圆中空夹层不锈钢管水泥砂浆短柱轴压性能研究

Axial Compressive Behavior of Circular Mortar-Filled Double-Skin Stainless Steel Tubular Stub Columns

海洋工程平台塔架结构中,圆形截面中空双钢管是主要受力构件,工程界十分关注其受压性能和耐腐蚀性能。为研究圆中空夹层不锈钢管水泥砂浆短柱的轴压力学性能,以外不锈钢管壁厚、内碳素钢管直径和是否含夹层水泥砂浆为试验变量,共设计了12个短柱试件。分析各试件的破坏情况、荷载-位移曲线、承载力、变形能力及应变特征,研究不同变量对极限承载力的影响规律。结果表明:试件破坏形态为外钢管端部或中部局部屈曲破坏;随着不锈钢管壁厚的增大,试件的轴压承载力近似呈线性增长;夹层水泥砂浆对试件力学性能影响较大,可有效提高试件承载力,抑制外不锈钢管的变形,提高试件延性;对于含夹层水泥砂浆的试件,承载力随空心率增大而减小,不含夹层水泥砂浆的试件,承载力随空心率增大而增大。根据国内外规范以及相关学者提出的理论公式,计算了试件的极限承载力,并与试验承载力进行了对比分析,给出了设计建议。

In the offshore engineering platform tower structures,circular double steel tubes are the main load-bearing members,and the compressive and corrosion resistance behavior is a great concern to design engineers.In order to study the axial compressive behavior of mortar-filled double-skin stainless steel tubular stub column,a set of twelve column specimens was designed using the outer stainless steel tube wall thickness,the inner carbon steel tube diameter and the mortar between two steel tubes as test variables.The failure modes,load-displacement curves,bearing capacity,deformation performance and strain characteristics were analyzed,and the influences of different parameters on the ultimate bearing capacity were studied.The results show that the failure modes of the specimens are the local buckling failure at the end or middle of the outer steel tube.With the increase of the wall thickness of stainless steel tube,the bearing capacity increases linearly.Infilled mortar can effectively improve the bearing capacity,reduce the deformation of the outer steel tube,and improve the ductility of the specimens.For the specimens with infilled mortar,the bearing capacity decreases with the increase of hollow ratio,while for the specimens without mortar,the bearing capacity increases with the increase of hollow ratio.According to different design codes and theoretical formulas proposed by other scholars,the calculated ultimate bearing capacity and test results were compared and analyzed,and the design suggestion was proposed.