论文部分内容阅读
屈曲前变形对压弯构件的弯扭屈曲,既有产生附加弯矩的不利影响,又有形成反向拱的有利作用.通过引入参数α=1-N/NEx和β=1/(1-E_(I_y)/E_(I_x))~1/2来反映这2个因素的影响,并给出了考虑这2个参数与规范形式一致的计算公式.以常用型钢截面为研究对象,探讨了β对屈曲前变形压弯构件弯扭屈曲的影响,研究表明:可以不考虑I、HN型钢截面的压弯构件屈曲前变形的影响;适当考虑HM型钢截面的压弯构件屈曲前变形的影响;应该考虑HW型钢截面的压弯构件屈曲前变形的影响.以型钢截面作为研究对象获得的这些结论,适用于具有类似截面特性的焊接组合截面.以工程可以接受的误差5%为限得到:当N/NEx≥0.05时,应该考虑屈曲前变形的影响,否则,会使结构计算偏于不安全;当N/NEx<0.05时,可以忽略不计其影响.
The flexural and torsional buckling of the bending and bending members caused by the pre-buckling deformation not only has the adverse effect of the additional bending moment but also has the beneficial effect of forming the reverse arch. By introducing the parameters α = 1-N / NEx and β = 1 / (1- E_ (I_y) / E_ (I_x)) ~ 1/2 to reflect the influence of these two factors, and gives the calculation formula that takes these two parameters into line with the canonical form.With the common section of steel as the research object, The results show that the influence of pre-buckling deformation on the bending and bending of I-section and H-section can be neglected. The influence of pre-buckling deformation on the bending section of HM section can be considered properly. The effect of pre-buckling deformation on the bending-bending members of the section of the HW section should be taken into account. These conclusions obtained from the section of the section steel are suitable for the welded section with similar cross-section characteristics. The limit of 5% of the acceptable error is: N / NEx ≧ 0.05, the effect of pre-buckling deformation should be taken into account, otherwise, the structural calculation will be unsafe. When N / NEx <0.05, the effect can be neglected.