局部穿透腐蚀高强钢管混凝土柱抗冲击性能研究

Anti-impact performance of high-strength concrete-filled steel tubular columns with local penetrating corrosion

钢管混凝土(concrete-filled square steel, CFST)出现局部腐蚀时,其抗冲击性能会受到明显影响。为此,利用ABAQUS软件建立了方形高强钢管混凝土柱(high-strength concrete-filled square steel, HSCFST)数值模型,考虑开缝角度、开缝长度、冲击面和冲击能等参数对HSCFST柱抗冲击性能的影响。结果表明:局部穿透腐蚀影响下,水平开缝的正面冲击构件的裂缝会出现闭合现象,而侧面冲击构件破坏时裂缝呈现“三角形”形态;冲击力平台值主要受冲击面的影响,其次是开缝角度,而开缝长度主要对承受背面冲击的构件影响较大;开缝角度的增大和开缝长度的减小与冲击力平台值的提高成正比,承受正面冲击的构件其抗冲击性能优于承受侧面和背面冲击的构件。减小开缝角度会增大构件的跨中挠度,受正面冲击的构件的跨中挠度要小于受背面和侧面冲击的构件;构件的能量吸收率与开缝长度的增加成正比,与开缝角度的增大成反比,受背面冲击的构件的能量吸收率最高,正面冲击则最小。基于大量参数分析结果,提出了局部穿透腐蚀作用下HSCFST柱的动力抗弯承载力影响系数的实用计算方法。

Anti-impact performance of concrete-filled square steel(CFST)can be obviously affected when local corrosion occurs. Here, the software ABAQUS was used to establish a numerical model of square high-strength concrete filled steel tubular(HSCFST) columns, and effects of parameters of slit angle, slit length, impact surface and impact energy on anti-impact performance of HSCFST columns were considered. The numerical simulation results showed that under effects of local penetrating corrosion, crack of component with horizontal slit under front impact has close phenomenon, while crack of component with horizontal slit under side impact can reveal a “triangle” shape during being damaged;impact force platform value is mainly affected by impact surface, followed by slit angle, and slit length mainly affects components bearing back impact;increase in slit angle and decrease in slit length are proportional to increase in impact force platform value, anti-impact performance of components subjected to front impact is better than that of components subjected to side and back impacts;decrease in slit angle can increase midspan deflection of components, and midspan deflection of components subjected to front impact is smaller than that of components subjected to back and side impacts;energy absorption rate of component is proportional to increase in slit length and inversely proportional to increase in slit angle;energy absorption rate of component subjected to back impact is the highest, while that of component subjected to front impact is the lowest;based on a large number of parametric analysis results, a practical calculation method for the influence coefficient of dynamic bending capacity of HSCFST columns under local penetrating corrosion is proposed.