Design and remaining life assessment of vital engine components such as turbine blades, vanes and discs and in critical engineering components such as gas steam pipes, pressure vessels, in thick-section plates and weldments which might contain pre-existing defects need accurate and reliable uniaxial, multiaxial and crack growth material properties data. Recent improvements in non-destructive inspections and crack length measurement methods have allowed smaller and smaller defects to be detected. This has resulted in the increasing acceptance of elevated temperature crack growth initiation and failure analyses as independent and powerful design and remaining life assessment tools. The development of high temperature fracture mechanics concepts, through which time dependent effects of creep cracking could be modeled, invariably use experimental uniaxial and crack growth data from simple Compact Tension laboratory test specimens in order to predict failure times of components under operating conditions. It has also become more evident that industry needs additional justifications and verifications in order to accept, with confidence, the available laboratory experimental data which it uses in their defect assessment codes. It therefore seems appropriate to develop and improve testing methods for pre-cracked non-standard geometries and 'feature' components to improve and validate results from life assessment codes that industry uses for components working under static and cyclic creep and creep/fatigue loading conditions.
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