Study of the yield point of the thread

In this work the study of yield point of thread and stress in flow point is shown. The determination of this point is done with the well‐known Meredith’s and Coplan’s construction, which has the basis in tangent method and numerical method, which is developed from sufficient smooth approximation of the curve. The approximation polynomial expression of the ninth order was chosen for the construction of the mean curve σ ( ε ) which, as the sufficiently smooth curve, fits the measured values.