钢-混凝土混合框架结构多尺度分析及其建模方法

多尺度计算是保证计算精度的同时最大限度降低计算代价的有效途径,在众多学科领域和工程问题中都得到了应用.在结构有限元多尺度分析领域,要解决的一个关键问题是如何实现局部微观模型与宏观结构模型之间的共同工作.为实现精细有限元模型在植入宏观结构模型时不同尺度模型界面的变形协调,提出有限元微观模型与宏观模型的界面连接方法,给出了轴向、横向和转角的约束方程.通过编制用户子程序,使该方法在有限元软件中得以实现,并通过简单的圆柱筒算例,对界面连接的合理性进行了验证.最后基于多尺度建模方法和复杂混合结构节点的精细模型,给出了钢-混凝土混合框架结构多尺度弹塑性时程分析的应用实例,结果表明多尺度计算可较好模拟节点的复杂边界条件.本文建议的界面连接方法可有效实现不同尺度模型界面的变形协调,为工程结构进行多尺度提供了条件.

Multi-scale finite element modeling and its application in the analysis of a steel-concrete hybrid frame

As an effective process to obtain appropriate balance between accuracy requirements and calculation workloads, multi-scale calculation has been introduced into many research fields as well as different engineering practices. In the field of structural multi-scale finite element analysis, an important research problem is how to make the local microscopic model and structural macroscopic model work together. To accomplish a reliable interface between microscopic model and macroscopic model, a methodology was proposed and its constraint equations of deformations including axial deformation, transverse deformation and rotation were presented. With a user-defined subroutine, the multi-scale modeling was realized in commercial finite element software and a simple tube was calculated to verify the methodology. Based on an accurate microscopic column-to-beam connection model validated by test, elasto-plastic multi-scale analysis of a steel-concrete hybrid frame was carried out and the results show that multi-scale calculation can simulated the complex boundary condition of this connection well. The proposed methodology meets the deformation compatibility well at the interface between different-scale models and is applicable in engineering application.