2-D FEA Rotordynamics Analysis

Capabilities

RAPPID™ 2D finite element rotordynamics analysis software utilizes conical beam elements to enable modeling of an unlimited number of rotating and stationary structures. A variety of analyses can be completed, including:

• Free-free rotor and housing modes
• Undamped critical speeds and housing natural frequencies
• Damped eigenvalues, stability, and mode shapes
• Synchronous and asynchronous forced response
• Asynchronous response can be constant rotor speed or constant harmonic order
• Nonlinear transient forced response

Advanced Features

RAPPID™ 2D finite element rotordynamics analysis software has many flexible features, including:

• Rotors and housings may have any relative orientation in 3D space
• Each rotor and housing entity modeled with 2D conical beam elements
• Each rotating assembly is assigned a speed and direction
• Analysis of co-rotating, counter rotating, and co-axial rotors
• All DOFs are included for analysis of coupled axial, torsional, and lateral modes
• Up to 108 rotordynamic coefficients for each interconnection
• Unlimited number of forcing functions
• Forcing functions may be defined with magnitudes that are constant or a function of frequency squared

Postprocessing

RAPPID™ 2D finite element rotordynamics analysis software has unique postprocessing capabilities, including:

• Automatic generation of geometry plot with only user selected nodes and load paths
• Natural Frequency Map, Stability Map, Root Locus Plot, and 3D Mode Shapes
• Rotor modes are automatically sorted and labeled along with user defined operating range
• User defined harmoic lines are displayed and interferences automatically labeled
• Mode Shape plots with natural frequency, synchronous critical speed(s), stability parameter, and whirl direction
• Rotor Displacements, Dynamic Loads, and Response Shapes.
• Response plots are created in fixed X-Y and rotating Major/Minor coordinate systems
• Amplification factors (AF) automatically calculated
• AF displayed on X-Y response plots with corresponding peak frequency response
• User defined rub limits displayed on Major/Minor response plots
• Separation margins relative to a user defined operating range are automatically displayed
• Plot responses from different rotor stations and/or different analysis runs on same plot
• Animation program included to illustrate rotor modes amd response shapes