Integrity Analysis / Assesment

Remanant Life Assesment

Life prediction and management of cracked high temperature structures is a matter of great importance for both economical and safe reasons. To implement such a task, many fields such as material science, structure engineering and mechanics science etc. are involved and expertise is generally required. In terms of the methodology of advanced time-dependent fracture mechanics, this paper developed an expert system to realize an appropriate combination of material database, condition database and knowledge database. Many assessment criteria including the multi-defects interaction and combination, invalidation criterion and creep-fatigue interaction are employed in the inference engine of expert system. The over-conservativeness of life prediction from traditional method is reduced reasonably and therefore the accuracy of predicted life is improved. Consequently, the intelligent and expert life management of cracked high temperature structures is realized which provides a powerful tool in practice.

During the mandatory inspection activities, termed as REMNANT LIFE ASSESSMENT STUDY ( RLA Study) , following major activities are undertaken:

  • Study of operation and maintenance (O&M) records.
  • Visual inspection
  • Structural Integrity (By NDT & dimensional measurement)
  • Verification of mechanical properties and analysis of results.
  • Material degradation due to transformation of micro structure.
  • Impact of Chemical regime during operation

To accomplish, Remnant life assessment study, a multiple disciplinary team needs to be deployed to collect (O&M) data , NDT results , destructive test results from laboratory and analyze them to offer conclusive recommendations.