Comparison of tensile properties between round and rectangular specimens

Abstract

These investigations were undertaken concerning the effects of shapes of round and rectangular specimens on the tensile properties of aluminum alloys.The specimens were machined from 30mm thick plate of an aluminum alloy designated as 5052-O.The principal results obtained were as follows:(1) The size and shape of test specimens had practically no effects on the proof stress and tensile strength of the material.(2) The curve representing the relation between δ and L0/√A (in whichδ: elongation percentage, L0: gaug elength, and A: cross-sectional area of the specimen) of round specimens was virtually identical with that obtained from rectangular specimens having nearly the same width as thickness. However, it was found that δ for the same value of L0/√A was slightly decreased with the increase in the ratio of width to thickness in rectangular specimens.(3) When L0/√A≥10, the values of δ were little different between round and rectangular specimens independent of their sizes and shapes.(4) In round specimens, the region of shoulder constraining the strain distribution near the end of the reduced section (lf) was nealy equal to the length of the diameter from the end of the straight section.In rectangular specimens, the value of lf/W (W: width of the specimen) was increased with the decrease in the ratio of width to thickness, and it was approximately equal to 1 in square cross-sectional specimens.(5) The reduction of area in the fracture section was slightly descreased with the increase in the ratio of width to thickness in specimens of rectangular section, but it was nearly constant in round specimens of different diameters. There was very little difference of the value between round and square cross-sectional specimens.