Universal Analytical Dependence of Deformation-Strength Properties of Reinforcing Steels Under Force Tension

Abstract

The article deals with topical issues of the normative methodology for calculating bending and eccentrically compressed reinforced concrete elements along normal sections. They are based on the joint use of a nonlinear deformation model, the hypothesis of flat sections, physically and geometrically linear diagrams of the mechanical state of reinforcing steels of various strengths under force tension. Attention is drawn to the significant inaccuracies of calculations when using the approximate rectilinear steel deformation modulus of constant value E = 2 105 MPa up to the steel's ultimate strength. The high degree of complexity of manual calculation is confirmed when using the actual values of the physically nonlinear steel deformation modulus, approximated by analytical dependences of high degrees. A new author's approach is presented for solving such problems by approximating the real nonlinear strain modulus to the secant strain modulus E's with simple equations for high-strength “hard” and “soft” (not high and medium strength) steels, which allows to manually calculate such problems with greater accuracy.