2. Worked as a Research Associate on a research contract in
Mappin Street, Sheffield S13JD,
A View of Administrative
Period: August 1987 to Dec. 1989
Investigation into the Stresses associated with Compressor
Project Supervisors :
This is a collaborative
research project between Rolls-Royce plc,
Typical Rolls Royce Engine:
The experimental stress analysis technique of photoelasticity is one of the most versatile methods available which enables both boundary and internal stresses to be determined.
The ultimate aim of the project is to investigate using detailed photoelastic analysis, the stress distributions around the fillet and contact zones of the fir-tree root type of blade fixing. Previous theoretical and photoelastic stress analyses of these fixings indicate that a maximum stress occurs in the root fillet radius but away from the contact zone. Failure evidence however shows that some cracks initiate from sites within the contact zone. The major aim of the project is to analyze the effect
of various parameters such as tooth geometry, load distribution along the flanks, and the frictional effects due to the relative motion between the teeth, on the stresses found in the fillet regions and the contact zones.
Extensive photoelastic investigations on simplified two-dimensional blade models with different flank angles (0°, 30° and 45°) and contact conditions were conducted. It was followed by a series of studies on the slices cut from a three dimensional stress-frozen bladed-disk photoelastic model (slices were supplied by Rolls Royce). A slice analyzer with high optical resolution was used in these investigations.
Typical results of the investigations are presented below:
Analysis on three-dimensional stress frozen model (Slice Analysis):
1. Kenny, B., Patterson, E. A., Said, M., Aradhya, K. S. S., 'Contact stress distributions in a turbine disc dovetail type joint - a comparison of photoelastic and finite element results', Strain, 27(1): 21 - 24.
2. B. Kenney, E.A. Patterson and K. S. S. Aradhya, 'Photoelastic analysis of dovetail joints for turbine blades', Proc., Conference on Applied Stress Analysis held at the University of Nottingham, Nottingham, N67 2RD, ENGLAND, during August 30-31, 1990.