Stress–strain state of double-hinged reinforced concrete frames with artificial force regulation under repeated low-cycle loading

The paper presents the results of an experimental study on the behavior of double-hinged reinforced concrete frames with artificial force regulation subjected to single and repeated low-cycle loading. Low-cycle loading has a significant influence on the stress–strain state of U-shaped reinforced concrete frames with artificial force regulation. Under such loading, total and residual deformations of concrete and reinforcement, deflections, and crack widths in frame elements increase. It was found that total deformations in both concrete and reinforcement stabilize by the sixth loading cycle. The bearing capacity of a double-hinged reinforced concrete frame with artificial force regulation exceeds that of a similar frame without force regulation by 5.3% under single loading and by 20.3% under repeated loading. In addition, the deflection of the frame crossbar is reduced by 16.1% under single loading and by 11.2% under repeated loading compared to frames without artificial force regulation.