Pre-test thermo-mechanical analyses using finite element method were carried out on four numbers of cruciform type specimens designed to simulate pressurized thermal shock (PTS) event in Reactor Pressure Vessel of PWR type reactors. The cruciform specimens were designed to produce different biaxial stress ratios 1:0, 1:1 and 2:1. Sequentially coupled thermal mechanical analysis approach was used to analyze the specimens. Biaxial mechanical stresses were produced in the core of the cruciform type specimen by subjecting the specimens to bending load and thermal stresses were produced in the specimens by heating the core of specimen to 300°C and then cooling it by spraying water. Various fracture mechanics parameters such as J-integral, crack mouth opening displacement (CMOD) and load line displacement (LLD) were evaluated. It is found that crack driving force (J-integral) increases during the thermal transient and crack growth is predicted in some of the specimens.
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