Development of LIFEX principles for high temperature components by means of damage mechanics approach

Continuum damage theory has proven to be an effective tool in creep life prediction. In order to establish some mechanics principles for life extension (LIFEX) of components at elevated temperature, a numerical scheme based on creep damage theory is introduced. To illustrate the strength potential of structures for life extension, the method is applied to some typical structures of geometrical discontinuity, material discontinuity and temperature inhomogenity. Comparisons with actual observations are also given. In terms of the damage distribution or life exhaustion in the structures, some mechanics principles for life extension are proposed.