Failure behavior of elbow pipe with local wall thinning

Abstract

Monotonic bending tests were conducted using elbow pipe specimens with local wall thinning. The local wall thinning was machined on the inside of pipes in order to simulate erosion⁄corrosion metal loss. Eroded areas were located in three different areas: called extrados, crown and intrados. Effects of the local wall thinning on the failure behaviors of the elbow pipes were evaluated in terms of the plastic collapse moment. The type of failure for all pipes could be classified as ovalization. Crack initiation were not observed.
Three-dimensional elasto-plastic analyses were also carried out using the finite element method, which could accurately simulate failure behaviors.