Experiments on buckling behavior of thin-walled steel pipes subjected to axial compression and external pressure

Pipelines are exposed to various forces in order to develop relative compressive axial and external pressure load in some cases of fluid transmission. An experimental study was conducted to investigate the buckling behavior of thin-walled steel pipes when subjected to a combination of axial compression preloading and external pressure. In addition, the response of some specimens was separately investigated subjected to pure external pressure and axial compression load. A significant reduction was observed in the buckling load and the post-buckling capacity of the thin-walled pipes with increasing the value of axial compression preloading. The existing analytical models for predicting the buckling load of the pipelines were modified. The numerical models were developed and verified using the experimental results, and interaction between the axial load and external pressure was graphically demonstrated for different geometrical ratios. • The buckling external pressure decreased with axial pre-compression. • The elastic limit decreases with increase of axial pre-compression and D/t ratio. • The geometric imperfection pattern could influence local buckling. • The peripheral strain was developed by axial compression and external pressure.