Uncertainties of the critical buckling pressure of a tube

Collapse of a tube is considered in this work. The conservatism of the elastic buckling formula is concerned in particular. It is analyzed using the formula of critical buckling pressure, which consists of the parameters such as the elastic modulus, Poisson's ratio, thickness and radius of a tube. The uncertainty of each parameter is investigated and assessed. In addition, an oval shape of the tube cross section is also considered to incorporate the initial irregular shape possibly observed. As a result, the thickness uncertainty caused by the dimension tolerance is the most influential to overestimate the critical buckling pressure. Moreover, the ovality of a tube is found more critical than the thickness uncertainty in the prediction of the buckling failure. An example guideline of a tube thickness avoiding the buckling failure is presented accommodating the uncertainties and ovality.