钢梁突缘支座部分的“压剪”效应

本文用有限元方法对在集中荷载下钢梁突缘支座处的截面腹板及翼缘内平行于截面的剪应力分布进行了研究。分析指出,当荷载作用点接近支点时,梁端截面将承受很大的垂直压应力;是以压缩及剪切变形为主,呈现“压剪”效应。腹板仅承受理论计算剪力的74％左右,翼缘负担23～26％的剪力,远非初等材力理论的腹板负担95％～97％,翼缘负担5％～3％截面剪力的论述,且离荷载作用点约100mm处的截面,上翼缘产生负剪力;上翼缘负担的剪力远大于下翼缘。本文所作的理论分析与文献[3]曾对同一问题进行的试验研究结论是一致的。这对工程上组合梁及吊车梁的设计具有实际意义。文中对文献[3]的试验结果作了综述。

Effect of Compression-Shear at Supporters in Simply Supported Steel Beam with I Sections

The shear stress distribution parallel to the directions of cross sections in both web and flange at the supported end of an I-beam Was evaluated by using the F.E.M in this paper.The analysis showed that, when loading point is in the vicinity of the supports,the end cross sectio -n of the I-beam would be subjected to more compress ivc forces and behav -es compressive and shear deformation mainly which forms the effect of "compression-shear". The web is only subjected to about 74% of the cal -culated full shear force and the flange is subjected to 23-26% .which is different from the 95-97% for web and 3-5% for flange given in Elementary Material Mechanical Theory. At a distance about 100mm from the loading point the upper flange is subjected to negative shear force whioh is much greater than that in the lower flange in value. The theoretical analysis conducted in this paper agrees well With the conclusions in Ref.[3].And it can be used for designing composite I-beam and I-typed crane beam. The experimental results of reference [3] arealso reviewed briefly,in this paper.