框支转换梁受力特征研究

Study on mechanical behavior of frame-supported transfer beam

为全面了解框支转换梁的受力特征并提出偏心受拉梁的判定依据,完成了两榀1∶4缩尺的单跨框支剪力墙结构模型的低周交变试验,并以试验结果为基础,对墙肢肢数变化、墙肢洞口宽度变化、框支梁尺寸变化、墙肢偏心变化、墙肢形式变化等情况下框支梁的受力特征进行有限元模拟。研究显示,框支梁相对受拉区高度受跨高比、墙肢位置、洞口大小等因素影响,而下述情况框支梁不易成为偏心受拉梁:一是框支墙在框支柱端部布置且形心落在框支柱范围内时;二是跨中布置的框支墙长度小于2倍梁高,且任何部位到框支柱的距离大于框支梁梁高。

To deeply understand the transfer beam＇s stress characteristics and to propose the criterion of the eccentric-tensional-beam,tests of two one-forth-scale specimens under cyclic load reversals were implemented. Based on the test,finite element simulations on various number of piers,width of opening,dimension of transfer beam,eccentric of pier,and different type of piers were carried out. The results show that the relative height of tensile zone of frame-supported beams is affected by span-depth ratio,position of pier,size of structural opening and other factors. Frame-supported beams are unlikely to become eccentric-tensile-beam under two conditions as follows：（1） frame-supported wall is arranged at the end of frame-supported column and the centroid of the beam is confined the range of frame-supported column; （2） frame-supported wall is located at mid-span,with the length of pier less than twice of the depth of the beam and the distance between any position of frame-supported wall to frame-supported column is greater than the depth of frame-supported beam.