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带加劲肋钢-混凝土组合蜂窝梁腹板成排开孔后,主要削弱了其抗剪稳定性和抗剪强度。为探明这一新型桥梁结构的力学特点,采用有限元方法对钢-混凝土组合蜂窝梁开孔腹板的抗剪性能进行了深入研究。对不同边界条件下的开孔腹板进行弹性剪切屈曲分析,考虑孔洞的影响引入径高比和宽高比参数,对实腹板剪切屈曲系数加以修正,并引入约束系数表征约束程度,推导得到了开孔腹板剪切屈曲系数的计算公式。建立开孔腹板抗剪极限承载能力有限元计算模型,考虑材料、几何双重非线性,对不同参数开孔腹板的抗剪承载能力进行了大量的有限元分析,在数据分析基础上量化弹性屈曲荷载和屈曲后荷载对开孔腹板抗剪承载能力的贡献。引入腹板的开孔率参数,提出了开孔腹板抗剪极限承载力的计算公式,同时分析了不同初始几何缺陷对开孔腹板抗剪性能的影响。结果表明:不同边界条件下的开孔腹板剪切屈曲系数公式与有限元值吻合良好;开孔腹板仍可发展一部分屈曲后强度,屈曲后强度可偏保守地表示为开孔腹板塑性强度的30%,开孔腹板抗剪极限承载力计算公式与有限元计算结果吻合较好,且总体偏于安全;不同的初始几何缺陷对开孔腹板荷载-位移曲线形式有较大影响,但对其抗剪承载能力影响很小。
After the webs with stiffened steel-concrete composite honeycomb girder are arranged in rows, the shearing stability and the shear strength are mainly weakened. In order to prove the mechanical characteristics of this new type of bridge structure, the shear resistance of the perforated web of steel-concrete composite honeycomb beam was studied by finite element method. The elastic shear buckling analysis of perforated webs under different boundary conditions is carried out. Considering the influence of holes, the parameters of aspect ratio and aspect ratio are introduced to correct the shear buckling coefficients of the actual webs, and the constraint coefficients are introduced to represent the restraint degree. The formula of shear buckling coefficient of open webs is derived. A finite element model of shear ultimate load carrying capacity of perforated webs is established. Considering the material and geometrical double nonlinearities, a lot of finite element analysis is carried out on the shear capacity of perforated webs with different parameters. Based on the data analysis, Contributions of Buckling and Post Buckling on Shear Carrying Capacity of Perforated Webs. By introducing the parameters of the open area of the web, the formulas for calculating the ultimate bearing capacity of the open web are presented. The influences of different initial geometric imperfections on the shear properties of the open webs are also analyzed. The results show that the formulas of shear buckling coefficient of open web under different boundary conditions are in good agreement with the finite element values. The open web can still develop some post-buckling strength. The buckling strength can be conservatively expressed as the plasticity of open web The ultimate shear bearing capacity of the perforated web is in good agreement with the finite element method and is generally safe. The different initial geometrical imperfections have a great influence on the load-displacement curve of the perforated web , But its shear bearing capacity has little effect.