A New Approach to Plasticity and Its Application to Blunt Two Dimensional Indenters

The classical slip line field solution for a two-dimensional punch is found to give a constraint factor (2.57) which i s too small when the specimen beneath the punch is extensive. A new approach based on elasticity provides a constraint factor of 2.75. The new method of analysis also enables residual stresses to be estimated and indicates that plastic $ow occurs not only when the specimen i s loaded, but also when i t i s unloaded. Several details concertzing the performance of hardness indenters are explained by the new theory for the first time.