大直径焊钉连接件抗剪性能试验

Experimental Study on Shear Behavior of Large Stud Connectors

摘要:

为了解决部分情况下组合结构桥梁钢混结合面焊钉布置过密的问题，通过直径22 mm,25 mm和30 mm焊钉的抗剪承载性能模型试验比较分析了直径25 mm和30 mm大直径焊钉相对于直径22mm常规焊钉破坏模态、承载力、刚度和变形性能的差异,并对国内外桥梁规范中焊钉抗剪承载力设计式对于大直径焊钉的适用性进行了评估.研究结果表明,相对于直径22 mm焊钉，直径25 mm和30 mm焊钉的抗剪承载力平均增大约14%和42%,抗剪刚度平均增大约35%和106%.《公路钢结构桥梁设计规范(送审稿）》、规范Eurocode 4和规范AASHTO LRFD中的抗剪承载力设计式均可较为保守地计算大直径焊钉的抗剪承载力，其中Eurocode 4最为保守.试验值与设计值的比值随焊钉直径的增加而减小.

Abstract:

Stud connectors are over densely arranged in steel concrete composite bridges in some cases. To address this issue, shear behavior of stud connectors with the diameters of 22mm, 25mm and 30mm were experimentally studied. Based on the test results, the failure model, shear strength, shear stiffness and slip capacity of large diameter studs (25mm and 30mm studs) were compared with those of normal diameter studs (22mm studs). In addition, the applicability of the design equations specified in existing codes to large diameter studs were evaluated. The results show that compared with 22mm studs, the average shear strength of 25mm and 30mm studs increase by about 14% and 42%, respectively, and the shear stiffness increase by about 35% and 106%, respectively. The design equations specified in Chinese Code (draw), Eurocode 4 and AASHTO LRFD give conservative predictions for the large diameter studs, and Eurocode 4 gives the most conservative values. The ratio of the measured value to the calculated value decreases as the stud diameter increases.