Description of the Expansion of a Two-Layer Tube: An Analytic Plane-Strain Solution for Arbitrary Pressure-Independent Yield Criterion and Hardening Law

The main objective of the present paper is to provide a simple analytical solution for describing expansion two-layer tube under plane-strain conditions its subsequent use in preliminary design hydroforming processes. Each layer’s constitutive equations are an arbitrary pressure-independent yield criterion, associated plastic flow rule, and hardening law. elastic portion strain neglected. method based on two transformations space variables. Firstly, Lagrangian coordinate introduced instead Eulerian radial coordinate. Then, replaced with equivalent strain. reduces ordinary integrals that, general, should be evaluated numerically. However, laws practical importance, these expressed terms special functions. Three geometric parameters initial configuration, parameter, functions classify boundary value problem. Therefore, detailed parametric analysis not feasible. illustrative example demonstrates effect outer thickness pressure applied inner radius tube.