Buckling of Cracked Cylindrical Shells With Internal Pressure Subjected to an Axial Load

Cylindrical shells constitute the main structural component in pressure vessels and pipelines. Buckling is one of the main failure considerations when designing these cylindrical shells. Defects such as cracks may develop during manufacturing or service life of these structures. These defects can severely affect their buckling behavior due to high stress field generated around these defects. Finite Element Analyses are performed to study the buckling behavior of cylindrical shells with and without a crack, under various internal pressures. Effects of crack length and its orientation on the buckling loads of cylindrical shells having a through or a thumbnail crack are studied. The results show that the buckling loads are not significantly affected for cylindrical shells with a crack less than a critical length. However, longer cracks cause local buckling of the cracked shells and can severely affect their buckling loads. This critical crack length depends on the crack orientation and the shell internal pressure. The results indicate that the buckling loads of cracked shells with internal pressure are quite sensitive to the crack angle. For cylindrical shells with an axial crack, the first buckling load drastically reduces with increasing the shell internal pressure. In contrast, the buckling load increases with the shell internal pressure for circumferentially cracked shells. The buckling loads of cracked shells with internal pressure are quite sensitive to crack angle. However, the bucking loads are little dependent to the crack angle for shells with no internal pressure.