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1. Introduction to Rotordynamic Analysis
1.1. The General Dynamics Equations
1.2. The Benefits of the Finite Element Analysis Method for Modeling Rotating Structures
1.3. Overview of the Rotordynamic Analysis Process
2. Rotordynamic Analysis Tools
2.1. Commands Used in a Rotordynamic Analysis
2.2. Elements Used in a Rotordynamic Analysis
2.3. Terminology Used in a Rotordynamic Analysis
2.3.1. Gyroscopic Effect
2.3.2. Whirl
2.3.3. Elliptical Orbit
2.3.4. Stability
2.3.5. Critical Speed
2.3.6. Critical Speed Map
2.4. Rotordynamics Reference Sources
2.4.1. Internal References
2.4.2. External References
3. Modeling a Rotordynamic Analysis
3.1. Building the Model
3.2. Modeling Parts
3.3. Modeling Bearings
3.3.1. Using the COMBIN14 Element
3.3.2. Using the COMBI214 Element
3.3.3. Using the FLUID218 Element
3.3.4. Using the MATRIX27 Element
3.3.5. Using the MPC184 General Joint Element
3.4. Modeling Hints and Examples
3.4.1. Adding a Stationary Part
3.4.2. Transforming Non-Axisymmetric Parts into Equivalent Axisymmetric Mass
3.4.3. Defining Multiple Spools
3.4.4. Using Component Mode Synthesis (CMS) for Rotating Parts
3.4.5. Verifying Your Model with the Rotor Mass Summary Printout
4. Applying Loads and Constraints in a Rotordynamic Analysis
4.1. Applying Quasi-Static Loads
4.2. Defining Rotating Forces
4.2.1. Rotating Forces in Transient Analysis
4.2.2. Rotating Forces in Harmonic Analysis
5. Solving a Rotordynamic Analysis
5.1. Adding Damping
5.2. Specifying Rotational Velocity and Accounting for the Gyroscopic Effect
5.3. Solving for a Subsequent Campbell Analysis of a Prestressed Structure Using the Linear Perturbation Procedure
5.4. Solving a Harmonic Analysis with Synchronous or Asynchronous Rotating Forces
5.4.1. Specifying Rotational Velocity with OMEGA
5.4.2. Specifying Rotational Velocity with CMOMEGA
5.5. Selecting an Appropriate Solver
5.5.1. Solver for a Modal Analysis
5.5.2. Solver for a Harmonic Analysis
5.5.3. Solver for a Transient Analysis
5.6. Using Linear Perturbation Modal Analysis
6. Postprocessing a Rotordynamic Analysis
6.1. Postprocessing Complex Results
6.1.1. In POST1
6.1.2. In POST26
6.2. Visualizing the Orbits After a Modal or Harmonic Analysis
6.3. Printing the Orbit Characteristics After a Modal or Harmonic Analysis
6.4. Animating the Orbits After a Modal or Harmonic Analysis
6.5. Visualizing Your Orbits After a Transient Analysis
6.6. Postprocessing Bearing and Reaction Forces
6.6.1. COMBI214 Bearing Forces
6.6.2. FLUID218 Bearing Forces
6.7. Campbell Diagram
6.7.1. Visualize the Evolution of the Frequencies With the Rotational Velocity
6.7.2. Check the Stability and Whirl of Each Mode
6.7.3. Determine the Critical Speeds
6.7.4. Determine the Stability Threshold
6.7.5. Generating a Successful Campbell Diagram
7. Rotordynamic Analysis Examples
7.1. Example: Campbell Diagram Analysis of a Simply Supported Beam
7.1.1. Problem Description
7.1.2. Problem Specifications
7.1.3. Input for the Analysis
7.1.4. Analysis Steps
7.2. Example: Unbalance Harmonic Analysis
7.2.1. Problem Description
7.2.2. Problem Specifications
7.2.3. Input for the Analysis
7.2.4. Analysis Steps
7.3. Example: Mode-Superposition Harmonic Response to Base Excitation
7.3.1. Problem Specifications
7.3.2. Input for the Analysis
7.3.3. Output for the Analysis
7.4. Example: Mode-Superposition Transient Response to an Impulse
7.4.1. Problem Specifications
7.4.2. Input for the Analysis
7.4.3. Output for the Analysis
7.5. Example: Transient Response of a Startup
7.5.1. Problem Specifications
7.5.2. Input for the Analysis
7.5.3. Output for the Analysis
7.6. Example: Campbell Diagram Analysis of a Simple Rotor Supported by a CMS Superelement
7.6.1. Problem Specifications
7.6.2. Input for the Analysis
7.6.3. Outputs for the Analysis
7.7. Example: Critical Speed Map Generation
7.7.1. Input for the Analysis
7.7.2. Output for the Analysis
7.8. Example: Harmonic Response to Unbalanced Force using Component Mode Synthesis (CMS)
7.8.1. Problem Specifications
7.8.2. Input for the Analysis
7.8.3. Output for the Analysis
7.9. Example: Calculation of a Plain Cylindrical Journal Bearing Characteristics
7.9.1. Problem Specifications
7.9.2. Input for the Analysis
7.9.3. Output for the Analysis
7.10. Example: Calculation of a Squeeze Film Damper Characteristics
7.10.1. Problem Specifications
7.10.2. Input for the Analysis
7.10.3. Output for the Analysis
7.11. Example: Transient Analysis of a Plain Cylindrical Journal Bearing
7.11.1. Problem Specifications
7.11.2. Input for the Analysis
7.11.3. Output for the Analysis
7.12. Example: Calculation of the Pressure Profile of a Plain Cylindrical Journal Bearing with Supply Orifice
7.12.1. Problem Specifications
7.12.2. Input for the Analysis
7.12.3. Output for the Analysis
7.13. Example: Transient Analysis of a Plain Cylindrical Journal Bearing (3D Approach)
7.13.1. Problem Specifications
7.13.2. Input for the Analysis
7.13.3. Output for the Analysis
7.14. Example: Quasi-Static Analysis of a Multi-Rotor System
7.14.1. Problem Specifications
7.14.2. Input for the Analysis
7.14.3. Output for the Analysis
7.15. Example: Calculation of 3D Hydrodynamic Bearing Characteristics
7.15.1. Problem Specifications
7.15.2. Input for the Analysis
7.15.3. Output for the Analysis
7.16. Example: Calculation of the Pressure Profile of a Three-Lobe Journal Bearing
7.16.1. Problem Specifications
7.16.2. Input for the Analysis
7.16.3. Output for the Analysis
A. Bearing Characteristics File Format