Some essential causes of composite frame column showing pre going strain in pulling steel under laterally reversed low cyclic loading after entering elastic plastic phase are analysised.

• 提出了水平低周反复荷载下叠合框架节点刚度弱化现象及加强节点刚度的构造措施,对高效预应力叠合框架在地震区的应用具有现实意义。