薄肉超小型試験片の単軸駆動式二軸引張試験方法の開発

Abstract

We have established a biaxial tensile test method suitable for the measurement of the local plastic deformation characteristics of a hard aluminum alloy sheet 3104-H, which is a typical material for aluminum can bodies, as a representative of the low work hardening materials. The present method consists of the following: (1) a microminiature cruciform specimen, (2) a newly designed linkage mechanism mounted on a uniaxial tensile testing machine, and (3) the loading path diagram as an experimental method to measure the biaxial stress–strain curves accurately from the biaxial tensile tests with linear displacement paths of the chucking jigs. The following are drawn from the biaxial tensile tests for the thin test material: (i) using the proposed biaxial tensile testing apparatus, we measured a contours of plastic work, and it was in good agreement with that measured using the conventional linear stress path tests, (ii) we were successful to determine the real yield points for various biaxial tensile states using the loading path diagrams and to measure the contour of plastic work corresponding to the maximum equivalent plastic strain of 0.0012, and (iii) the contour of plastic work is well approximated using the Yld2000-2d yield function with an exponent of 7.78.