抄録
The effects of change in specimen dimension on elongation percentage of an aluminum alloy was investigated for round specimens having various lengths in reduced section and radius of fillet. The specimens were machined from 5052-O alloy plate of 30mm thick. The size of specimens suitable for obtaining tensile characteristics of the material was determined.
The principal results obtained were as follows.
(1) The length of the region of shoulder constraining strain distribution near the end of the reduced section was nearly equal to the length of the diameter of reduced section (when measured from the end of the straight section) independent of fillet radius.
(2) It was desirable that the length of the reduced section of round specimens, Lc, would be determined by the following formula: Lc≥L0+2D (in which L0: gauge length, D: diameter of the specimen) for eliminating the effect of shoulder fillet radius on the elongation percentage obtained by tension tests.
(3) The length of the neck, which had previously been measured along the specimen before the test, was 23D for the materialused.
(4) It was desirable that the full length of neck remained within the gauge length when rupture occurred around the center of the specimen. Accordingly, the length of the reduced section of round specimens would preferably be in the range of Lc≥5.5D.
