A validation of the three-dimensional finite element contact method for use with Curvic couplings

Curvic couplings transmit torque between parallel in-line shafts or turbine/compressor discs. They are used extensively within the aero-engine industry but can also be found in industrial gas turbines. The manufacture of Curvic couplings involves the precision cutting and grinding of mating teeth on the adjacent ends of the components; the assembly is then clamped together with bolts. The design objectives for aerospace transmissions, and hence the Curvic coupling, are to reduce manufacturing cost, weight and size. The experimental testing of Curvic couplings within an aero-engine environment is time consuming and expensive. The objective of this paper is to justify confidence in the results from three-dimensional finite element (FE) contact analyses when investigating Curvic couplings. The accuracy of the FE analyses requires a fine mesh in the contact region and the capability to deal with stick-slip behaviour in multiple three-dimensional contact surfaces. A comparison of the results from a photoelastic test with the results from an FE analysis provides a validation of the FE contact method for use with Curvic couplings. The results presented in this paper indicate that the photoelastic results agree reasonably well with results of the FE method analyses.