Finite Element Analysis of Elbow Ultimate Load under Out-of-plane Bending Moment

The three-dimensional(3D) nonlinear finite element analyses(FEA) was used to have the material simplified into ideal elastoplastic body and have the influence of geometric nonlinearity considered simultaneously;and the elbow's ultimate load which connected with straight pipes under out-of-plane moment with various thickness-diameter ratio(t/Do) and relative bending radius(R/Do) was analyzed,and the out-of-plane plastic limit bending moment equations for defect-free elbows in engineering were found.The experimental data can confirm the practicability of these equations as the engineering practice required.