Papers by Keyword: Three-Dimensional

Abstract: At present, most of the studies of the stability of the formation-cement sheath-casing combination have been mainly based on the plane, and the three-dimensional model established is only one example. There is no systematic study of the influence of physical parameters and process parameters on the stability of the combined body under the three-dimensional model and the action of triaxial crustal stress. Through the establishment of three-dimensional formation-cement sheath-casing linear elastic combination model, we can study the influence of operational parameters (cement sheath pressure, casing cross section pressure, inner casing pressure, ellipticity of borehole, centrality of casing, thickness of cement sheath) by the two interfaces’ Von Mises stress and the total displacement of the combination body. It is pointed out that the pressure of cement sheath, and casing cross section pressure have no effect on the stability of formation, cement sheath and casing; The higher the ellipticity of the borehole, the eccentricity of the casing (position 1, 2) and the thickness of the cement sheath, the higher the stability of the second interface of the cementing; The higher the inner casing pressure and the eccentricity of the casing(position 3), the lower the stability of the second interface of the cementing; The higher the eccentricity of the casing (position 2,3) and the thickness of the cement sheath, the higher the stability of the first interface of the cementing; The higher the inner casing pressure, the eccentricity of the casing (position 1) and the ellipticity of the borehole, the lower the stability of the first interface of the cementing; The higher the eccentricity of the casing (position 2,3) and thickness of the cement sheath, the higher the stability of the casing; The higher the inner casing pressure, the ellipticity of the borehole and the eccentricity of the casing(position 1), the lower the stability of the casing. Through this study, according to the formation stress, the formation physical parameters (elastic modulus, Poisson's ratio, density), optimize the operational parameters, ensure the long-term integrity of the combination.

Abstract: The kinematic (upper bound) method of limit analysis is a powerful technique for evaluating rigorous bounds on limit loads that are often very close to the true limit load. While generalized computational techniques for two-dimensional (e.g., plane strain) problems are well established, methods applicable to three-dimensional problems are relatively underdeveloped and underutilized, due in large part to the cumbersome nature of the calculations for analytical solutions and the large computation times required for numerical approaches. This paper proposes a simple formulation for three-dimensional limit analysis that considers material obeying the Mohr-Coulomb yield condition and collapse mechanisms consisting of sliding rigid blocks separated by planar velocity discontinuities. A key advantage of the approach is its reliance on a minimal number of unknowns, can dramatically reduce processing time. The paper focuses specifically on tetrahedral blocks, although extension to alternative geometries is straightforward. For an arbitrary but fixed arrangement of blocks, the procedure for computing the unknown block velocities that yield the least upper bound is expressed as a second-order cone programming problem that can be easily solved using widely available optimization codes. The paper concludes with a simple example and remarks regarding extensions of the work.

Abstract: This paper demonstrates three-dimensional imaging of threading screw dislocations (TSDs) and threading edge dislocations (TEDs) in 4H-SiC using two-photon-excited photoluminescence (2PPL) band-edge emission. Three-dimensional (3D) images of TSDs and TEDs are successfully obtained as dark contrasts on a bright background of band-edge emission. The intensity inversion of a 2PPL 3D image yields a perspective to visually examine the propagation behavior of dislocations. The tilt angles of TEDs are also measured and shown to correlate with the directions of the extra half planes of TEDs.

Abstract: Through the implementation of algorithm based on B-Rep three-dimensional solid modeling techniques, combination with substation, pole tower, electric transmission line and other electric power facilities, C# is used as the main development language and Microsoft Visual Studio2013 is applied to develop three-dimensional solid modeling software of electric power facilities to serve as pre-processing part of CAE system and provide software technology support for finite element analysis.

Abstract: Large area real terrain modeling is the key technology in visual simulation system. This thesis discusses the terrain modeling technology based on the GeoTIFF data, which transform the GeoTIFF data to DEM using the Global Mapper. And then, the three dimensional terrain models are established through Creator environment, the real terrain modeling is implemented quickly.

Abstract: Wurtzite three-dimensional ZnS nanostructure has been synthesised under low temperature (180°C) via solvothermal method in mixed solvents of ethylenediamine and ethylene glycol. The phase structure, morphology and optical properties have been characterized by X-ray (XRD), scanning electron microscope (SEM) and photoluminescence spectra (PL). Through the change of reaction time and the mixed solvent ratio, the properties of three-dimensional ZnS have been discussed in this paper.

Abstract: For the tightness problem of cooling carrier in high-power three-dimensional system in package, this paper analyzes the tightness problem. First, this paper makes modeling and simulation of cooling carrier in high-power three-dimensional system in package, makes thermal simulation analysis based on existing fluid boundary conditions using ANSYS, gets the temperature of each structure of the cooling carrier in high-power three-dimensional system in package, the fluid temperature, the fluid pressure and other results. Then, based on the results of the thermal simulation analysis as the boundary condition of structural analysis of cooling carrier, this paper gets the stress results at the seals, and analyzes the tightness problem of cooling carrier after the structure simulation. This paper provides a good reference on design of cooling carrier in high-power three-dimensional system in package.

Abstract: Three-dimensional machining procedure models are used for generating three-dimensional process model and process planning that support machining. It can be realized through extracting information of three-dimensional design model. The consistency of data and visualization of machining can be improved using the technologies for parts, which are compared with the current two-dimensional technology. The key technologies and framework for construction of three-dimensional machining procedure model based definition are researched.

Abstract: The blending effect of design pattern of five-surface plane developed drawing is important to the design pattern. The blending of three-dimensional pattern design can realize the automation of pattern design. The target pattern design of air brushing is based on the square design picture. Therefore, the effect is bad, especially in the edges between surfaces. Edge processing method is developed to solve this problem. The pixels are compressed in accordance with the image pixel compression method. According to the processing steps, the computer programming is performed. The results shows that, the floral drawing in the blending design figure can extend to the adjacent surfaces naturally, and the blending effect is great after the three-dimensional blending perform.

Abstract: A novel three-dimensional (3D) convex hull method is proposed, which is called dimensionality reduction convex hull method (DRCH).Through having 3d point set map to 2d plane, most initial 3D points in the convex hull are removed. Then, the remaining points are to generate 3D convex hull using any convex hull algorithm. The experiment demonstrates 3D DRCH is faster than general 3D convex hull algorithms. Its time complexity is O(r log r), where r is the number of points not in the hull. And DRCH can be generalized to higher-dimensional problems.