Plastic collapse loads in shape-imperfect pipe bends under in-plane opening bending moment

Application of failure assessment diagram methods to cracked straight pipes and elbows

“…Usually the elbow cross-section is considered to be circular with uniform wall thickness. In practice, according to [14,15,16,17] the elbow cross-section M A N U S C R I P T…”

Determination of collapse loads in pipe bends with ovality and variable wall thickness under internal pressure and in-plane opening moment

“…An equation to determine collapse load of pipe bends with ovality under in-plane opening moment has already been proposed [15] for r/t ¼ 10, 15 and 20. This equation has been slightly modified and presented below as r/t ¼ 5, 10 and 15 for the present study.…”

“…Christo Michael et al [13] compared the limit based on small displacement analysis and collapse loads based on large displacement analysis of pipe bends with ovality and thinning under combined internal pressure and in-plane closing moment and concluded that the determination of collapse load is suitable rather than limit load when ovality is present in pipe bends. Buckshumiyan et al [15] determined collapse load of pipe bends with ovality when the bends are subjected to in-plane opening moment and found that the effect of ovality is significant and proposed a mathematical expression to include the effect of ovality in the determination of collapse load of pipe bends. The present work determines the effect of ovality and thinning on collapse loads of pipe bends subjected to in-plane bending and internal pressure loads.…”

Determination of ovality and wall thinning effects on B2 stress indices for pipe bends under in-plane closing bending moment

“…[13][14][15] Buckshumiyan et al investigated the effect of ovality and thinning on plastic collapsing loads under a combination of internal pressure and in-plane opening bending and derived equations for the critical limit and critical collapsing loads of bends under in-plane opening bending moment. 16,17 Matzen and Tan presented a series of comprehensive studies on calculation of normalized B 2 stress indices for piping components by using nonlinear FE analysis. 18 Schau et al studied the influence of ovality and nonlinearities on the failure mode and B 2 stress index of thin-walled straight pipes by using FE analysis.…”