Chris Cooley
E-mail: cooley.168@osu.edu
Research Area:
My research involves finite element/contact mechanics (FE/CM) modeling and analysis of gear systems. An overview of a few projects I have worked on is given below.
Finite Element/Contact Mechanics Modeling of a Wind Turbine Gearbox
This project involved the modeling and static analysis of a wind turbine gearbox. The simulation modeled two planetary stages and one parallel axis gear stage. Each stage was coupled together through shafts, bearings, and a housing. Models like these allow us to investigate
Simulations also reveal how manufacturing errors and gravity affect load distribution and planet load sharing.
- the tooth contact load distribution over the facewidth of each gear to determine tooth fatigue,
- planet load sharing at each stage for increased bearing life, and
- the design of optimal tooth profile modifications for low noise and vibration.
Finite element/contact mechanics model of a wind turbine gearbox
Finite element/contact mechanics calculation of tooth contact pattern
A Frequency Domain Finite Element Method for Three-Dimensional Gear Dynamics
A frequency domain finite element method was developed to determine the dynamic response of gear pairs. The method uses the static transmission error as excitation to a linear dynamic finite element model. This method benefits from the superior calculation of static transmission error and average mesh stiffness from a combined finite element and semi-analytical formulation. Computation times with the frequency domain method were two orders of magnitude lower as compared to numerically integrated (time domain) finite element results. This formulation admits system level gearbox simulations, which may contain shafts, bearings, and a housing.
Publication
C.G. Cooley, R.G. Parker, S.M. Vijayakar. A Frequency Domain Finite Element Approach for Three-Dimensional Gear Dynamics. Proceedings of the 2009 ASME IDETC/CIE, San Diego, September 2009. Accepted.
Gear pair finite element/contact mechanics model
Frequency domain finite element calculation of gear vibration over a range of gear speeds at high and low torque.
Gear-Shaft Dynamics
The dynamic response of a gear-shaft system is determined using a finite element/contact mechanics formulation. Comparisons of helical and spur gear-shaft systems show additional modes for helical gear-shaft systems. These are additional tilting, bending, and axial motions that occur due to the helix angle causing thrust loading.
Shaft vibration comparison for a spur and helical gear-shaft system
Helical gear-shaft bending mode
Helical gear-shaft bending, axial, torsional mode
Bio:
2006-present: Ph.D. Student, Mechanical Engineering, The Ohio State University
2002-2006: BSME, Western Michigan University, Kalamazoo, MI
