CFRP加固古建筑榫卯节点振动台试验

Shaking table test on Chinese ancient tenon-mortise joints strengthened by CFRP

为保护古建筑,采用振动台试验方法,研究碳纤维增强塑料(CFRP)加固古建筑榫卯节点的抗震性能。基于某古建筑的实际尺寸,制作了1∶8缩尺比例的古建筑木结构空间框架模型,并考虑榫卯连接为燕尾榫形式,进行了振动台试验。通过白噪声激励,获得了构架的基频及阻尼比;通过输入不同峰值的El-Centro波,获得了构架的动力放大系数、典型节点的位移及加速度响应特征。结果表明:CFRP加固榫卯节点后,构架基频增大,阻尼比减小;在地震波作用下,加固后的构架具有更小的位移及加速度响应,且随着地震波峰值增大,减震效果越明显;此外,在地震波作用较强时,加固构架的动力放大系数明显小于未加固构架的;因此,CFRP加固古建筑榫卯节点具有较好的减震效果。

In order to protect Chinese ancient buildings,CFRP（Carbon Fiber Reinforced Plastic） was used to strengthen the tenon-mortise joints of the buildings and their strengthening effects were studied by the shaking table test.Employing Yanwei tenon-mortise as the connections,a wooden frame model with a scale of 1∶8 to an ancient wooden building was built.CFRP was used to strengthen the tenon-mortise joints of the model to enhance its stability.Under white noise excitation,the fundamental frequencies of the model in both strengthened and unstrengthened conditions were obtained.By inputting El-Centro earthquake waves of different peak accelerations,the dynamic magnification factor of the model were obtained,and the responses of displacement and acceleration for the typical nodes of the model were discussed.Results show that after its tenon-mortise joints are strengthened by CFRP,the fundamental frequency of the model increases while its damping ratio decreases.Under earthquake,the strengthened model responds with smaller peak displacement and acceleration.With the increase of earthquake intensity,CFRP tends to perform better.Besides,under strong earthquake,the dynamic magnification factor of the strengthened model decreases significantly.Therefore,CFRP is effective for seismic strengthening of the tenon-mortise joints of Chinese ancient wooden buildings.