摘要
目前国内很多重要的混凝土桥梁具有大跨、超宽的特点。结构的空间受力行为明显,从而导致混凝土的徐变效应更加复杂,一维杆系结构的徐变分析方法局限性凸显。固-壳元是一种实体退化的壳单元,兼具实体单元便于几何描述和壳单元简化结构模型的优点,适合桥梁结构的有限元建模。以固-壳元为基础,采用粘弹性理论考虑混凝土的徐变效应,结合我国04版桥梁规范中的徐变模型,拟合基于粘弹性理论的广义Maxwell模型的参数,推导了固-壳元的粘弹性本构关系,并应用于混凝土的三维徐变分析。数值分析表明,所提出的方法行之有效,受力复杂的混凝土结构有必要进行三维徐变分析。
Long span and super width are the basic characteristics of a number of bridges in China nowadays. The behavior of these structures is obviously spatial, which leads to complicated creep effect in concrete. Precise results are usually unavailable when using 1-D finite element model due to its limitation. Solid-shell element is a solid degenerated shell element, which combines advantages of both convenient geometric description for solid element and simple model for shell element. Based on solid-shell element, the creep characteristics of concrete were taken into consideration by employing the generalized Maxwell viscoelastic model. With the creep model provided in China Code of 2004 Highway P. C. Bridge, the parameters of viscoelastic model were fitted. The viscoelastic constitutive relationship of solid-shell element was derived. Numerical examples showed the validity and efficiency of the proposed method and the necessity of 3-D creep analysis for concrete structures under complicated loading.
出处
《结构工程师》
北大核心
2012年第4期45-50,共6页
Structural Engineers
关键词
桥梁工程
徐变分析
混凝土结构
粘弹性理论
固-壳元
bridge engineering, creep analysis, concrete structure, viscoelasticity theory, solid-shell element
