推出试验中摩擦接触效应的数值分析

建立精确有效的2D非线性有限元模型,以研究组合桥梁中预制混凝土板和钢梁间抗剪连接件的力学性质。考虑材料非线性本构关系,采用4节点平面单元,该模型还对大梁翼缘与混凝土板以及混凝土板底部双头螺柱与混凝土之间的摩擦接触面进行了有限元分析。将数值分析结果与试验结果进行比较。每个试件中含有4个或9个双头螺柱。首先,给出能够精确模拟经典3D实际问题的2D数值分析法:等值法。然后,进行数值计算,研究摩擦系数对试件加载滑动性能的影响以及试件的内部变形与内力分布情况。最后,利用参数研究法和实际经验更好地进行连接件设计。

Numerical Analysis of Frictional Contact Effects in Push-Out Tests

This paper proposes an accurate and efficient 2D nonlinear finite element model to investigate the mechanical behaviour of the shear connection between prefabricated concrete slab and steel girder in composite bridges. Beside material nonlinear constitutive laws and 4-noded plane elements, frictional contact finite elements are introduced in the model at the steel-concrete interface between the girder flange and the concrete slab, between the studs and the embedding concrete and at the base of the concrete slab. Numerical results are compared against experimental results of push-out tests. The tested specimens comprise 4 or 9 studs per slab. Firstly, it is shown that 2D numerical analysis may be accurately used for simulating the original truly 3D problem: a "layer-equivalence" methodology is proposed. A numerical investigation is then carried out to study the influence of the friction coefficient on the load–slip behaviour of the specimen and the distribution of internal deformations and forces in the specimen. A parametric study and some practical recommendations could follow this numerical approach for a better design of the connection.