Identification of rheological parameters on the basis of plane strain compression tests on specimens of various initial dimensions

The work is based on the assumption that the flow stress of a material should be insensitive to the method of plastometric testing or to the size of the samples. It is generally observed, however, that various methods of testing yield different values of the flow stress. Endeavours are made to eliminate these differences and various methods of correction of the results of the tests have been developed. The particular objective of the present work is to check the capabilities of the inverse technique to obtain consistent flow stress data when this technique is applied to plane strain compression tests performed on one material with various dimensions of the specimens. The experiments included plane strain compression for specimens measuring 2.5, 5 and 10 mm initial thickness. The inverse algorithm developed by the authors was used in the investigation. Application of the inverse analysis to the interpretation of the results of these tests allowed the conclusion that the results obtained for various specimen geometries coincide very closely.This analysis has been further used for evaluation of various conventional methods for correction to account for the influence of inhomogeneity of strain and temperature.