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GP-ME-0F545PAMechanicalReady

ROSS rotordynamic critical-speed study

A ROSS finite-element study of critical speeds, Campbell branches, synchronous unbalance response, bearing sensitivity, mesh convergence, stability, and uncertainty for a two-disk flexible rotor.

ROSS rotordynamic critical-speed study project visual
GP-ME-0F545PA · Mechanical
  • Python
  • ROSS 2.3.0
  • NumPy
  • SciPy
  • Pandas
  • Matplotlib
  • Jupyter

Project definition

Problem statement

A flexible rotor can cross bending resonances, respond strongly to residual unbalance, or become unstable through support cross-coupling even when its static design appears satisfactory.

The engineering problem is to connect the rotor model, Campbell intersections, forced response, bearing behavior, mesh resolution, stability, and parameter uncertainty in one traceable study.

Project objectives

  • Build a 1.2 m steel shaft with twelve Timoshenko elements, two rigid disks, and two anisotropic bearings.
  • Calculate speed-dependent modes, damped critical speeds, logarithmic decrement, unbalance response, and disk orbit.
  • Measure sensitivity to direct bearing stiffness and damping.
  • Verify the first modes across six, twelve, and twenty-four shaft elements.
  • Map cross-coupled instability and propagate sixty seeded parameter combinations.

Project structure

Project components

01

Rotor model

Validates the configuration and assembles ROSS shaft, disk, and bearing elements.

02

Modal analysis

Calculates speed-dependent whirl branches, damping, and critical-speed intersections.

03

Forced response

Applies a declared 20 g mm unbalance and retains amplitudes, peaks, and disk orbit.

04

Sensitivity studies

Varies direct bearing stiffness, damping, mesh count, and parameter uncertainty.

05

Stability study

Maps minimum logarithmic decrement against speed and imposed cross-coupled stiffness.

06

Evidence pipeline

Writes complete CSV, JSON, NPZ, figure, test, and document evidence.

Methodology

Project workflow

  1. 01
    Build the rotor

    The shaft, two disks, and two end bearings are assembled from the released SI-unit configuration.

  2. 02
    Solve the modes

    ROSS calculates damped modes and one-times critical-speed intersections from 0 to 12000 rpm.

  3. 03
    Apply unbalance

    A synchronous rotating force is applied at the second disk across the complete speed sweep.

  4. 04
    Test the model

    Support, mesh, stability, and uncertainty experiments challenge the baseline assumptions.

  5. 05
    Review the evidence

    Tables, figures, tests, and independent checks are interpreted with the declared validity boundary.

Demonstration scenario

The released rotor has first damped critical speeds of 1506.26 and 1575.18 rpm. A 20 g mm unbalance produces a 10.745 micrometre maximum at 1558.50 rpm, while sixty uncertainty cases place the first mode between 1405.41 and 1589.70 rpm.

Engineering

Tools and method

Tools
The project uses Python, ROSS 2.3.0, NumPy, SciPy, Pandas, Matplotlib, Jupyter for subject analysis, simulation, and results.
Finite elements
ROSS 2.3.0 Timoshenko shaft elements with rigid disks, gyroscopic action, and linear bearings.
Numerical analysis
NumPy and SciPy support controlled sweeps, peak calculations, and retained arrays.
Evidence
Pandas, JSON, NPZ, and Matplotlib provide complete machine-readable and graphical results.
Verification
Mesh refinement, independent trend checks, 64 tests, full core branch coverage, and dependency audit.

Testing

Evaluation

Evaluation measures

  • Damped critical-speed locations and whirl direction
  • Synchronous response peak and disk orbit
  • Rated-speed separation from critical-speed regions
  • Bearing stiffness and damping sensitivity
  • Residual mesh error from twelve to twenty-four elements
  • Cross-coupled stability boundary and sixty-case uncertainty range

Project boundaries

  • The dimensions, disk properties, bearing coefficients, and uncertainty bounds are illustrative and do not describe a named machine.
  • The model uses linear bearings and does not include seals, foundation flexibility, nonlinear contact, rub, cracks, thermal bow, torsion, shaft stress, or fatigue.
  • The stability sweep uses imposed cross-coupled stiffness and is not a measured seal or fluid-film bearing model.
  • Results support learning and comparative analysis, not balancing acceptance, machinery certification, or permission to operate rotating hardware.

Included

  1. 01Complete Python and ROSS source code
  2. 02Modal, critical-speed, unbalance, bearing, mesh, stability, and uncertainty studies
  3. 03Nine complete analysis tables, one NPZ archive, and fourteen project figures
  4. 0471-page project report in PDF and editable Word formats
  5. 0517-page setup and usage guide in PDF and editable Word formats
  6. 0650 annotated references and three attributed literature images
  7. 0764 automated tests with 100 percent branch-aware core coverage

Project record

No information is collected on this page.

Permanent project ID
GP-ME-0F545PA
Catalogued
21 Aug 2026
Completed
26 Aug 2026
Verified
26 Aug 2026
Demonstration
Included in repository

Handover

After purchase

  1. 01
    Payment is confirmed

    The project is marked unavailable and cannot be purchased again.

  2. 02
    Repository access is granted

    The buyer's submitted GitHub account receives access to the private repository.

  3. 03
    The purchase record is delivered

    The certification sheet is prepared from the reviewed buyer details and sent privately by email.