Experimental Investigations On Static Behavior Of Gapped K-type Rhs Joints With Chord Plate Reinforcement

Hollow Section Structures(HSS) have been used in many long-span structures and high-rise structures because of their advantages. For the HSS, the capacity of the joint is significant. However, there may be some problems that the joints’ strength is insufficient. In this case, it’s necessary for the joints to be reinforced. It’s effective to strengthen the joint with doubler plates. The research of the joints reinforced with doubler plates has been more and more perfect. However, there is deficient research on the gapped K-type RHS joints reinforced with doubler plate, especially in the field of experimental investigations. In this paper, static behavior of gapped K-type RHS joints with chord reinforced with doubler plate would be conducted. The following is the concrete content of this paper:At the first, static tests on six joints with chord reinforced with doubler plate and one joint without reinforcement have been carried out in this paper. In these tests, the length and the width of the doubler plate were chosen as test variables. The phenomenon of the specimens was recorded and the failure modes were summarized.The static strength of the specimens was determined through processing the initial testing data. The influence of the variables on the static strength of the joints and the degree of improvement of the static strength from joints reinforced to joints without reinforcement was discussed.In the next place, finite element(FE) model has been established to simulate the specimens on the basis of the tests and the boundary conditions, loading mode,geometric parameters, material properties were as same as the real testing specimens.By comparing the testing results and the numerical results and analyzing the causes of the deviation, the accuracy and rationality of the FE model would be confirmed.Furthermore, the testing and numerical results and the results calculated by the formula were compared. The causes of the deviation and the factors which could influence the results of the formula were analyzed. And then, the formula was revised reasonably.At last, studies about the ratio of the static strength of the joints to the static strength of brace were carried out. The influence of the geometric parameters of the chord and the brace on the ratio of the static strength of the joints to the static strengthof brace was discussed. Problems that how to choose the thickness of the doubler plate on the premise that the static strength of the joints is not less than the static strength of the brace was considered. At last, the suggestions of how to choose the thickness of the doubler plate were brought out.