焊接工字钢梁腹板极限承载力的理论计算和试验

为了解焊接工字钢梁的承载力极限状态，采用有限元法对焊接工字钢梁腹板在剪力、弯矩、局部压力单独作用和联合作用下的极限承载力进行了计算，并进行了19根试件的试验研究．结果表明：高厚比较大的腹板具有很高的屈曲后强度，腹板的高厚比和横向加劲肋的间距是影响腹板抗剪极限承载力的主要因素；在腹板高厚比满足一定限值时，受弯腹板的屈曲对梁的抗弯极限承载力几乎没有影响；弯剪共同作用的腹板，当弯矩小于翼缘所能承受的弯矩时，弯矩对抗剪极限承载力的影响不大，破坏形式仍为腹板的剪切屈曲破坏．建议实际工程中利用腹板屈曲后强度时腹板高厚比限值为250，横向加劲肋的间距为(0．8～1．5)h0．

Theoretical Analysis and Experiment on the Ultimate Load Capacity of Web Plates of Welded Ⅰ-Section Girders

In order to thoroughly understand the ultimate state of load capacity of the welded I-section girder,the finite element analysis and experimental research for the ultimate load capacity of the web plates of welded I-section girders are carried out,which subjected to the actions of shearing forces, bending moments and local pressure individually or their combination. The results show that the ratio of width-thickness (h_0/t_w) of web and the distance between the transverse stiffeners are the main factors to affect the post buckling strength and the ultimate load capacity when the web plate subjected to shear forces. When the limitation imposed on the web ratio (h_0/t_w) has been satisfied, the influence on the ultimate load capacity by the buckling of the web plate subjected to bending moments can be neglected. When the bending moments are lower than the bending capacity of the flange plates, it will affect lightly the ultimate shearing capacity of the web plates which co-llapsed in the shear mode. The values of the ratio (h_0/t_w) and the distance between the transverse stiffeners utilizing the post-buckling strength are suggested to be 250,(0.8-1.5) h_0 respectively for application in actual engineering.