constant (USERCNPROP)
3.10.2. Writing Your Own Friction Law (USERFRIC)
3.10.3. Defining Your Own Contact Interaction (USERINTER)
3.10.4. Defining Your Own Contact Surface Wear Behavior (USERWEAR)
3.11. Controlling the Motion of the Rigid Target Surface
3.12. Applying Necessary Boundary Conditions to the Deformable Elements
3.13. Checking Contact Pair-Based Force Convergence
3.14. Applying Fluid-Pressure-Penetration Loads
3.14.1. Applying Fluid-Penetration Pressure
3.14.2. Specifying Fluid Penetration Starting Points
3.14.3. Specifying a Pressure-Penetration Criterion
3.14.4. Specifying a Fluid Penetration Acting Time
3.14.5. Redefining or Modifying the Pressure-Penetration Loads
3.14.6. Postprocessing Fluid-Pressure-Penetration Loads
3.15. Defining Solution and Load Step Options
3.16. Solving Large Contact Models in a Distributed-Memory Parallel Environment
3.16.1. Splitting Large Contact Pairs
3.16.2. Defining the Maximum Number of Sub-Pairs
3.16.3. Defining Specific Contact Pairs to be Split
3.16.4. Real Constant Set IDs for Split Pairs
3.16.5. Overlapping Contact Elements at Split Boundaries
3.16.6. Merging Split Contact Pairs
3.16.7. Trimming Split Contact Pairs
3.16.8. Limitations and Solution Consistency for Contact Splitting
3.17. Solving the Problem
3.18. Contact Behavior in Linear Analyses
3.19. Reviewing the Results
3.19.1. Points to Remember
3.19.2. Reviewing Results in POST1
3.19.3. Reviewing Results in POST26
3.19.4. Reviewing Contact Results in the Jobname.cnd File
4. Node-to-Surface Contact
4.1. The Node-to-Surface Contact Element
4.2. Performing a Node-to-Surface Contact Analysis
4.2.1. CONTA175 KEYOPTs
4.2.2. CONTA175 Real Constants
4.3. Using CONTA175 for Multiphysics Contact
5. 3D Beam-to-Beam Contact (Pair-Based)
5.1. The 3D Line Contact Element
5.2. Modeling Beam-to-Beam Contact
5.3. Performing a 3D Beam-to-Beam Contact Analysis
5.3.1. KEYOPTs and Real Constants
6. Line-to-Surface Contact (Pair-Based)
6.1. The 3D Line-to-Surface Contact Element
6.2. Performing a 3D Line-to-Surface Contact Analysis
6.2.1. KEYOPTs and Real Constants
7. Multiphysics Contact
7.1. Modeling Thermal Contact
7.1.1. Thermal Contact Behavior vs. Contact Status
7.1.2. Free Thermal Surface
7.1.3. Temperature on Target Surface
7.1.4. Modeling Conduction
7.1.5. Modeling Convection
7.1.6. Modeling Radiation
7.1.7. Modeling Heat Generation Due to Friction
7.1.8. Modeling External Heat Flux
7.1.9. Modeling Heat Transfer Among Thermal Shells
7.2. Modeling Electric Contact
7.2.1. Modeling Surface Interaction
7.2.2. Modeling Heat Generation Due to Electric Current
7.3. Modeling Magnetic Contact
7.3.1. Using MCC
7.3.2. Modeling Perfect Magnetic Contact
7.4. Modeling Pore Fluid Flow at the Contact Interface
7.4.1. Pore Fluid Permeability Across Two Contacting or Near-Field Surfaces
7.4.2. Pore Fluid Volume Flow for Near-Field Contact
7.4.3. Pore Fluid Flow from Far-Field Contact to the Environment
7.4.4. Coupled Heat Transfer with Pore Fluid Flow
7.5. Modeling Diffusion Flow at the Contact Interface
7.5.1. Diffusion Flow Across Two Contacting or Near-Field Surfaces
7.5.2. Diffusion Flow from Far-Field Contact to the Environment
8. General Contact
8.1. General Contact Overview
8.2. Modeling General Contact - Basic Procedure
8.3. Creating Rigid Target Surfaces
8.4. Generating General Contact Surfaces (GCGEN Command)
8.4.1. GCGEN Command Action (Option)
8.4.2. Edge Control Key (EdgeKEY)
8.4.3. Surface Splitting Key (SplitKEY)
8.4.4. Feature Angle (FeatureANGLE)
8.4.5. Base Element Selection (SelOpt)
8.5. Identifying General Contact Surfaces
8.5.1. Using Section IDs to Identify Surfaces
8.5.2. Using Nodal Components to Identify Surfaces
8.6. Applying Surface Geometry Correction
8.7. Defining Non-Default Contact Settings
8.8. Defining Contact Interactions (GCDEF Command)
8.8.1. Specifying General Contact Interactions Between Surfaces
8.8.2. Specifying General Contact Interactions Between Nodal Components
8.8.3. Specifying General Contact Interactions for the Entire Model
8.8.4. Specifying Contact Exclusions
8.8.5. Assigning Interface Pairing Options
8.8.6. Deleting Specified General Contact Interactions
8.9. Managing Contact Interactions Between Surfaces
8.9.1. GCDEF Command Entries and Execution
8.9.2. The LIST and TABLE Options of GCDEF
8.9.3. Example of How to Use the LIST and TABLE Options
8.9.4. Retrieving Information with *GET Commands
8.10. Defining Interface Behavior
8.10.1. Friction
8.10.2. Contact Interaction Options Specified via TB
8.11. Assigning Contact Properties via Real Constants
8.12. Other Useful Tools for General Contact
8.12.1. Checking Initial Contact Status (CNCHECK Command)
8.12.2. Tracking Contact Results (NLHIST Command)
8.12.3. Setting Contact Diagnostics (NLDIAG Command)
8.12.4. Creating General Contact Elements Manually
8.12.5. Converting Pair-Based Contact to General Contact
9. Node-to-Node Contact
9.1. Node-to-Node Contact Elements
9.2. Performing a Node-to-Node Contact Analysis
9.2.1. Creating Geometry and Meshing the Model
9.2.2. Generating Contact Elements
9.2.3. Defining the Contact Normal
9.2.4. Defining the Initial Interference or Gap
9.2.5. Selecting the Contact Algorithm
9.2.6. Applying Necessary Boundary Conditions
9.2.7. Defining the Solution Options
9.2.8. Solving the Problem
9.2.9. Reviewing the Results
10. Multipoint Constraints and Assemblies
10.1. Modeling Solid-Solid and Shell-Shell Assemblies
10.1.1. Choosing the Nodal Detection Method
10.1.2. Controlling Behavior at the Contact Surface
10.1.3. Controlling Degrees of Freedom Used in the MPC Constraint
10.1.4. Using the MPC Approach for Multiphysics Applications
10.2. Modeling a Shell-Solid Assembly
10.3. Surface-Based Constraints
10.3.1. Defining Surface-Based Constraints
10.3.2. Defining Influence Range (PINB)
10.3.3. Degrees of Freedom of Surface-Based Constraints
10.3.4. Specifying a Local Coordinate System
10.3.5. Additional Guidelines for a Force-Distributed Constraint
10.3.6. Additional Guidelines for a Rigid Surface Constraint
10.3.7. Additional Guidelines for a Coupling Constraint
10.3.8. Modeling a Beam-Solid Assembly
10.3.9. Force-distributed Constraint Theory Background
10.4. Modeling Rigid Bodies
10.4.1. Modeling Contact between Rigid Bodies
10.5. Overconstraint Detection and Elimination
10.5.1. Detect Overconstraint
10.5.2. Relaxation Method
10.5.3. Automatic Elimination of Overconstraint
10.6. Restrictions and Recommendations for Internal MPC
11. Dynamic Contact and Impact Modeling
11.1. Energy and Momentum Conserving Contact
11.1.1. Energy Conservation
11.1.2. Automatic Time-Stepping
11.1.3. Penetration and Relative Velocity
11.1.4. Impact Between Rigid Bodies
12. Spot Welds
12.1. Defining a Single Spot Weld Set
12.1.1. Creating a Basic Spot Weld Set with SWGEN
12.1.2. The Components of a Spot Weld
12.1.3. Adding Surfaces to a Basic Set
12.2. Generation of Multiple Spot Welds
12.2.1. Node-to-surface Configuration of Spot Welds
12.2.2. Recommendations and Limitations for Node-to-surface Configuration of Spot Welds
12.2.3. Multi-layered spot weld at multiple locations via components
12.2.4. SND1 as a Nodal Component Group
12.2.5. SND1 as an Element Component Group
12.2.6. SND1 as a Table Parameter
12.3. Listing and Deleting Spot Welds
13. Debonding
13.1. Including Debonding in a Contact Analysis
13.2. Cohesive Zone Materials Used for Debonding
13.2.1. Bilinear Material Behavior - Contact (TBOPT = CBDD and CBDE)
13.2.2. Bilinear Material Behavior - Interface (TBOPT = BILI)
13.2.3. Exponential Material Behavior
13.3. Post-Debonding Behavior of Cohesive Zone Material
13.4. Modeling Debonding with Nonlinear Adaptivity
14. Contact Surface Wear
14.1. Including Wear in a Contact Analysis
14.1.1. Wear Models
14.1.2. Geometry Update Due to Wear
14.1.3. Improving Mesh Quality During Wear
14.1.4. Automatic Scaling of Wear Increment
14.1.5. Cycle-By-Cycle Wear Scaling
14.1.6. Assumptions and Restrictions
14.1.7. Postprocessing
A. Example 2D Contact Analysis with Fluid Pressure-Penetration Loading
A.1. Problem Description
A.2. Input File