负载下盖板加固梁柱刚接节点的简化力学模型

国外已有的试验研究表明:没有初始荷载的情况下采用盖板加固的梁柱刚接节点受力性能良好,其破坏模式都是在盖板末端的梁截面上出现塑性铰;但对于负载下加固节点的受力性能研究则较少。该文在有限元研究的基础上,对盖板和原节点之间的相互作用关系做出合理的假设,并提出了模拟盖板加固的简化力学模型,进一步研究了负载下加固节点的受力性能。通过简化力学模型分析,得到了负载下加固节点中初始荷载与新增荷载在加固盖板与原节点之间的分配关系,负载下盖板加固节点不能视为一个整体来设计,平截面假定也不再满足。同时简化力学模型计算结果表明盖板长度对最终荷载在盖板和原节点之间的分配关系影响很小,盖板厚度是节点负载下加固的主要几何设计参数。

ANALYTICAL MODEL OF COVER-PLATE RETROFITTED STEEL MOMENT CONNECTION WITH INITIAL LOADING

Experimental results abroad indicated that the cover-plate rehabilitated steel moment connection exhibits good loading capacity,with the failure mode of the plastic hinge formed on the beam beyond the reinforced region.However,few studies have been carried out on the rehabilitation of the connection with initial loading.Based on the stress distribution obtained by the finite element analysis,some assumptions are made and a mechanical model is proposed.The mechanical behaviors of the rehabilitated connection with initial loading have been investigated.By the simplified model,the distribution pattern of the initial loads and the additional loads between the cover plates and the original connection is obtained.The design of the rehabilitated connection with initial loading as integrated joint is no longer applicable;neither is the traditional beam theory.The length of the cover plate imposes less influence on the moment distribution between the cover plates and the original connection,but the thickness of the cover plate is the main design parameter.