Szacowanie współczynnika tarcia na czołach ściskanej plastycznie próbki walcowej

In this paper the method has been proposed which makes it possible to estimate the coefficient of friction between the interfaces of the plastically deformed cylindrical specimen and loading plates. The method is based on earlier Siebel's simple theoretical analysis of this problem. The relations given by Siebel were reformulated to the proper form enabling us to estimate the coefficient of friction from the series of compression experiments on specimens of different height to diameter ratio. The method proposed can be applied to different height to diameter ratio, also to different stages of deformatation and different conditions of lubrication. In the paper some numerical results are shown which have been obtained on the basis of the compression experiments on aluminium. In addition, some numerical results are shown for copper, based on earlier results given in literature. The present analysis takes into account the effect of inaccurate determination of the yield limit on the coefficient of friction, in the model of a perfectly plastic body assumed in the considerations. The results obtained in this way are compared with the proper data taken from the different sources and obtained by different methods. It may be stated taht the proposed method can be applied to the practical cases of static compression as well as to the dynamic compression experiments.