基于三折线半刚性节点模型的碗扣式脚手架受力性能有限元分析

FEA on bearing behavior of cuplok scaffold based on tri-linear semi-rigid joint model

利用三折线半刚性节点模型,结合碗扣式脚手架竖向承载力足尺试验,对碗扣式脚手架的竖向失稳问题进行了有限元模拟、结果对比和性能分析。模拟中重点考虑碗扣节点的材料非线性和构件的初始几何非线性。结果表明,三折线半刚性节点模型精度可靠,适用于碗扣式脚手架的精细化数值模拟。此外,对影响碗扣式脚手架受力性能的因素进行了研究,包括底端边界条件、碗扣式半刚性节点初始刚度和伸长段长度。研究发现:以上因素对碗扣式脚手架受力性能有不同程度影响,中间立杆离地对承载力影响较大,承载力随碗扣节点初始刚度增大而增大并呈现三段式变化,承载力随伸长段长度增大而减小并呈现两段变化。

The paper adopts and modifies the tri-linear semi-rigid model for simulating a full-scale cuplok scaffold test in a FEM platform. In the presented full-scale test,the bearing capacity,lateral deformation and instability mode were investigated. In FEM simulation, the material nonlinearity due to the semi-rigid joint model and geometric imperfections were taken into account. Numerical results based on the tri-linear semi-rigid model match the experimental observations well. It is shown that the tri-linear semi-rigid joint model is accurate and has potential in refined cuplok scaffolding simulation. Besides,the influences of boundary condition,initial stiffness of semi-rigid joint and jack length are discussed by parametric study. It is shown that centre upright has the most significant influence on the bearing capacity,the bearing capacity gets larger in a tri-linear model as the stiffness of the cuplok rises,while the bearing capacity gets smaller in a two-linear model as the jack length rises. Several recommendations are given for engineering practice.