偏压作用下碳纤维布加固H型钢柱承载力分析

Analysis on Bearing Capacity of H-shape Steel Columns Strengthened by Carbon Fiber Reinforced Polymer under Eccentric Compression

随着时代的飞速发展,世界上采用钢结构体系的建筑数量急剧增加。考虑到许多采用H型钢柱的钢结构建筑其柱构件可能会发生老化或者建筑本身改变使用功能后钢柱承载力可能不足,故对碳纤维布(carbon fiber reinforced polymer,CFRP)加固偏压H型钢柱进行了理论推导和试验研究工作,通过参考已有规范和采用等代的思想将碳纤维增强复合材料面积转化为相应的钢材面积,得出偏压H型钢柱经碳纤维增强复合材料加固后极限承载力计算公式,并将理论推导的计算结果和实际试验的观测结果进行对比,计算值和试验值的误差稳定在一定范围内,证明了公式计算的准确度。讨论了碳纤维增强复合材料不同加固层数和不同偏心距对H型钢柱加固后极限承载力的影响,研究表明碳纤维增强复合材料加固偏压H型钢柱会提高钢柱的承载能力,但随碳纤维增强复合材料层数的增加,承载能力提升的幅度会逐渐变小;碳纤维增强复合材料对偏心距较大试件的加固效果明显强于偏心距较小试件的加固效果。通过理论推导与试验表明碳纤维布加固法是在几乎不影响原钢构件受力性能情况下加固钢构件的较好方法之一。

With the rapid development in the era,the number of buildings using steel structure systems increases rapidly.To consider that H-shaped steel columns of steel structure were adapted in many buildings,the column members of the buildings may be ageing,or the bearing capacity of steel column in the building itself may be insufficient after function changed.Therefore,the theoretical derivation on the biased compression H-shaped steel column strengthened with carbon fiber reinforced polymer(CFRP)and experimental research work was conducted.The carbon-fiber-reinforced polymers area was converted into the corresponding steel area through the reference to the existing standards and adopting the idea of equivalent generation.The ultimate bearing capacity calculation formula of the biased H-shaped steel column strengthened with carbon-fiber-reinforced polymers was derived.And the calculation result of theoretical derivation was compared with the observation results of actual experiment.The biases between the calculated value and the experimental value are stable within a specific range,which proved the accuracy of the formula calculation.The influence of CFRP strengthened layers on different carbon-fiber-reinforced polymers and different eccentricities on ultimate bearing capacity of strengthened H-shaped steel columns was discussed.The results show that:biased compression H-shaped steel columns strengthened with carbon-fiber-reinforced polymers under eccentric compression can increase the bearing capacity of the steel columns.However,as the number of layers of carbon fiber-reinforced polymers increases,the bearing capacity amplitude will gradually decrease.The strengthen effect of carbon-fiber-reinforced polymers on specimens with larger eccentricity is stronger than that of specimens with smaller eccentricity.Through the theoretical derivation and experiments,it shows that the carbon fiber cloth strengthen method is one of the better methods to strengthen the steel members under conditions that hardly affect the mechanical performance of original steel members.