Curve-Fitting Functions for Stress-Strain Diagrams of Reinforcing Steels.

For the appropriate use of reinforcing steels for concrete, more particularly in a reliable and predictable way, it is essential to know the stress-strain diagram obtained in the tensile test. The range of incipient plastic deformation is especially important in this context. The object of investigations reported here was to assess the suitability of three curve-fitting mathematical functions for describing the stress-strain diagrams of such steels. In particular, it was necessary to find out how accurately their characteristic values can be numerically determined and whether it is possible to describe reinforcing bars of different types and dimensions with the aid of a uniform set of parameters.