Experimental Sutdaies On Reinforced Circular Tubular's Ultimate Capacity

As one of the most fundamental joint configurations in tubular structures, The ultimate capacity of planer gap tubular K-joints is insufficient sometimes, which limit the project application of steel tube-truss. Therefore the research of reinforced joints has an important theoretical and practical significance. The main goal is to study whether the strengthen method is efficiency to steel circular K-joints, to analysis the design formulae of reinforced circular steel tubular K-joint (RCKJ).The RCKJ experiment is designed by orthogonal design method. And then the specimens can be properly simulated to destroy in ANSYS(FEM soft). Also the ultimate capacity of RCKJ were calculated. However, test is the most important research method of ultimate capacity of tubular joints. It is also the most direct method to confirm the ANSYS simulation test. The number of RCKJ specimen is designed to be twelve with orthogonal design method. The tests on twelve RCKJ, including six reinforced circular steel tubular K-joints with a flashboard and six reinforced circular steel tubular K-joints filled with concrete, is carried out in this dissertation. Then the tests result is compared with results of finite-element analysis and design formula and the difference of them are analyzed.The main influence factors to enhance the ultimate capacity of RCKJ are analyzed in this dissertation. Based on the results, the ultimate capacity formula of RCKJ is summarized by using multiple linear regression analysis.Finally, available references for constituting and consummating of steel tubular design formula are given.