排序方式: 共有59条查询结果,搜索用时 31 毫秒
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Based on the principle of virtual work, an updated Lagrangian finite element formulation for the geometrical large deformation analysis of galloping of the iced conductor in an overhead transmission line is developed. In numerical simulation, a three-node isoparametric cable element with three translational and one torsional degrees-of-freedom at each node is used to discretize the transmission line. The nonlinear dynamic system equation is solved with the Newmark time integration method and the Newton-Raphson nonlinear iteration. Numerical examples demonstrate the efficiency of the presented method and the developed finite element program. A new possible galloping mode, which may reflect the saturation phenomenon of a nonlinear dynamic system, is discovered under the condition that the lowest order of vertical natural frequency of the transmission line is approximately two times of the horizontal one. 相似文献
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一种有限元-边界元耦合分域算法 总被引:1,自引:0,他引:1
提出了一种有限元-边界元耦合分域算法.该算法将所分析问题的区域分解成有限元和边界元子域,在满足两子域界面上位移和面力协调连续的条件下,通过迭代求解得到问题的解.在迭代求解过程中,引入动态松弛系数,使收敛得以加速.该方法在两子域界面上有限单元结点和边界单元结点的位置相互独立,无需协调一致,对诸如裂纹扩展过程的模拟具有独特的优势.用所提出的耦合算法分析算例,得到的结果与有限元法、边界元法和另一种耦合算法的数值计算结果一致,验证了这种算法的正确性和可行性. 相似文献
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流体饱和两相多孔介质拟静态问题的混合有限元方法 总被引:1,自引:0,他引:1
针对基于混合物理论的两相多孔介质模型,采用Galerkin加权残值有限元法,导出求解所静态问题的基于us-uF-P变量的混合有限元方程,由于系统方程的系数矩阵非定,进而针对该方程组提出了一种失代求解方法,并由分片试验得出节点压力插值函数的阶须低于固体相节点的位移插值函数的阶的结论,算例结果表明,采用基于u2-uF-p变量的混合法计算所得的固体相和流体相速度以及固体相的有效应力与罚方法一致,而压力值的粗度高于罚方法。 相似文献
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裂纹线场分析方法目前已发展成为裂纹弹塑性分析的一种独立方法,这一方法极大地简化了裂纹弹塑性问题的复杂性和数学上的困难,可求出各型裂纹的弹塑性场在裂纹线附近足够精确的解答,但是,以前采用这一方法求解时,均是针对一些具体问题进行的,没有给出裂纹线附近弹塑性分析的一般步骤和匹配方程的一般形式。该文针对理想弹塑性I型平面应力裂纹问题,按线场分析方法,给出了裂纹线附近弹塑性分析一般步骤,并针对一具体问题,给出了求解的过程和结果。 相似文献
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A domain decomposition algorithm coupling the finite element and the boundary element was presented. It essentially involves subdivision of the analyzed domain into sub-regions being independently modeled by two methods, i.e., the finite element method (FEM) and the boundary element method (BEM). The original problem was restored with continuity and equilibrium conditions being satisfied on the interface of the two sub-regions using an iterative algorithm. To speed up the convergence rate of the iterative algorithm, a dynamically changing relaxation parameter during iteration was introduced. An advantage of the proposed algorithm is that the locations of the nodes on the interface of the two sub-domains can be inconsistent. The validity of the algorithm is demonstrated by the consistence of the results of a numerical example obtained by the proposed method and those by the FEM, the BEM and a present finite element-boundary element (FE-BE) coupling method. 相似文献
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用MMX分子力学程序以及分子图形学方法对α-氨基膦酸酯与N-氯乙酰基甘氨酸乙酯反应的机理进行了探讨。结果表明,此类反应热力学因素不起主要作用,动力学因素起主要作用,取代基空间效应是影响反应历程的重要因素。 相似文献