A Code of Practice has been formulated offering a route for improved life assessment techniques of critical turbine components subjected to complex multiaxial loads.
The Code requires further validation before it could be used comprehensively with confidence. On the other hand it is expected to have improved accuracy over other codes which do not explicitly address multiaxial loading.
Uniaxial and multiaxial materials data have been generated on four important steam and gas turbine materials which has led to an improved understanding of material performance under complex loading conditions relevant to operating experience.
Test techniques and analysis procedures have been developed to enable multiaxial constitutive laws to be established with confidence.
A patent has been submitted on a new triaxial stress testing machine.
A range of candidate algorithms have been developed addressing multiaxial creep and fatigue damage in a range of industrial turbine components that have led to improvements in the capabilities for life assessment for end-users and design considerations for manufacturers.
Laboratory based and in-service field experience validation exercises have been conducted that have established the strengths and weaknesses of the candidate algorithms and highlighted the areas where further validation is required.
Two condition assessment techniques have been developed and partly validated. These can both be incorporated into life assessment routes in order to refine or periodically re-calibrate the calculational based approaches.