Numerical characterisation of a cylinder with circumferential cracks under pressurised thermal shock

Abstract

A numerical modelling of pressurised thermal shock (PTS) accidents has been performed. Crack growth and crack arrest are numerically simulated using the finite-element method. The analysis is done in two steps. In the first the observed crack growth phenomena has been used as input to compute parameters such as crack mouth opening displacement, J-integral, stress intensity factor, etc. These parameters are compared with the experimentally observed values and also with the values obtained through numerical investigations by other organisations. Crack growth and crack arrest behaviour are compared with the triaxiality parameter of the state of stress at that moment. The observed crack growth phenomena is plotted on an R-6 diagram to assess the importance of the failure assessment diagram in the evaluation of the integrity of the structure. Effort has also been directed towards studying crack growth using crack tip opening displacement criteria. In the second step, crack growth and arrest conditions have been numerically predicted using the material fracture toughness properties and compared with the experimentally observed data.