The Effect of Specimen Dimensions on Obtained Tensile Properties of Sheet Metals

Abstract

A pilot study has been carried out to examine the effect of specimen dimensions on the obtained tensile properties of aluminium and steel sheet. The materials used were DP600 grade steel and AA5754 grade aluminium sheet. Four types of dog-bone samples with varying dimensions were tested for both materials. Standard tensile test procedures were performed using a universal test machine together with contacting extensometry. The GOM Aramis photogrammetric 2D strain mapping technique was also applied. The results suggest that for both steel and aluminium sheet materials, differing specimen dimensions have little effect on the obtained mechanical properties. Depending on the gauge length of extensometer chosen and the position at where necking occurred on the sample, the extensometry results and 2D strain mapping results slightly differed towards to the end of stress-strain curve. The failure mode between the chosen grades of steel and aluminium samples was observed to differ, as did the percentage of failures that occurred within the gauge length. All steel samples fractured across the specimen perpendicularly to the test direction; whilst fracture of aluminium samples occurred approximately 30 degrees from the perpendicular.

On Ausferrite Produced in Thin Sections: Stability Assessment through Round and Flat Tensile Specimen Testing

“…The flow curves matched up to the uniform elongation, that is, when the UTS was reached, and when localized deformation beyond uniform deformation occurred, there were significant deviations with major elongation reduction in the flat specimen flow curve. Different works [62,63] on the effects of flat tensile specimen geometry on mechanical properties have reported that the tensile flow curves were comparable to UTS as long as tensile specimen geometry complied with international standards. In [64], flow curves from round and flat specimens of a ferritic-pearlitic steel have reported the same results found in nickel in Figure 22, with good matching of the tensile flow curves up to UTS and significant deviation after localized deformation.…”