Determination of definitions of uninstalled reinforced concrete beams at repeat loads

Abstract

According to the current design rules for reinforced concrete structures, the total deflection of the bending elements is defined as the sum of the deflection caused by the shear deformations, and the deflection caused by the deflections of the bending, taking into account the total curvature of the element in cross section from full load. For bending elements of long length, the deflection caused by shear deformations can be neglected. The curvature of the elements is determined by taking into account the coefficient that takes into account the work of loose concrete in the areas with cracks. The purpose of this work is to improve the method of determining deflections of non-intersecting beams at repeated short-term loads taking into account the change of modulus of elastic plasticity of concrete. When determining deflections of non-intersecting beams at repeated loads, it is necessary to take into account the change in the length of the sign of the bending moment, the transverse force, the curvature of the axis of the beam and changes in the modulus of elasticity of the concrete due to repeated loads. Standards recommend that statically indeterminate designs be calculated taking into account the redistribution of effort. Since the plot of moments and transverse forces from a single load are linear, then the method of calculation of deflections can be used method Vereshchagin AN, breaking the beam into areas within which the stiffness is taken as average. The modulus of elasticity of concrete is determined by its change due to repeated loads. The advanced technique of determination of deflections of non-cutting beams from bending and shear deformations takes into account the change of elastic-plastic characteristics of concrete due to the action of repeated loads. The developed flowcharts can be used to determine the deflections of non-intersecting beams under the action of repeated loads.