梁柱-支撑式胶合木框架的抗震性能试验研究

Experimental study on seismic performance of glued laminated timber K-braces frame structures

为实现刚柔并济的高层胶合木结构,分别构造刚度单元和阻尼单元。刚度单元为碳纤维加固的带人字形木支撑的木框架单元,阻尼单元为刚度单元基础上增设金属阻尼器的木支撑框架单元。文章分别对一榀单层单跨刚度单元和阻尼单元进行低周往复荷载试验,阻尼单元中金属阻尼器失效后,通过焊接钢板的方式对震损阻尼单元试件进行修复,并进行与前期相同的低周往复加载试验,分析了木框架试件的破坏形态、滞回曲线、骨架曲线、延性、强度退化、刚度退化、耗能能力等抗震性能。研究表明:碳纤维加固的木支撑不会出现失稳和劈裂破坏;增设金属阻尼器的阻尼单元滞回环更加饱满,延性系数较刚度单元提高2.68%~19.2%,显著改善了刚度单元存在的木材构件破坏现象,有效保护了木支撑与梁柱框架;阻尼器失效后,修复后的阻尼单元试件仍持有与刚度单元相当的刚度与承载力,说明阻尼器作为第一道防线破坏后,木框架仍具有一定的抗震性能,形成了以阻尼器为第一道防线,支撑-框架作为第二道防线的二道抗震防线体系。

To achieve a combination of rigidity and ductility in a glulam high-rise structure,a stiffness unit and a damping unit are constructed,respectively.The stiffness unit is a glulam frame with glulam brace reinforced by carbon fiber,and the damping unit is a glulam frame unit with a metal damper added to the stiffness unit.In this work,reversed cyclic loading tests were carried out on a single-floor single-span stiffness unit and damping unit.After the failure of the metal damper in the damping unit,the tested damping unit was renovated by welding steel plates,and the same reversed cyclic loading tests were implemented.Seismic performance,failure patterns,hysteretic curve,skeleton curve,ductility,strength degradation,stiffness degradation,and energy dissipation capacity of the glulam frame specimen were investigated.Results show that instability and splitting failure can be avoided in the carbon fiber-reinforced glulam braces,the damping unit exhibits more stable hysteretic characteristics,and the ductility coefficient is 2.68%~19.2%higher than that of the stiffness unit.Thus,in damping unit,destruction of components can be significantly improved,and glulam braces and beam-column frame are protected effectively.After the failure of the damper,the renovated damper unit specimen still possesses the stiffness and bearing capacity equivalent to those of the stiffness unit,indicating that after the failure of the damper taken as the first line of defense,the glulam frame still has a certain seismic performance,forming a dual seismic defense line system with the damper as the first defense and the braced-frame as the second line of defense.