Affiliations: Mechanical Engineering Department, Imperial College, London SW7 2BX, UK E-mail: [email protected]
Abstract: In life assessment methodologies, which involve analyzing cracks and discontinuities, there is a need to assess the significance of the defects which may exist in high temperature equipment operating in the creep and creep/fatigue range. Creep and creep/fatigue crack growth models as well as residual defect assessment codes need reliable and verifiable material properties data and validated fracture mechanics parameters for use in their predictive methodologies. Versailles Agreement on Materials and Standards (VAMAS) working group TWA25 has incorporated in a draft Code of Practice the results from the research to develop an overall methodology for deriving acceptable data and validated parameters for life assessment analysis. The pre-standard recommendations in TWA25 have been developed further taking into account the present Creep Crack Growth ASTM E1457 standard. The Draft Code of Practice (CoP) identifies methods of testing and presents validated fracture mechanics parameter used for analyzing laboratory creep crack growth data derived from non-standard feature test components.
Keywords: Creep, fatigue, fracture mechanics, component, crack growth, codes of practice, high temperature, standards