Mechanical APDL Basic Analysis Guide - Ansys
Mechanical APDL Basic Analysis Guide - Ansys Mechanical APDL Basic Analysis Guide - Ansys
Chapter 2: Loading Command(s): SBCTRAN GUI: Main Menu> Preprocessor> Loads> Define Loads> Operate> Transfer to FE> All Solid Lds Main Menu> Solution> Define Loads> Operate> Transfer to FE> All Solid Lds 2.5.5.1. Resetting Constraints By default, if you repeat a DOF constraint on the same degree of freedom, the new specification replaces the previous one. You can change this default to add (for accumulation) or ignore with the DCUM command (Main Menu> Preprocessor> Loads> Define Loads> Settings> Replace vs. Add> Constraints). For example: NSEL,... ! Selects a set of nodes D,ALL,VX,40 ! Sets VX = 40 at all selected nodes D,ALL,VX,50 ! Changes VX value to 50 (replacement) DCUM,ADD ! Subsequent D's to be added D,ALL,VX,25 ! VX = 50+25 = 75 at all selected nodes DCUM,IGNORE ! Subsequent D's to be ignored D,ALL,VX,1325 ! These VX values are ignored! DCUM ! Resets DCUM to default (replacement) See the Command Reference for discussions of the NSEL,D, and DCUM commands. Any DOF constraints you set with DCUM stay set until another DCUM is issued. To reset the default setting (replacement), simply issue DCUM without any arguments. 2.5.5.2. Scaling Constraint Values You can scale existing DOF constraint values as follows: Command(s): DSCALE GUI: Main Menu> Preprocessor> Loads> Define Loads> Operate> Scale FE Loads> Constraints Main Menu> Solution> Define Loads> Operate> Scale FE Loads> Constraints Both the DSCALE and DCUM commands work on all selected nodes and also on all selected DOF labels. By default, DOF labels that are active are those associated with the element types in the model: Command(s): DOFSEL GUI: Main Menu> Preprocessor> Loads> Define Loads> Operate> Scale FE Loads> Constraints (or Forces) Main Menu> Preprocessor> Loads> Define Loads> Settings> Replace vs. Add> Constraints (or Forces) Main Menu> Solution> Define Loads> Operate> Scale FE Loads> Constraints (or Forces) Main Menu> Solution> Define Loads> Settings> Replace vs. Add> Constraints (or Forces) For example, if you want to scale only VX values and not any other DOF label, you can use the following commands: DOFSEL,S,VX ! Selects VX label DSCALE,0.5 ! Scales VX at all selected nodes by 0.5 DOFSEL,ALL ! Reactivates all DOF labels DSCALE and DCUM also affect velocity and acceleration loads applied in a structural analysis. When scaling temperature constraints (TEMP) in a thermal analysis, you can use the TBASE field on the DSCALE command to scale the temperature offset from a base temperature (that is, to scale |TEMP-TBASE|) rather than the actual temperature values. The following figure illustrates this. 30 Release 13.0 - © SAS IP, Inc. All rights reserved. - Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.
Figure 2.7 Scaling Temperature Constraints with DSCALE 2.5.5.3. Resolution of Conflicting Constraint Specifications You need to be aware of the possibility of conflicting DK, DL, and DA constraint specifications and how the ANSYS program handles them. The following conflicts can arise: • A DL specification can conflict with a DL specification on an adjacent line (shared keypoint). • A DL specification can conflict with a DK specification at either keypoint. • A DA specification can conflict with a DA specification on an adjacent area (shared lines/keypoints). • A DA specification can conflict with a DL specification on any of its lines. • A DA specification can conflict with a DK specification on any of its keypoints. The ANSYS program transfers constraints that have been applied to the solid model to the corresponding finite element model in the following sequence: 1. In ascending area number order, DOF DA constraints transfer to nodes on areas (and bounding lines and keypoints). 2. In ascending area number order, SYMM and ASYM DA constraints transfer to nodes on areas (and bounding lines and keypoints). 3. In ascending line number order, DOF DL constraints transfer to nodes on lines (and bounding keypoints). 4. In ascending line number order, SYMM and ASYM DL constraints transfer to nodes on lines (and bounding keypoints). 5. DK constraints transfer to nodes on keypoints (and on attached lines, areas, and volumes if expansion conditions are met). Accordingly, for conflicting constraints, DK commands overwrite DL commands and DL commands overwrite DA commands. For conflicting constraints, constraints specified for a higher line number or area number overwrite the constraints specified for a lower line number or area number, respectively. The constraint specification issue order does not matter. Release 13.0 - © SAS IP, Inc. All rights reserved. - Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates. 2.5.5.Transferring Constraints 31
- Page 1 and 2: ANSYS Mechanical APDL Basic Analysi
- Page 3 and 4: Table of Contents 1. Getting Starte
- Page 5 and 6: 2.8.4.3. Define Material Properties
- Page 7 and 8: 7.2.1.6. Particle Flow and Charged
- Page 9 and 10: 10. Getting Started with Graphics .
- Page 11 and 12: 13.2.4.1.Turning Load Symbols and C
- Page 13 and 14: 20.8. Reviewing Contents of Binary
- Page 15 and 16: List of Tables 2.1. DOF Constraints
- Page 17 and 18: Chapter 1: Getting Started with ANS
- Page 19 and 20: shown below define two element type
- Page 21 and 22: You can choose constant, isotropic,
- Page 23 and 24: You can save linear material proper
- Page 25 and 26: Figure 1.4 Material Model Interface
- Page 27 and 28: Figure 1.7 Data Input Dialog Box -
- Page 29 and 30: The first example below is intended
- Page 31 and 32: 9. Click on OK. The dialog box clos
- Page 33 and 34: 1.1.4.9. Reading a Material Library
- Page 35 and 36: If you are performing a static or f
- Page 37 and 38: Chapter 2: Loading The primary obje
- Page 39 and 40: Figure 2.2 Transient Load History C
- Page 41 and 42: The arc-length method is an advance
- Page 43 and 44: • Transferred solid loads will re
- Page 45: Note If the node rotation angles th
- Page 49 and 50: Below are examples of some of the G
- Page 51 and 52: Utility Menu> List> Loads> Surface>
- Page 53 and 54: Figure 2.9 Example of Surface Load
- Page 55 and 56: the shell, and 270° to 360° for t
- Page 57 and 58: Below are examples of some of the G
- Page 59 and 60: Figure 2.15 Transfers to BFK Loads
- Page 61 and 62: CASE C: At least one BFV, BFA, or B
- Page 63 and 64: A handy way to specify density so t
- Page 65 and 66: For more information, see Initial S
- Page 67 and 68: Boundary Condition Heat Flux Film C
- Page 69 and 70: This problem consists of a thermal-
- Page 71 and 72: 2.6. Specifying Load Step Options A
- Page 73 and 74: - All loads changed in later load s
- Page 75 and 76: Main Menu> Preprocessor> Loads> Loa
- Page 77 and 78: Command GUI Menu Paths Main Menu> S
- Page 79 and 80: ! Load Step 1: D, ... ! Loads SF, .
- Page 81 and 82: Modeling> Create> Elements> Auto Nu
- Page 83 and 84: Figure 2.22 Pretension Section Samp
- Page 85 and 86: cylind,0.35,1, 0.75,1, 0,180 wpstyl
- Page 87 and 88: 11. Select Utility Menu> PlotCtrls>
- Page 89 and 90: 24. Select Utility Menu> Plot> Comp
- Page 91 and 92: Chapter 3: Using the Function Tool
- Page 93 and 94: Hint: A common error is a divide-by
- Page 95 and 96: 3.3. Using the Function Loader When
Chapter 2: Loading<br />
Command(s): SBCTRAN<br />
GUI: Main Menu> Preprocessor> Loads> Define Loads> Operate> Transfer to FE> All Solid Lds<br />
Main Menu> Solution> Define Loads> Operate> Transfer to FE> All Solid Lds<br />
2.5.5.1. Resetting Constraints<br />
By default, if you repeat a DOF constraint on the same degree of freedom, the new specification replaces<br />
the previous one. You can change this default to add (for accumulation) or ignore with the DCUM command<br />
(Main Menu> Preprocessor> Loads> Define Loads> Settings> Replace vs. Add> Constraints). For example:<br />
NSEL,... ! Selects a set of nodes<br />
D,ALL,VX,40 ! Sets VX = 40 at all selected nodes<br />
D,ALL,VX,50 ! Changes VX value to 50 (replacement)<br />
DCUM,ADD ! Subsequent D's to be added<br />
D,ALL,VX,25 ! VX = 50+25 = 75 at all selected nodes<br />
DCUM,IGNORE ! Subsequent D's to be ignored<br />
D,ALL,VX,1325 ! These VX values are ignored!<br />
DCUM ! Resets DCUM to default (replacement)<br />
See the Command Reference for discussions of the NSEL,D, and DCUM commands.<br />
Any DOF constraints you set with DCUM stay set until another DCUM is issued. To reset the default setting<br />
(replacement), simply issue DCUM without any arguments.<br />
2.5.5.2. Scaling Constraint Values<br />
You can scale existing DOF constraint values as follows:<br />
Command(s): DSCALE<br />
GUI: Main Menu> Preprocessor> Loads> Define Loads> Operate> Scale FE Loads> Constraints<br />
Main Menu> Solution> Define Loads> Operate> Scale FE Loads> Constraints<br />
Both the DSCALE and DCUM commands work on all selected nodes and also on all selected DOF labels. By<br />
default, DOF labels that are active are those associated with the element types in the model:<br />
Command(s): DOFSEL<br />
GUI: Main Menu> Preprocessor> Loads> Define Loads> Operate> Scale FE Loads> Constraints (or<br />
Forces)<br />
Main Menu> Preprocessor> Loads> Define Loads> Settings> Replace vs. Add> Constraints (or<br />
Forces)<br />
Main Menu> Solution> Define Loads> Operate> Scale FE Loads> Constraints (or Forces)<br />
Main Menu> Solution> Define Loads> Settings> Replace vs. Add> Constraints (or Forces)<br />
For example, if you want to scale only VX values and not any other DOF label, you can use the following<br />
commands:<br />
DOFSEL,S,VX ! Selects VX label<br />
DSCALE,0.5 ! Scales VX at all selected nodes by 0.5<br />
DOFSEL,ALL ! Reactivates all DOF labels<br />
DSCALE and DCUM also affect velocity and acceleration loads applied in a structural analysis.<br />
When scaling temperature constraints (TEMP) in a thermal analysis, you can use the TBASE field on the<br />
DSCALE command to scale the temperature offset from a base temperature (that is, to scale |TEMP-TBASE|)<br />
rather than the actual temperature values. The following figure illustrates this.<br />
30<br />
Release 13.0 - © SAS IP, Inc. All rights reserved. - Contains proprietary and confidential information<br />
of ANSYS, Inc. and its subsidiaries and affiliates.
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