Ultimate Capacity of Pipe Bends Under Bending and Pressure

Abstract

The structural capacity of pressurized pipe elbows under in-plane bending is examined. The investigation is conducted through advanced finite element analysis tools. The numerical results are successfully compared with available experimental measurements. In addition, a parametric study is conducted, which is aimed at investigating the effects of the diameter-to-thickness ratio on the ultimate capacity of 90 deg elbows, focusing on the failure mode (buckling or flattening), the maximum bending strength, and the deformation capacity. The effects of moderate internal and external pressure levels on the ultimate moment and the failure mode are examined extensively.

Validation on large scale tests of a new hardening–softening law for the Barcelona plastic damage model

“…Under extreme loading conditions, such as the high repeated incursions in the nonlinear zone that the imposed displacement in this case causes, elbows exhibit two different failure modes. These are either significant cross-sectional ovalization or local buckling, as reported by the experimental work described in Sobel and Newman [23], [24], Dhalla [25] and Greenstreet [26], Tan et al [27], Shalaby and Younan [28] and Suzuki and Nasu [29] for monotonic bending moments and Yahiaoui et al [30], Slagis [31] and Fujiwaka et al [32] for cyclic loading, and from the work of Karamanos et al [33], [34], Pappa et al [35], Varelis et al [36], [37].…”