1.Xi’an University of Architecture &2.Technology
The National Science Fund for Distinguished Young Scholars;The National Natural Science Foundation of China (General Program, Key Program, Major Research Plan)
Four groups of concrete-filled steel tube specimens with different internal structure forms such as setting stiffening ribs and reinforcing lattice angles were tested. The test results show that the inserted reinforcing lattice angle can delay concrete cracking in tensile zone and steel tube yielding in compression zone, and improve its bending behavior effectively. ABAQUS is used to simulate the test specimen, and the finite element results are in good agreement with the test results. On this basis, the influence of the steel tube diameter to thickness ratio, steel-reinforced limb spacing, steel-reinforced size, steel-reinforced strength, concrete strength on the bending behavior of the members were analyzed. The results show that the main parameters that affect the bending behavior of members are the steel tube diameter to thickness ratio, steel-reinforced size, steel-reinforced strength, concrete strength and steel-reinforced limb spacing have little influence on its bending bearing capacity. The bending bearing capacity and flexural rigidity of specimens are calculated by using Chinese, US and Europe codes, and the calculated results are compared with the test results. The results show that the calculation of bending bearing capacity is conservative, and the calculation of flexural rigidity is conservative by using US and Europe codes.