中空夹层CFRP-钢复合管海水海砂混凝土短柱轴压性能试验研究OA

To address the corrosion vulnerability and insufficient stability of double-skin concrete-filled steel tube members in chloride-rich marine environment,a seawater and sea sand concrete-filled double-skin CFRP-steel composite tube(SFDCT)column was proposed.Monotonic axial compression tests were conducted on 36 SFDCT columns and four concrete-filled double-skin steel tube reference specimens.The test parameters included CFRP layers,hollow ratio,and inner tube diameter-to-thickness ratio.The results show that increasing the CFRP layers can significantly improve the bearing capacity of the specimen,and the circumferential confinement of CFRP can effectively delay the buckling of the outer carbon steel tube.Specimens with smaller hollow ratios(0.51,0.67)exhibit up to a 21.9%higher bearing capacity and improved ductility compared to those with larger hollow ratios(0.85).The smaller the inner stainless tube diameter thickness ratio,the stronger the anti-buckling ability of the inner stainless tube.Considering the influence of CFRP on the yielding mechanism of composite columns,a theoretical formula for the minimum inner stainless tube thickness was derived to achieve the ideal failure mode in which the outer tube buckles first and the inner tube fails later,thereby fully exploiting the material capacity.On this basis,a formula for calculating bearing capacity for SFDCT columns was developed.It is more accurate than existing design models and can inform the design and application of such structures.