Nonlinear delamination analysis of mulyilayered functionally graded circular shafts in torsion

Cylindrical delamination in a multilayered functionally graded circular shaft loaded in torsion is analyzed assuming a nonlinear mechanical behaviour of the material by using the Ramberg–Osgood equation. The shaft is made of an arbitrary number of adhesively bonded concentric layers of different thicknesses and material properties. In each layer, the material is functionally graded in both radial and longitudinal directions. A solution for the strain energy release rate is derived by analyzing the energy balance. The solution is used to perform parametric investigations of the delamination behaviour.