Abstract
This thesis contains the results of a novel combination of experimental measurements and simulation techniques to characterise the stress/strain behaviour throughout a typical lifecycle of a turbine housing. During operation the turbine housing is subjected to thermomechanical fatigue (TMF). The accurate validation of residual stress (both before and after operation) and stresses induced due to applied loading can be challenging and internal residual stresses in areas prone to fatigue crack initiation are difficult to measure accurately.Experimental measurements of residual stress were obtained using two techniques. Neutron diffraction, a non-destructive technique based on the measurement of the shift in atomic lattice spacings induced by stress, was used to measure internally within the turbine housing both before and after the application of thermomechanical load cycles. The contour method, a destructive technique, based on the measurement of deformed surface contours after stress-relief induced by cutting was used to obtain measurements on a turbine housing before thermal cycling. High temperature strain gauges were used to measure strain due to applied thermomechanical load.
Simulations of the residual stresses present in the turbine housing at the end of the production process which included an annealing heat treatment showed very low
| Date of Award | 25 Oct 2019 |
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| Original language | English |
| Supervisor | Susan Kilcoyne (Main Supervisor) |