Effect of gripping system on the measured upper yield strength estimated by tensile tests

This paper deals with the effect of the improper engagement of tensile test specimens on upper yield strength. Cold rolled and annealed low carbon steel specimens were tested by a new inhouse gripping system in order to estimate the consequences of improper alignment of tensile specimen. Upper yield strength is extremely sensitive to the eccentricity between the force application axis and the axis of symmetry of the test piece. This sensitivity is characterized numerically by precisely performed laboratory tests.

► A newly developed gripping system for tensile testing is presented.
► This gripping system reduce the specimen alignment errors.
► It is possible to estimate with a higher precision the upper yield strength.
► An experimental method has been presented to estimating the upper yield strength.
► Two novel materials testing parameters have been defined.