This paper deals with new analytical modeling of the classic tensile test with an axisymmetric sample and determining the yield stress of elasto-plastic materials under the neck formation. Known for many years. classical Bridgman and Siebel-Davidenkov-Spiridonov's formulas provide certain errors, especially visible in the case of weakly hardening or ideal-plastic materials. Accurate numericaly simulations of the process allowed verification of the analytical results. Based on the numerical simulations, some modifications of the analytical models and their derivation have been proposed which enabled the elimination of the two most questionable classic assumptions. Comparison of new results with well-known formulas shows that some progress is reached for small plastic deformations; however for greater strain level further improvement is still advisable.
|Number of pages||2|
|Publication status||Published - 2007|