An experimentally-determined slip-line field for plane-strain wedge indentation of a strain-hardening material

Abstract PRINTED grids are used to measure the plastic flow in very slow speed plane-strain wedge indentation experiments. Using a radial grid with its centre coinciding with the origin of the indentation it is shown that the necessary condition for the maintenance of geometric similarity during indentation, namely that all elements initially on a given radial line should describe the same trajectory in the unit diagram, is satisfied within experimental accuracy over a wide range of indentation depths. A slip-line field is then constructed using the directions of maximum shear strain increment calculated by making an incremental indentation of an initially square grid printed on a previously-indented specimen. In making a stress analysis of this field it is shown that consistent results can only be obtained if account is taken in the stress equilibrium equations of variations in flow stress with strain.