: Determining the RPMs at which a system might experience resonance. Bearing and Seal Performance
| Feature | Specification | |---------|----------------| | Crack model | Breathing + Thermal stiffness decay | | Outputs | 1X/2X amplitude trend, orbit precession, FFT, Campbell diagram with crack | | Temperature range | Up to 1200°C (material dependent) | | Integration | Standalone or linked with Dyrobes unbalance & bearing analysis |
To simulate a crack in a standard linear frequency-domain run, the structural cross-section at the crack's precise finite element station is modified. The engineer calculates the drop in bending moment inertia caused by the crack depth and inserts a short element with a to match that diminished stiffness. 2. Non-Linear Time Transient Analysis
A cracked or thermally warped shaft will demonstrate shifted critical speed peaks and highly distorted, elliptical orbit shapes. Observing these trends in the post-processor helps plant engineers recognize the signs of a developing hot crack from real-time proximity probe data. Core Mitigations for Industrial Hot Cracking dyrobes hot crack
Identifies the decrease in natural frequency.
A "crack" in rotordynamics significantly alters the system's local flexibility and vibration signature. ScienceDirect.com Stiffness Reduction
Limit thermal ramp rates; implement stringent run-out tolerances for the rotor shaft. : Determining the RPMs at which a system
While the phrase "hot crack" is sometimes used in the field to describe the sudden contact (cracking) of seals or the development of a rotor bow, the technical phenomenon is best understood as or Thermal Growth misalignment .
Evaluate crack depth severity by running non-linear parametric sweeps in the software.
Navigate to Analysis -> Lateral Vibration -> Critical Speed Analysis . Compare the baseline healthy rotor's mode shapes against the modified, cracked model. Core Mitigations for Industrial Hot Cracking Identifies the
A hot crack driven by friction or localized thermal bowing displays massive amplitude and phase angle changes during thermal transient states. The orbital path of the shaft centerline—modeled via elliptical and total orbit analysis—stretches, shifts, and loses its circular symmetry, tilting along the axis of the weakest cross-sectional stiffness. Simulating Rotor Cracks in Dyrobes
: Excessive heat in fluid-film or tilting-pad bearings (often analyzed via the DyRoBeS-BePerf