Engineering Analysis is the cornerstone of our practice. Whether we are designing new products, engineering enhancements to existing products or evaluating a current design, understanding the fundamental physics of the design as expressed mathematically is our standard. MathCad is our standard tool for equation derivation and analysis and we have integrated it into several of our proprietary programs for analyzing Retaining Rings, Turbo Generators, Salient Pole Generators and Induction motors.
Finite Element Analysis
EME uses advanced finite element techniques in support of both design and failure analysis studies. In addition to typical stress analysis, some of these techniques include:
- Simulation of shrink fits subjected to torque and thermal gradients
- Nonlinear elastic and plastic deformation
- Thermal transients and coupled stress-strain problems
- Determination of stress fields for fracture mechanics analysis
- Modes and Natural Frequencies of Vibration
- Harmonic Response of Structures
- Seismic (Response Spectrum) Analysis, including Safety Related Nuclear Equipment
The use of these techniques requires care and practical knowledge of the subject of the study. EME engineers have the training and experience needed to employ these tools as necessary, and all calculations are backed by analytically-solvable test cases that prove the validity of the results.
Hoop stress in a split Hydro Generator rotor with three shrink fits, bolted connections and shrink links, including effects of rim heating, 100 rpm rotation and field pole magnetic/centrifugual forces.
Heat Transfer and Thermal Analysis
Classical solutions methods such as resistance networks and finite difference modeling as well as Finite Element Analysis are utilized to predict temperature distributions on field and stator windings (hot spots). Complete rotor/stator assemblies can also be analyzed as part of trouble-shooting activities or initial design efforts. Our software is able to model the effects of conductor resistance change with temperature for a better estimate of hot spot temperatures. As well, when using the Finite Element Method, a detailed solution of the structure’s temperatures can be impressed on the stress/strain model to obtain a coupled solution of the mechanical and thermally induced stresses and strains.
EME uses advanced Rotor Dynamics software for both design and diagnostic purposes. Both lateral and torsional studies are performed to support such efforts as collector design or starting a synchronous condenser. This software includes complete hydrodynamic bearing modeling capabilities. The bearing dynamic properties are thus tightly integrated with the lateral critical speed and dynamic response analysis.
Adequate cooling of electrical machines is necessary to ensure performance and service life of the equipment. When elevated temperatures are indicated, a study can be performed to evaluate the ventilation characteristics of the design. The ventilation study combined with a thermal analysis can result in a redesigned ventilation arrangement or augmented ventilation system which produces a dramatic improvement in the temperature distribution across the machine, resulting in improved performance and longer life.
Vibration Testing, Analysis & Troubleshooting
EME utilizes a variety of testing equipment to analyze, test and diagnose vibration issues. Proximity Probes, Siesmi Probes, multi-channel recorders and fast fourier analyzers are employed in determining resonant frequencies, mode shapes, the operating deflection shape for rotor trains as well as the magnitude and phase angle of mass imbalance. Read More >>