加强板作用下方钢管柱H型钢梁节点抗震性能研究

RESEARCH ON THE SEISMIC BEHAVIOR OF H-BEAM JOINTS OF SQUARE STEEL TUBULAR COLUMNS WITH STIFFENING PLATE

梁柱焊接节点在地震作用下易发生脆性破坏。为探究节点处增设加强板对其抗震性能的影响,基于方钢管柱与H型钢梁焊接节点,通过数值模拟不同节点模型在梁端往复荷载作用下的受力性能,得到不同加强板厚度、强度、方钢管宽厚比下的滞回曲线、骨架曲线及其变形规律。结果表明:节点处增设加强板时,节点的承载力提高了124%,塑性铰外移;对节点受力性能影响较大的是加强板厚度,节点破坏时塑性铰位置随加强板厚度增大逐渐背离加强板向外,当加强板厚度为8 mm时,节点更容易发生破坏,破坏形式为加强板出现扭曲破坏;加强板强度越大,加强板应力集中区域面积越小,抵抗变形能力越强;节点承载能力随着方钢管宽厚比的增大而逐渐减小,其中宽厚比每增加1 mm,承载力降低4024 N。表明该节点形式受力性能较好,满足抗震设计规范中的“强节点、弱构件”要求。

The welded joints of beams and columns are liable to occur brittle failure under earthquake.Based on the welded joints of square steel tubular columns and H-shaped steel beams,in order to explore the effects of adding reinforcement plates at the joints on their seismic performance,the hysteretic curves,skeleton curves and deformation law under different thicknesses,strengths,width-thickness ratios of square steel tubular plates were obtained by the numerical simulation of the mechanical properties of different joint models under reciprocating load at the end of the beam.The results showed that the bearing capacity of the joints increased by 124%and the plastic hinge moved outward.The thickness of the stiffening plate had a great influence on the mechanical properties of the joints.The plastic hinge position gradually deviated from the stiffening plate outward with the increase of the stiffening plate when the joints were damaged.When the thickness of stiffening plate was 8 mm,the joint was more likely to be damaged,and the failure mode was distorted failure of the stiffening plate;the larger the strength of the stiffening plate,the smaller the area of the stress concentration area of the stiffened plate,the stronger the resistance to deformation;the bearing capacity of the joint decreased gradually with the increase of the width-thickness ratio of square steel tube,for every 1 mm increase in the width-thickness ratio,the bearing capacity of the joint was reduced by 4024 N.The analysis showed that the joint had good mechanical properties and could meet the requirements of“strong joint and weak member”in the seismic design code.