Evaluation of barreling and friction in uniaxial compression test: A kinematic analysis

Barreling compression test is an important tool for characterizing the mechanical responses of deformed material. This test also serves for studying the interfacial friction between the tool and workpiece, based on the only available method of Avitzur's limit analysis of disc and strip forging. This method was found to be satisfactory for low friction conditions; however, it has remained to be examined in depth. In the present work, Avitzur model is thoroughly investigated, and its applicability and limitations are discussed. Along these lines, the kinematics of Avitzur model are presented to be used in describing both the barreling parameter of the model and the profile of the deformed sample. Following an exhaustive examination on the barreling parameters of various deformed samples, one of the methods is identified to be valid for evaluating friction factor up to m <= 0.5. Moreover, the results clearly show that the model has its highest accuracy as long as the side-surface folding phenomenon is negligible (<= 0.25%).