吴庆雄, 陈宝春, 韦建刚. 钢管混凝土结构材料非线性的一种有限元分析方法[J]. 工程力学, 2008, 25(6): 68-074.
引用本文: 吴庆雄, 陈宝春, 韦建刚. 钢管混凝土结构材料非线性的一种有限元分析方法[J]. 工程力学, 2008, 25(6): 68-074.
WU Qing-xiong, CHEN Bao-chun, WEI Jian-gang. A FINITE ELEMENT METHOD FOR ANALYZING MATERIAL NONLINEARITY OF CONCRETE-FILLED STEEL TUBULAR STRUCTURES[J]. Engineering Mechanics, 2008, 25(6): 68-074.
Citation: WU Qing-xiong, CHEN Bao-chun, WEI Jian-gang. A FINITE ELEMENT METHOD FOR ANALYZING MATERIAL NONLINEARITY OF CONCRETE-FILLED STEEL TUBULAR STRUCTURES[J]. Engineering Mechanics, 2008, 25(6): 68-074.

钢管混凝土结构材料非线性的一种有限元分析方法

A FINITE ELEMENT METHOD FOR ANALYZING MATERIAL NONLINEARITY OF CONCRETE-FILLED STEEL TUBULAR STRUCTURES

  • 摘要: 为了更简单地考虑梁单元的材料非线性受力性能,把断面广义力和广义应变的概念运用于单元分析中,将单元的弹塑性刚度矩阵分离为弹性刚度矩阵和塑性刚度矩阵。这样,梁单元的变形可以由弹性变形和塑性变形简单地迭加,结构内力可通过弹性应变能的斜率(弹性刚度矩阵)与位移的乘积求得,从而在增量-迭代计算时可较准确且较快地计算出结构变形后的不平衡力。应用这一计算方法,推导了基于纤维模型的三维梁单元的钢管混凝土结构的有限元基本公式,并将其植入能考虑几何非线性的三维梁单元非线性计算程序NL_Beam3D中以计算结构的双重非线性问题。算例分析表明该方法和程序能较准确地反映钢管混凝土结构的双重非线性特性。

     

    Abstract: Applying generalized force and strain into element analysis, the elastic-plastic stiffness matrix is readily separated into elastic and plastic stiffness matrices in which the material nonlinearity of a beam element are taken into account. The total deformation of the beam element can be accordingly obtained by imposing plastic deformation on elastic deformation, and the internal force can be obtained by multiplying the slope of elastic strain energy (elastic stiffness matrix) with the deformation, so the unbalanced forces after deformation can be calculated more quickly and accurately during iterative analysis. Based on the above-mentioned procedure and so called fiber-model beam element, the primary finite element formula is derived for concrete filled steel tubular structures. This formula is implemented in a geometrically nonlinear finite element analysis computer program NL_Beam3D based on the 3-D beam element, to solve dual-nonlinearity problem. The proposed method and procedure are verified in a case to describe nonlinear behaviors of the concrete filled steel tubular structure accurately.

     

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