Issue 57

K. Benyahi et alii, Frattura ed Integrità Strutturale, 57 (2021) 195-222; DOI: 10.3221/IGF-ESIS.57.16 ௣ : Is Young's modulus at the origin, ௣௘௚ ∶ Is the conventional elastic limit at 0.1%, 0,9 . ௣௘௚ : Is constraint or stops the linear diagram, 1,06 . ௣௘௚ : Is the breaking stress, ε ୱ୳ : Failure strain, ௘ : Steel yield strain, ௘ ∶ Steel yield stress, ௨ : Steel ultimate strain, E ୟ ∶ Steel modulus at the origin, ε ୶ ∶ Gravity center strain, ௕௧௥ : Number of concrete trapezes, ௦ : Number of passive reinforcing beds, ௔௜ : Passive steel bed area, ௔௜ : Passive steel bed dimension relative to the oy reference axis, y ୧ : Lower trapezoidal ordinate, y ୧ାଵ : Upper trapezoid ordinate, b ୧ : The lower abscissa of trapezoid along the x axis, b ୧ାଵ : The upper abscissa of trapezoid along the x axis, Fk and Fk1 : The normal forces acting on layer k in both sections, Gk-1 and Gk : The resulting sliding forces on the lower and upper faces of the k layer, Vk : The share of the shear force balanced by the layer k, m : The number of layers of concrete, : Basic random vector, G : Failure function or limit state function, Φ : The normal law distribution function reduced centered (mean 0 and standard deviation 1), m ୖ : Means strength, m ୗ : Means loads, σ ୖ

: Standard deviations of the strength, σ ୗ : Standard deviations of the loads, P ∗ : Point of the most probable failure, ∗ : Design point, ∗ : Reliability index associated with the design point, , ௎ : Failure function in U space, α ሺ୩ሻ : Vector cosine directors, : Reliability index associated with ி , ி : Probability of failure. R EFERENCES

[1] Collins, M.P. (1978). Towards a Rational Theory for RC Members in Shear, J. Struct. Div., 104(4), pp. 649–666. [2] Vecchio, F.J., Collins, M.P. (1982). The response of reinforced concrete to in-plane shear and normal stresses. University of Toronto, Department of Civil Engineering, Publication No.82–03. [3] Vecchio, F.J., Collins, M.P. (1986). The modified compression-field theory for reinforced concrete elements subjected to shear, ACI Struct. J., 83(2), pp. 219–231. [4] Bažant, Z.P., Kazemi, M.T. (1991). Size effect on diagonal shear failure of beams without stirrups, ACI Struct. J., 88(3), pp. 268–276. [5] Bentz, E.C., Vecchio, F.J., Collins, M.P. (2006). Simplified modified compression field theory for calculating shear strength of reinforced concrete elements, ACI Struct. J., 103(4), pp. 614–624. [6] Carbone, V.I., Giordano, L., Mancini, G. (2001). Design of RC membrane elements, Struct. Concr., 2(4), pp. 213–223. [7] Hsu, TTC., Zhang, L. (1997). Nonlinear analysis of membrane elements by fixed-angle softened-truss model, ACI Struct. J., 94(5), pp. 483–491.

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