中石油大厦斜交网格X型节点试验研究

为了解斜交网格中X型节点的受力性能,进行相似比为1∶5的4个X型节点模型试验,并利用ABAQUS软件开展对应的数值模拟分析,试验的主要参数为试件节点区体积配箍率和加载方式。试验结果与数值模拟一致表明:加载过程中,节点区变形不显著,达到极限荷载时刻,试件突然破坏,显然X型节点的破坏方式属于脆性破坏。其次,等值加载与差值加载两种不同加载方式对节点极限荷载的影响较小,实际结构存在的差值受载方式对节点产生的不利作用可以忽略。提高X型节点区的体积配箍率可减小节点区横向膨胀变形,且在保证节点区最小体积配箍率大于1.44%的前提下,斜柱将先于节点区破坏,节点区将能有效传递斜柱内力,起到良好的联结作用,满足"强节点,弱柱"的要求。

Experimental study on the X-shaped joints in the oblique crossing lattice of the China Petroleum Building

In order to study the mechanical behavior of the X-shaped joints in the oblique crossing lattice,four 1∶5 scale models of the X-shaped joints are tested,and the corresponding numerical simulations are carried out using the ABAQUS software.The main parameters of the experiment are the volumetric percentages of stirrups in the joint core and the loading mode.The results of the test and the numerical simulation consistently show that in the loading process,the deflection of the joint core is insignificant.Once the load reaches the critical level,the models are damaged suddenly.The failure mode of the X-shaped joints is brittle.The equivalent loading mode and difference loading mode have minor influences on the critical load.The negative effect of the subsistent difference loading mode on the prototype structure can be neglected.Increasing the volumetric percentages of stirrups in the joint core can decrease the lateral expansion deflection of the joint core.When the minimum volumetric percentage of stirrups is more than 1.44%,the joint core is able to deliver the internal force effectively before the damage of the oblique column.The joint core is a good connection.The joint can meet the requirement of "strong joint,weak column".