Search

Abstract: Condensation technique of degree of freedom is firstly proposed to improve the computational efficiency of meshfree method with Galerkin weak form. In present method, scattered nodes without connectivity are divided into several subsets by cells with arbitrary shape. The local discrete equations are established over each cell by using moving kriging interpolation, in which the nodes that located in the cell are used for approximation. Then, the condensation technique can be introduced into the local discrete equations by transferring equations of inner nodes to equations of boundary nodes based on cell. In the scheme of present method, the calculation of each cell is carried out by meshfree method with Galerkin weak form, and local search is implemented in interpolation. Numerical examples show that the present method has high computational efficiency and convergence, and good accuracy is also obtained. [Copyright &y& Elsevier]

The Horizontal Reactive Media Treatment (HRX) well is a novel technology for in situ treatment of contaminated groundwater. The most significant technical performance risk associated with field-scale implementation of the HRX well is the potential for water to bypass the well untreated. Therefore, the groundwater capture simulation plays a very important role in the design of the HRX well. We build a model based on a cell-based smoothed radial point interpolation method (CS-RPIM) for simulating groundwater flow captured by the HRX well in both 3D test pit pilot scale and field scale. This method is compared with the finite element method and measured values. Capture width and groundwater velocity obtained by CS-RPIM are consistent with the measured values. We further develop MATLAB software modules to analyze the effects of the hydraulic conductivities, dimension of well and other parameters on the groundwater capture zone, velocity and residence time in the reactive media. The results show that increase of well diameter has a significant effect on enlargement of the capture zone and the extension of media treatment time. When well diameter increases by 100%, horizontal and vertical capture width increase by 57% and 50% respectively, and media treatment time can be extended by 68%. • A realistic 3D model was built for simulating groundwater captured by the HRX well. • The simulation results outperform FEM or the average capture width formula results. • MATLAB software modules are developed for hydraulic capture zone simulation. • Impact of various factors on the capture zone, groundwater flow velocity and treatment time are analyzed. [ABSTRACT FROM AUTHOR]

Thin plate problem has been receiving much interest due to its wide application in engineering. In this paper, a novel thin plate element theory is proposed based on a continuity re-relaxed technique to avoid the high continuity requirement for thin plate formulation which needs the high computation cost. The problem is first discretized into a set of background cells with field nodes, and only deflection field is treated as the field variable. On top of the background cells, the integration domains are further formed. The curvatures over integration domains are restructured through the divergence theorem, and the continuity requirement of the trial deflection function for thin plate problems can be re-relaxed. The Galerkin weak form is then used to create the discretized system equations. The curvatures in the integration domains are constant, and the stiffness matrix of the system can be computed directly without numerical integration. The rotational essential boundary conditions are imposed in the process of curvature field construction. Some numerical examples are computed using the RPIM approximation function. The excellent results demonstrate the efficiency of the proposed method. [ABSTRACT FROM AUTHOR]