基于A,φ-A法和库伦规范,推导了导体区域和非导体区域的有限元方程及自由空间的边界元方程,通过引入交界面条件,实现了将边界元矩阵等效为有限元矩阵求解的有限元-边界元耦合法(finite element and boundary element coupling method,FE...基于A,φ-A法和库伦规范,推导了导体区域和非导体区域的有限元方程及自由空间的边界元方程,通过引入交界面条件,实现了将边界元矩阵等效为有限元矩阵求解的有限元-边界元耦合法(finite element and boundary element coupling method,FE-BECM)。将FE-BECM应用于TEAM-7问题的计算,验证了该方法处理开域涡流问题的有效性。当FE-BECM应用于运动导体涡流场(moving conductor eddy current,MCEC)问题时,用有限元离散源电流区域和运动部件,用边界元离散自由空间并关联相互独立的有限元区域。该方法克服了常规有限元法使用1套网格处理运动问题所遇到的麻烦。使用有限元-边界元耦合法对单级线圈炮问题进行了计算,验证了算法处理运动导体涡流场问题的有效性。展开更多
The data information transfer and time marching strategies between computational fluid dynamics (CFD) and computational structural dynamics (CSD) play crucial roles on the aeroelastic analysis in a time domain. An...The data information transfer and time marching strategies between computational fluid dynamics (CFD) and computational structural dynamics (CSD) play crucial roles on the aeroelastic analysis in a time domain. An improved CFD/CSD coupled system is designed, including an interpolation method and an improved loosely coupled algorithm. The interpolation method based on boundary element method (BEM) is developed to transfer aerodynamic loads and structural displacements between CFD and CSD grid systems, it can be universally used in fluid structural interaction solution by keeping energy conservation. The improved loosely coupled algo-rithm is designed, thus it improves the computational accuracy and efficiency. The new interface is performed on the two-dimensional (2-D) extrapolation and the aeroelastie response of AGARD445.6 wing. Results show that the improved interface has a superior accuracy.展开更多
With the rural concealed communication cable as the study object, the shielding effectiveness of different slot shapes was analyzed by using LBEM (linear boundary element method). The engineering example results sho...With the rural concealed communication cable as the study object, the shielding effectiveness of different slot shapes was analyzed by using LBEM (linear boundary element method). The engineering example results showed that for twocore shielded cable, the coupling capacitance of trapezoid slots (asymmetric and symmetric) changed the most, followed by rectangular slots (asymmetric and symmetric), and the changes of wedge slots were the smallest, but the change tenden- cies were consistent. In addition, with the increase of slot width of different slots, the coupling capacitance of tow-cored shielded cable showed small change.展开更多
This work deals with the analysis of soil-structure interaction modeling of pipeline problems in static behavior using the coupling between FEM (finite element method) and BEM (boundary element method). The repres...This work deals with the analysis of soil-structure interaction modeling of pipeline problems in static behavior using the coupling between FEM (finite element method) and BEM (boundary element method). The representation of the pipe is made by MEF using one fmite element in the cylindrical panel formulated from the theory of equivalent discrete layers (Layerwise theory), proposed by J. N. Reddy. The soil is represented by elastic continum infimite or semi-infinite and modeled using boundary elements with special curved surface, associated with cylindrical panel used to represent the soil-structure interaction within the soil, especially at the contact surface with the pipe.展开更多
文摘基于A,φ-A法和库伦规范,推导了导体区域和非导体区域的有限元方程及自由空间的边界元方程,通过引入交界面条件,实现了将边界元矩阵等效为有限元矩阵求解的有限元-边界元耦合法(finite element and boundary element coupling method,FE-BECM)。将FE-BECM应用于TEAM-7问题的计算,验证了该方法处理开域涡流问题的有效性。当FE-BECM应用于运动导体涡流场(moving conductor eddy current,MCEC)问题时,用有限元离散源电流区域和运动部件,用边界元离散自由空间并关联相互独立的有限元区域。该方法克服了常规有限元法使用1套网格处理运动问题所遇到的麻烦。使用有限元-边界元耦合法对单级线圈炮问题进行了计算,验证了算法处理运动导体涡流场问题的有效性。
基金Supported by the Ph.D.Program Foundation of Ministry of Education of China (20070699054)~~
文摘The data information transfer and time marching strategies between computational fluid dynamics (CFD) and computational structural dynamics (CSD) play crucial roles on the aeroelastic analysis in a time domain. An improved CFD/CSD coupled system is designed, including an interpolation method and an improved loosely coupled algorithm. The interpolation method based on boundary element method (BEM) is developed to transfer aerodynamic loads and structural displacements between CFD and CSD grid systems, it can be universally used in fluid structural interaction solution by keeping energy conservation. The improved loosely coupled algo-rithm is designed, thus it improves the computational accuracy and efficiency. The new interface is performed on the two-dimensional (2-D) extrapolation and the aeroelastie response of AGARD445.6 wing. Results show that the improved interface has a superior accuracy.
基金Supported by the Science and Technology Program of the Education Department of Shaanxi Provincial Government(09JK378)the Key Scientific Research Fund of Shaanxi University of Technology(SLGKY12-02)~~
文摘With the rural concealed communication cable as the study object, the shielding effectiveness of different slot shapes was analyzed by using LBEM (linear boundary element method). The engineering example results showed that for twocore shielded cable, the coupling capacitance of trapezoid slots (asymmetric and symmetric) changed the most, followed by rectangular slots (asymmetric and symmetric), and the changes of wedge slots were the smallest, but the change tenden- cies were consistent. In addition, with the increase of slot width of different slots, the coupling capacitance of tow-cored shielded cable showed small change.
文摘This work deals with the analysis of soil-structure interaction modeling of pipeline problems in static behavior using the coupling between FEM (finite element method) and BEM (boundary element method). The representation of the pipe is made by MEF using one fmite element in the cylindrical panel formulated from the theory of equivalent discrete layers (Layerwise theory), proposed by J. N. Reddy. The soil is represented by elastic continum infimite or semi-infinite and modeled using boundary elements with special curved surface, associated with cylindrical panel used to represent the soil-structure interaction within the soil, especially at the contact surface with the pipe.