形状记忆合金丝加固古建筑木结构直榫节点抗震性能研究  

RESEARCH ON ASEISMIC BEHAVIOR OF STRAIGHT TENON JOINTS REINFORCED BY SMA STRINGS IN ANCIENT TIMBER BUILDINGS

作　　者：张锡成[1,2] 胡成明 吴晨伟 韩乙楠 张玉涛 ZHANG Xi-cheng;HU Cheng-ming;WU Chen-wei;HAN Yi-nan;ZHANG Yu-tao(School of Civil Engineering,Xi’an University of Architecture&Technology,Xi’an,Shaanxi 710055,China;Key Lab of Structural Engineering and Earthquake Resistance,Ministry of Education(XAUAT),Xi’an,Shaanxi 710055,China)

机构地区：[1]西安建筑科技大学土木工程学院,陕西西安710055 [2]西安建筑科技大学结构工程与抗震教育部重点实验室,陕西西安710055

出　　处：《工程力学》2022年第4期164-176,共13页Engineering Mechanics

基　　金：国家自然科学基金项目(51508454);陕西省自然科学基础研究基金项目(2019JM-078)。

摘　　要：古建筑木结构中的半刚性榫卯节点在地震中往往先于梁柱等构件发生破坏,是加固保护的关键部位。设计了一种新型形状记忆合金(SMA)丝预防性加固装置,对采用该装置的5个直榫节点及1个未加固节点进行了低周反复荷载试验,研究了采用不同根数和不同预拉应变的SMA丝加固节点的破坏形态、弯矩-转角关系、强度退化、刚度退化、耗能性能、自复位能力以及变形能力,并提出了SMA丝加固直榫节点的抗弯承载力计算方法。结果表明:SMA丝加固节点的抗弯承载力均有不同程度的提升,加固节点的最大抗弯承载力为未加固节点的1.49倍;与未加固节点相比,加固节点的强度退化不严重,表明SMA丝可以在节点转角较大时,仍能持续为节点提供抗弯承载力;加固节点最大转动刚度是未加固节点的2.24倍;随着节点转角的增大,未加固节点的耗能能力逐渐减小,而加固节点的耗能能力先增大后减小;在相同的转角下,随着SMA丝根数和预拉应变的增加,节点相对残余变形均减小,自复位能力增强。研究成果可为古建筑木结构榫卯节点的预防性加固保护提供参考。The semi-rigid mortise-tenon joints in the wooden structures of ancient buildings are often destroyed before beams and columns under major earthquakes, which are the important positions for reinforcement and protection. A new type of shape memory alloy(SMA) preventive reinforcement device is designed, and lowcyclic loading tests are carried out on five reinforced joints and one unreinforced joint. The failure modes,moment-rotation relationship, strength degradation, stiffness degradation, energy dissipation, self –centering ability and deformation capacity of the joints reinforced by SMA strings with different numbers and different pretension strains are studied. A calculation method for bending capacity of straight tenon joints reinforced by SMA strings is established. The results show that the bending capacity of the joints after SMA reinforcement is improved. The maximum bending capacity of the reinforced joint is 1.49 times that of the unreinforced joint.Compared with the unreinforced joint, the strength degradation of the reinforced joints is not serious, which indicates that the SMA strings can still continue to provide the bending capacity for the joints when the rotation is large.The maximum rotational stiffness of the reinforced joint is 2.24 times that of the unreinforced joint.With the increase of the rotation of joints,the energy dissipation of unreinforced joint gradually decreases,however the energy dissipation of reinforced joints increases first and then decreases.At the same rotation,the relative residual deformation decreases with the increase of numbers and of pretension strains of SMA strings,and the selfcentering ability is enhanced.The results of research can provide a reference for the preventive conservation of the mortise-tenon joints in ancient timber structures.

关 键 词：古建筑木结构 直榫节点 形状记忆合金丝 滞回性能 抗弯承载力 

分 类 号：TU366.2[建筑科学—结构工程]