Suitability of assumed cross sections to include ovality in the limit analysis of pipe bends under in-plane closing moment and internal pressure

To include ovality in the analysis of pipe bends, elliptic and semi-oval cross sections are generally assumed. This study determines collapse load equations for semi-oval cross section using finite element analysis under in-plane bending and internal pressure and compares them with the existing collapse loads for elliptic cross sections. The comparison reveals that elliptic or semi-oval cross section may be used when the pipe bend is subjected to only in-plane bending moment. With internal pressure, though elliptic cross section is suitable for low pressures, semi-oval cross section may be preferred as it is suitable for high pressures.