PSI - Issue 44

Mauro Mezzina et al. / Procedia Structural Integrity 44 (2023) 566–573 Mauro Mezzina, Alfredo Sollazzo, Giuseppina Uva/ Structural Integrity Procedia 00 (2022) 000–000

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shear actions V i at the base of the panels occurs in the individual element depending on the type of resisting mechanism that is engaged (Fig. 5).

Fig. 4.

Results of the analysis: a) Bredt-like distribution; b) distribution proportional to the panels’ stiffness

Fig. 5 Left: response of a single panel at the i-th floor; right: “Rausch-like” schematization in the case of panel with opening. 4. Overall effects of circulatory torsion In the case of pure torsion, only the tangential stress τ zs is present in the horizontal plane section. Because of the reciprocity of the tangential stresses, the tangential stresses τ sz , the only non-zero stress components, act on the walls of the building. The stress state is plane, and the principal tensile and compressive stresses are equal in absolute value to the τ sz ; the isostatic lines are helical and always inclined at 45° respect to z-axis (Fig. 6).

Fig. 6. a) Stress state in the walls of a building; b) Rausch-like schematization. (T is the torsional stress; ϕ is the flow of tangential stresses; ϕ C is the component of ϕ in the direction of the compressed strut; ϕ L is the component of ϕ in the z-direction; Ω is the area enclosed by the middle line of the horizontal section).