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A method of determining flow stress and friction factor using an inverse analaysis in ring compression test

링압축시험에서 역해석을 이용한 유동응력과 마찰상수 결정법

Choi, Y.;Kim, H.K.;Cho, H.Y.;Kim, B.M.;Choi, J.C.
최영;김호관;조해용;김병민;최재찬

  • Published : 1998.03.01

Abstract

An inverse analysis been applied to obtain the flow stress of the material. In this method, a ring-shaped specimen is compressed between two flat tools. This procedure employs, as the object function of inverse analysis, the balance of measured loads and reaction forces calculated by using rigid-plastic finite element method. The balance is explicit scalar function of flow stress which is a function of some unknown constants. For minimizing the balance, Newton-Raphon scheme is used. The friction factor, m, between flat tools and the specimen is determined by using friction area-divided method. The proposed method allows an accurate identification by avoiding the usual assumptions made in order to convert experimental measures into stress-strain relation. In this paper, the proposed method is numerically tested. A commercial pure aluminum was selected, as an example, to apply the method and the results are compared with stress-strain relation obtained by experiments.

Keywords

Inverse Analysis;Flow Stress;Ring Compression Test;Friction Factor