Abstract:
This thesis develops a computer program based on API RP 579 for evaluation of a cylindrical component containing a longitudinal-semi-elliptical surface crack subjected to primary and secondary stresses. The program can analyze the primary stress in the form of the internal pressure or the 4th order polynomial function of stress distribution along the thickness. The program can analyze the thermal stress due to 4th order polynomial function of the temperature profile along the thickness and the uniform residual stress profile along the welds width. The program can perform the integrity, the remaining life and the leak-before-beak assessments. In case of the integrity assessment, the program can perform Level 1, Level 2 and Level 3 (Option B). In case of the remaining life assessment, the program can analyze the crack growth due to fluctuating internal pressure with constant amplitude using the Walkers model. Furthermore, the program can characterize the maximum of 2 cracks. The program adopted the weight function method for calculation the crack tip parameter. The program is developed using Delphi 7. The structure of the program is developed based on the object-oriented programming concept and uses the Player-Role pattern to design class diagram. Therefore, the structure of the program is flexible. Validation the program is divided into 2 parts. First, the calculation results from the program are validated with the example in API RP 579. Second, the program is applied to several practical problems. It is found that the program works correctly and the results are consistent with a physical observation.