DETERMINATION OF DYNAMIC FORCES IN COMPLEXLY STRESSED ELEMENTS OF REINFORCED CONCRETE FRAMES UNDER SPECIAL IMPACT

Abstract

On an energy basis, without involving the apparatus of dynamics of
 structures, an analytical solution of the problem was obtained to determine the dynamic
 additional loads in complexly stressed reinforced concrete elements of multi-storey frames
 in a transcendental state caused by special emergency effects. The stress state, crack
 patterns and fracture patterns in the crossbars of the considered frame structures are
 determined by the complex stress state of the frame elements caused by the combined action
 of torsional and bending moments. The assessment of the bearing capacity of such
 structures was carried out by the diagram method based on the use of energy ratios in the
 structural elements before and after a special impact, which makes it possible to determine
 the maximum dynamic deformations, curvatures and forces in the first half-wave of
 vibrations using the results of nonlinear static calculations according to the primary and
 secondary design schemes.