An approach to turbine housing validation through the measurement of residual strains using neutron diffraction and operationally induced strains using high temperature strain gauges

In order to fully understand turbine housing behaviour it is necessary to appreciate the complex behaviour of the strains within the turbine housing both prior to and during operation. In this paper neutron diffraction techniques have been used to measure surface and internal strains in the turbine housing prior to operation (residual strains) in an area prone to fatigue crack initiation, while high temperature strain gauges have been used to measure surface induced strains due to thermal cycling on gas stand test. Service strain measurements have been compared with simulation results. The direction and magnitude of the measured residual strain is explored in relation to the effect on fatigue crack initiation/ propagation.