Experimental Study On Cable-supported And Knee-braced Steel Frame

Based on the cable-supported and knee-braced steel frame, two scale models are designed for the static test under load conditions, including performance test and pre-stressed parameter test. According to the test data, the mechanism of each part, the overall mechanical performance and the influence of cable sectional area and pretension on cable-supported and knee-braced steel frame are studied in this paper. Finally, numerical analysis of test model is carried on by finite element software SAP2000, the correctness of the test and further refinement of the conclusion are verified by comparing with test results.Through the performance test, adverse value of knee-bracing cable pretension to steel frame decreases with the decreasing of knee-bracing cable force and achieves zero, and cable-supporting parts can enhance steel frame mechanical performance under vertical downward load. And adverse value of cable-supporting pretension to steel frame decreases with the decreasing of cable-supporting force and achieves zero, and knee-bracing parts can enhance steel frame mechanical performance under vertical upward load. Under horizontal load to left, cable-supporting parts do not play a role, the influence of left knee-bracing cable pretension to steel frame will be gradually offset with the decrease of cable force, and right knee bracing cable can enhance the steel frame mechanical performance.Compared simulation results with test data, the relationship curve characteristics are in good agreement, but the absolute value of the test data is smaller than simulation results, and the main reason is that a lot of connected components are added at beams and beam-column junctions in test model and these components enhance overall stiffness of frame.By the pre-stressed parameter test, it is found that the increase of cable-supporting pretension increases pushing force, and the increase of knee-bracing pretension increases the drag force for steel frame, but it has no effect on bending moment and deformation growth rate of each section. The bending moment and deformation of the steel frame with different cables are related to cable sectional area and increases according to its change ratio. Each section bending moment and deformation growth rate of cable-supported and knee-braced steel frame declines and there is a peak with the increase of cable sectional area, which corresponds to the most economical cable sectional area. Cable sectional area changing has little impact on each section bending moment and deformation growth rate of steel frame under horizontal load.