偏心支撑半刚接钢框架的动力特性及抗震性能试验研究

Experimental study on dynamic characteristics and seismic performance of semi-rigid steel frame with eccentric brace

偏心支撑半刚接钢框架是一种新型抗震结构体系,为研究其动力特性及抗震性能,进行了4个三层空间框架试件的试验研究。动力特性测试表明,随着梁柱节点转动刚度的降低,结构自振频率减小,阻尼比增加。循环加载试验表明,节点刚度和承载力对偏心支撑框架结构的滞回性能有显著影响,节点刚度和承载力越高,滞回性能越好,节点刚度较低的偏心支撑框架不宜用于抗震设防区;偏心支撑显著增加了半刚接钢框架的抗侧刚度,使得节点刚度对框架刚度的影响减弱,但降低了结构延性;结构的塑性变形主要来自节点域、消能梁段及梁柱节点连接件;多层偏心支撑框架的侧移变形为剪切型,层间屈服位移角较大。

Semi-rigid steel frame with eccentric brace is a new type of seismic structural system.In order to study its dynamic characteristics and seismic performance,four three-story space frame specimens were tested.Dynamic test results show that,with the reduction of rotational stiffness of beam-column connections,the natural frequency of frames decreases,and the vibration period and damping ratio increase.Cyclic loading test results show that the stiffness and strength of beam-column connections have a significant effect on the hysteretic behavior of the eccentrically braced frame.The higher the connection stiffness and strength are,the better the hysteretic behavior is.Eccentrically braced frame with lower connection stiffness should not be used in seismic zones.Eccentric brace can increase the lateral stiffness of the semi-rigid steel frame significantly,and reduce the effect of the connection stiffness on the frame stiffness.But eccentric brace can also reduce the frame ductility.The plastic deformation of structures is mainly from panel zones,links and beam-column connecters.The lateral deformation of multi-story eccentrically braced frame is shear type and the yield drift angle is relatively large.