钢-玻璃组合梁平面内受力性能及计算方法研究

In-plane loading mechanical property and analytical method of steel-glass composite beams

目前国内外对钢-玻璃组合梁结构的受力模式及承载力研究不足,对5个钢-玻璃组合梁试件进行了平面内受力性能试验,并基于多线性和线性材料本构模型进行了有限元分析。研究了采用钢化夹层(胶)玻璃腹板和单片钢化玻璃腹板组合梁的剪压破坏模式及纯弯曲破坏模式,两种破坏模式的区别在于纯弯曲破坏始于梁底弯矩最大部位,而剪压破坏在局部受压及剪跨区域发生。采用我国JGJ 102—2003中关于平面内玻璃肋受弯计算公式分析了组合梁承载力,基于塑性铰线方法提出了该类组合梁承载力的理论计算公式。研究结果表明:剪压破坏时钢化夹层(胶)玻璃腹板随着荷载增大而呈现明显的界面孔隙,相比同厚度的单片钢化玻璃腹板,夹层(胶)玻璃腹板能提高组合梁的弯曲变形能力。增加腹板玻璃厚度和胶结强度均可提高组合梁的承载力,且前者的贡献更为明显,对于后者,剪压破坏和纯弯曲破坏分别取决于结构胶的压缩模量和剪切模量。考虑了胶结部分受拉刚度贡献的有效截面系数能更好预测组合梁的纯弯曲破坏承载力,而提出基于塑性铰线机制的计算方法能更好预测组合梁的剪压破坏承载力。

To address the inadequacy of existing studies on the loading behaviour and resistance of steel-glass composite beams,five beam specimens of this type were investigated through in-plane loading tests and finite element modelling based on multi-linear and linear material constitutive models.The shear compression failure mode of test beams with laminated and single layered thermally toughened glass panels was investigated through a comparison against the pure bending failure mode.It is shown that the difference lies in the fact that the pure bending failure mode is initiated from the bottom surface of the beam subjected to the maximum moment while the shear compression failure mode is initiated from the local compression areas and occurrs within the shear span.Moreover,the suitability of using codified bending formula of glass fins in the analysis of composite beams was studied.A formula based on the plastic hinge method was proposed for the calculation of strength of the composite beams.The research findings show that:interfacial voids in the laminated glass web increase with the load for steel-glass composite beams under shear compression.Compared to single layered thermally toughened glass panel webs,laminated ones can increase the bending capacity of the composite beams.The load carrying capacity of steel-glass composite beams increases with the thickness of glass web and adhesive strength;the effect of the former is more obvious while the effect of the latter is dependent on the compressive modulus for shear compression and shear modulus for pure bending.The strength of composite beams in pure bending can be better predicted using the modified effective sectional coefficient considering the contribution of tensile stiffness while the strength of the composite beams in shear compression can be predicted using the proposed plastic hinge method.