CALCULATION MODEL OF A MULTI-STOREY REINFORCED CONCRETE FRAME WITH COMPLEXLY STRESSED BEAMS UNDER ACCIDENTAL IMPACT

A computational model is presented for determining deformations in complexly stressed beams of a structurally non-linear reinforced concrete frame in a transcendental state caused by a special emergency action in the form of a sudden removal of one of the structural elements. The determination of the stress-strain state after the formation of spatial cracks in the reinforced concrete elements of the frame was carried out using the calculated spatial section. At the same time, dynamic additional loads in the design section of the reinforced concrete frame element from a special impact are determined on an energy basis using the “bending moment-curvature” and “torque-angle of rotation” diagrams. The considered calculation algorithm includes the determination of forces in compressed concrete, longitudinal and transverse reinforcement for primary and secondary design schemes and verification of special limit state criteria. The results of a numerical analysis of the effect of cracking, the ratio of torque and bending moment on the stress state in transverse and longitudinal reinforcement and on the dissipative properties of a frame structural system are presented