Q690高强钢加劲T-stub试验及有限元分析

Test and finite element analysis of Q690 high strength steel T-stub joints with stiffeners

首先对两组焊接加劲T-stub节点进行了静力拉伸试验,对比分析了Q690高强钢与Q345普通钢T-stub节点的力学性能。然后采用ABAQUS程序对节点进行了有限元分析,获取了节点荷载-位移曲线、初始刚度、塑性承载力;与试验结果进行对比,验证了有限元模型的有效性;研究了不同设置方式和长宽比的加劲肋对节点刚度、强度、变形能力的影响。研究表明,Q690高强钢T-stub节点的塑性承载力比Q345钢至少提高28%左右,而延性及变形能力较差。采用单边设置加劲肋的方式对节点承载力的影响较小;双边设置加劲肋可以显著提高节点的刚度和承载能力,分别提高1.35和1.43倍左右,但极限后承载力和刚度退化明显加快。当加劲肋长宽比en/et<1.0时,对节点的力学性能影响较大;当长宽比en/et≥1.0时,对节点力学性能的影响甚微。

In order to analyze differences and similarities of mechanical properties between Q690 high strength steel and Q345 normal steel, tensile test on two groups of welded T-stub connections is conducted firstly. Secondly, based on the tensile test results, the joints are analyzed by the ABAQUS finite element software. The load-deformation curves, initial stiffness and plastic strength of the joints are obtained and also compared with the test results to verify the validity of the finite element model. Impacts of arrangement and length-width ratio of the stiffener on stiffness, strength and deformation of joints are studied. Results show that plastic bearing capacity of Q690 steel T-stub joints is at least 28% higher than that of Q345 steel, but the ductility and deformation capacity is poor. Influence of one side stiffener on stiffness and plastic strength of the joints is little. Double sides stiffener can improve significantly the stiffness and bearing capacity of the joints, which are increased by about 1.35 and about 1.43 times, but the degradation of bearing capacity and post-limit stiffness is obviously accelerated. When the length-width ratio en/et of the stiffener is less than 1.0, it has a large influence on the mechanical properties of the joints. Otherwise, its influence may be ignored.