Variability of strength and stiffness assessment for non-profile beam structures

Introduction . Traditional ways to increase the structural strength and stiffness of beams are now almost exhausted, and optimization of production and operation technologies is mostly based on the use of new materials and increasing their reliability as bearing elements of a complex geometric profile. Bearing elements of building structures operate under high loads and, even despite their predominantly static nature, experience a complex volumetric stress and strain state, which can scarcely ever be confirmed empirically and statistically. Aim . To propose an approach to assessing the strength and stiffness of beam structures operating under conditions of transverse bending of a complex geometric profile. Materials and methods. Classical energy methods, including Castigliano, Maxwell–Mohr and Vereshchagin methods (moment area method), have been used to assess the strength and stiffness of non-profile beam structures, initial parameters, differential equations of the deflection curve. Results . The similarity parameters (fitting criteria) of Mises–Hencky and Zhurkov reflect the behavior of a brittle or plastic beam material reasonably well. These characteristics are proposed to be combined in the Arrhenius–Zhurkov durability functions. Conclusions . The dependencies given in the calculations can be recommended for improving the flexural static and fatigue strength, as well as the stiffness of the bearing elements of building structures.