外包钢板-混凝土组合连梁非线性有限元分析:传力与变形机理研究

Nonlinear finite element analysis of concrete filled steel plate composite coupling beams: force and deformation mechanics

在外包钢板-混凝土组合连梁试验研究的基础上,对组合连梁试件和不同参数取值的补充模型进行了非线性有限元分析。有限元分析得到的滞回曲线与试验曲线吻合良好,能较好地模拟组合连梁的受力行为。通过应力分析,发现内填混凝土的工作机制类似于斜压杆,其压力沿着连梁对角线方向从一端的受压侧传递到另一端的受压侧。外包钢板承担的剪力比例和弯矩比例的范围分别为0.36~0.76和0.57~0.82;混凝土的剪力与轴压力之比和连梁的高跨比近似相等。连梁的侧向位移由节点区变形引起的梁端转角、连梁的弯曲变形与剪切变形产生;在常用的跨高比范围内,剪切变形产生的侧向位移在总位移中占有较大比例,且受跨高比的影响很大。

Based on the experimental study,nonlinear finite element analysis was carried out for the concrete filled steel plate composite coupling beams. The hysteretic loops obtained from the finite element analysis were in good agreement with the test results,which indicated that the finite element model could well simulate the behavior of composite coupling beams. The concrete infill was found to work as a diagonal compression strut in the coupling beam,in which the compression force was transmitted from the compression side at one beam end to that at the other. The proportions of shear forces and bending moments sustained by the steel plates were between 0. 36 and 0. 76,and between 0. 57 and 0. 82,respectively. The shear-to-compression ratios of the concrete infill were approximately equal to the corresponding height-to-span ratios of the coupling beams. The lateral displacement of the coupling beam was caused by the beam end rotations due to connection region deformations,flexural and shears deformations of the coupling beam. The shear deformation was a great contributor to the total displacement for the coupling beams with commonly used span-to-height ratios.