Create a rotor dynamic solution

1. In the Solution dialog box, select the solution type from the Solution Type list.For a complex eigenvalue rotor dynamic analysis, select either SOL 107 Direct Complex Eigenvalues or SOL 110 Modal Complex Eigenvalues.For a frequency response rotor dynamic analysis, select either SOL 108 Direct Frequency Response or SOL 111 Modal Frequency Response.For a transient response rotor dynamic analysis, select either SOL 109 Direct Transient Response or SOL 112 Modal Transient Response.

2. (Optional) If you select SOL 107 Direct Complex Eigenvalues, specify complex modal reduction.In the Solution dialog box, click the Case Control tab.Next to Complex Mode Reduction, click Create Modeling Object .In the Complex Eigenvalue dialog box, specify the parameters for the complex modal reduction.

3. Specify the Simcenter Nastran parameters.In the Solution dialog box, click the Parameters tab.(Optional) Select the Rotor Dynamics CSV Output check box to request Simcenter Nastran write a .csv file.Next to Parameters, click Create Modeling Object .In the Solution Parameters dialog box, expand the appropriate group and specify the parameter.Next to the parameter, click Add and then click OK.In the Solution dialog box, click OK.The following parameters are typically relevant in rotor dynamic analysis:For any rotor dynamics analysis, you must turn off residual vectors. To do so, in the Q-R group, from the RESVEC list, select NO.For any rotor dynamics analysis, if your model has any combination of unsymmetric stiffness, unsymmetric viscous damping, and structural damping, or if the default method fails to adequately track the modes, switch to the mode tracking method introduced with NX Nastran 8.5. To do so, in the M-N group, in the MODTRK box, type 3.(Optional) For either SOL 107 Direct Complex Eigenvalues or SOL 110 Modal Complex Eigenvalues, you can optionally do the following:Skip synchronous analysis. To do so, in the Q-R group, from the ROTSYNC list, select NO.Request Simcenter Nastran write a .csv file. The .csv file contains the complex eigenvalue rotor dynamic analysis results needed to create a Campbell diagram. If you cleared the Rotor Dynamics CSV Output check box and still want to request a .csv file, expand the Q-R group. In the ROTCSV box, type the FORTRAN unit number.Request Simcenter Nastran write a .gpf file. The .gpf file contains the complex eigenvalue rotor dynamic analysis results needed to create a Campbell diagram. To request a .gpf file, expand the Q-R group. In the ROTGPF box, type the FORTRAN unit number.

4. (Optional) To account for centrifugal stiffening or softening of the rotor, create a statics subcase and a dynamics subcase.In the Solution Step dialog box, select Subcase – Statics from the Step list.Click OK.To create a dynamic subcase, in the Simulation Navigator, right-click the solution and choose New Subcase.In the Solution Step dialog box, select the appropriate dynamic subcase from the Step list.Click OK.When you specify the boundary conditions for the model, use the Rotation command to apply a centrifugal load.For information on how to do this, see Model centrifugal stiffening and softening in rotor dynamic analysis.

How do I

Define bearing supports between coincident nodes with CBEAR elements

Assign physical properties to CBEAR elements

Define rotors

Define the superelement reduction for a rotor

Map CBEAR elements to rotors

Define stationary nodes for CBEAR elements

Define system-wide rotor dynamics solution options

Define rotor-specific rotor dynamics solution options

Specify mode filtering

Model centrifugal stiffening and softening in rotor dynamic analysis

Model mass imbalance in rotor dynamic analysis

Create a Campbell diagram

Learn more

Rotor dynamics

Rotor dynamics workflow

Supported solution types for rotor dynamic analysis

Quick links

Command reference

Pre/Post video examples

Bulk Entry Descriptions

Simcenter 3D tutorials

Browse Simcenter 3D help by product area

Create a rotor dynamic solution, Simcenter 3D 2021.1 Series

© 2020 Siemens

window.mainLanguage="en_US"

window.delivId=""

window.projectId=""

MathJax.Hub.Config({ TeX: { extensions: ["autoload-all.js"] }, tex2jax: { displayMath: [ ] }, "SVG": { scale: 125 } });