复合加固木柱滞回特性试验研究  

Experimental study on hysteretic performance of composite strengthened timber columns

作　　者：阿斯哈 周长东[2] A Siha;ZHOU Changdong(School of Civil Engineering,Inner Mongolia University of Technology,Hohhot 010051,China;School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]内蒙古工业大学土木工程学院,内蒙古呼和浩特010051 [2]北京交通大学土木建筑工程学院,北京100044

出　　处：《建筑结构学报》2023年第11期181-190,共10页Journal of Building Structures

基　　金：国家自然科学基金项目(52078030,51678039);内蒙古自治区高等学校科学技术研究项目(NJZZ23077)。

摘　　要：为了在现代木结构中研发一种新型复材木构件,并为古建木柱提供可靠加固技术,前期提出了内嵌钢筋外包碳纤维(carbon fiber reinforced polymer,CFRP)布的复合加固方法。为了研究复合加固木柱的滞回特性,以内嵌钢筋数量、外包CFRP布加固量和木柱截面形状为变量,开展了16根加固及未加固木柱的低周往复荷载试验。结果表明:加固木柱均为受拉侧木材纤维的断裂破坏,复合加固方法不能改变木柱的破坏形态,但能延缓破坏的进程;经复合加固,木柱的承载力可提高60%,极限位移提高率可超过85%,内嵌钢筋的布设位置影响其加固效果,随着CFRP布加固量的增加,木柱的承载力提高,耗能得到改善;圆形木柱的骨架曲线基本包络了方形木柱的,可知复合加固方法对圆形木柱的加固效果更优;复合加固木柱的刚度退化系数不断减小,圆形木柱的刚度退化系数普遍大于方形木柱的;等效黏滞阻尼系数呈先减小后增大的趋势,复合加固方形木柱的耗能性能优于圆形木柱;木柱柱身基本不发生变形,损伤和破坏主要位于底部临近固结区域;内嵌钢筋可以与木材协调工作以提高木柱的滞回性能,CFRP布能够约束木材的横向膨胀,延缓木柱破坏的进程,进而提升其抗侧性能。A composite reinforcement method with near surface mounted steel bars and wrapped carbon fiber reinforced polymer(CFRP)strips was proposed to achieve a new composite timber element for modern timber structures,and to provide reliable strengthening technique for historical timber columns.The hysteretic performance of composite strengthened and un-reinforced timber columns was investigated by taking the number of steel bars and CFRP strips and the shape of cross sections as variables,and lateral cyclic loading tests on 16 strengthened and un-reinforced timber columns were carried out.Test results indicate that the strengthened timber columns show tensile rupture of timber grain,the composite reinforcement method cannot change the failure mode,but can delay the failure process.After composite reinforcement,the bearing capacity of timber column can be improved by about 60%,and the increase rate of the ultimate displacement could be more than 85%.The arranged location of the mounted steel bars influences the strengthening effectiveness.With increase in the number of CFRP strips,the ultimate load is enhanced,and the energy dissipation is improved.The skeleton curves of the circular columns basically envelop the curves of square columns,which indicates that the composite reinforcement method has better strengthening effectiveness on circular timber columns.The stiffness degradation coefficients of strengthened timber columns decrease continuously;the coefficients of circular timber columns are generally greater than those of square columns.Moreover,the equivalent viscous damping ratios firstly decrease and then increase,and the energy dissipation capacity of square columns is better than that of circular columns.The column body remains undeformed,damage and failure are mainly concentrated at the bottom of the column near the consolidated section.The mounted steel bars could work together with timber to enhance the hysteretic performance of the timber columns.The CFRP strips are able to restrain the lateral expansion of

关 键 词：木柱 复合加固 内嵌钢筋 外包CFRP布 低周往复荷载 滞回性能 

分 类 号：TU366.2[建筑科学—结构工程] TU317.1