Papers by Keyword: Non-Uniformity

Abstract: The article considers the influence of the surface geometry of a detail on the deposition of coating thickness in the simulation of electroplating processes. The methods for obtaining sets of points describing the surface of a detail are analyzed. Solving the inverse problem (recovering the 3D surface of a detail according to its 2D drawings) is the most promising method. The inverse problem solution is decomposed into simpler geometric problems: input data processing; obtaining primitives; obtaining the desired surface of a detail by applying logical operations to primitives. Mathematical statements are formulated and solution algorithms are proposed for solving these problems. The inverse problem solution is implemented through software. The distribution of the nickel coating thickness is shown for a detail, the surface of which is obtained by solving the inverse problem.

Abstract: In view of the phenomenon that the curved duct in anchorage zone of cable-stayed bridges result in non-uniformity of each of steel strand, we analyzed the position change law of the prestressed steel strand in curved duct. Simulating real bridge design, a simple method was proposed to compute non-uniformity level of prestressed steel strand in the process of tensioning. Results showed that the rearrangement caused the additional length difference result in stress non-uniformity of each steel strand. Because each of steel strand cannot participate in force at the same time, the actual elongation value of the tendon is greater than theoretical value.

Abstract: Hollow cylinder torsional shear test is simulated regarded as a boundary value problem employing a three-dimensional static/dynamic soil-water coupled finite deformation analysis to investigate the influence of the specimen geometries on apparent behavior concerned in practical experiments. 1) A “Perfect path” which means the response of a single three-dimensional element with uniform deformation is calculated to investigate the effect of non-uniformities on the apparent behavior. As can be seen, only the apparent behavior with thinnest wall thickness coincides with the “Perfect path”, which indicates a uniform deformation inside the thinnest specimen; 2) It was found that when the cylinder wall thickness became smaller, the non-uniformity also decreased correspondingly, which can also be seen in the element behaviors of the thickest specimen; 3) Even thought the non-uniformity in different geometries is quite different, there seem to be no significant influence on the apparent behavior. The reason may lie in the extreme constraint conditions, namely displacement control.

Abstract: Taking the air intake pipe in the engine as the target of the research, the software STAR-CDE is adopted to build a three-dimensional simulation model for the air intake pipe in the engine T12V190 with the aim to solve the problems of air input deficiency, Combustion deterioration and performance reduction of one cylinder caused by the non-uniformity. Moreover, the non-uniformity of the flux of air intake of the air intake pipe is mainly studied and analyzed through a calculation on the CFD of the inner flow field of the three dimension of the air intake pipe in the engine T12V190. In addition, a retrofit design with multiple schemes is made based on the cavity structure of the original mold for the air intake pipe. Finally, through a comparison among the three selected designs, a more feasible retrofit designing scheme and a designing thought on the air intake pipe in the engine with directional significance are got.

Abstract: In this paper, for solving the problem of the filling slurry’s segregation which always leads to non-uniform in-situ filling body, an indirect detection method has been developed to test the material components of the backfill based on element conservation principle. Combined with this detection method, an analog simulation flume experiment has been carried out to study the non-uniform characteristic of the backfill. The results show that the strength of the in-situ backfill body with high content cement is in an S-shaped type distribution, whilst the strength of the in-situ backfill body with low content cement is in a linear decreasing distribution. And on the basis of experimental analysis, the strength distribution model of the in-situ backfill body has been built to study a safe and economical backfill design.

Abstract: Shell elements were used to simulate the wide box girder of arch bridge. Different load cases on the arch bridge were calculated and the stress distribution pattern of the wide girder was obtained. The results show that the stresses of the top plate and the bottom plate are non-uniformity along transverse direction at same section, the maximum non-uniformity coefficient of the top plate and the bottom plate are 1.89 and 1.73 respectively. To arch bridge with large ratio of width to length, the transverse stress of girder should not be neglected and the combined stress should be used to determine the structure safety.

Abstract: In order to solve the problem of high non-uniformity of LED display images which is caused by the edges of LED display panel during module splicing, transitional compensation algorithm is proposed by improving the existed correction technique named the correction technique based on CCD. First, introduce the three development stages of the LED display panel. Then, the realization progress of the transitional compensation algorithm is described in detail after elaborating the principle of transitional compensation. Finally, the algorithm is emplaned in a LED video control system to control the LED display panel whose display area is 1280×960, and which is spliced by 30×20 LED modules whose size are 64×32. Experimental results show that this algorithm is able to reduce non-uniformity of LED display images from 29.3% before correcting to 0.95%.

Abstract: For the purposes of correcting the LED display image, a method based on computer simulation is proposed. First, the development of the LED display panel is introduced. Second, analyze the causes of the problem which image in LED display panel has serious high non-uniformity, and introduce the existed correction techniques which are used to reduce the non-uniformity of LED display image. Simultaneously, point out the ground for shortcomings of these techniques. Third, describe the principle of correction method based on computer simulation detail from two steps, which are the luminous collection and luminous copulation. Forth, describe the realization steps of this method in accordance with the third step. Finally, this method is supplied in a LED display panel, whose resolution is 640×480. Experimental results show that this method is able to reduce the non-uniformity of images from 11.06% to 0.98%..

Abstract: The non-uniformity feature of rock joints’ surface profiles is the main influencing factor of the sampling representativeness. In order to analyze the sampling representativeness of rock joints statistically, the joint roughness coefficient (JRC) of 18 pieces of natural slate rock structural plane samples with size from 100mm to 1000mm were measured. The results show that it is necessary to evaluate the representativeness of rock joints in engineering practice due to the large non-uniformity of JRC. The total variation of JRC for different measurement sections, sizes and samples indicates that the sampling representativeness can be evaluated by the average value and the distribution probability of JRC; moreover, the sampling representativeness should be considered the statistical law evaluation of JRC for the concrete size and sample, and offered the accurate standard in changing range.

Abstract: Non-uniformity of the asphalt pavement is one of most important reason for early disease, control of non-uniformity in the production process of asphalt pavement is an important measure to ensure that quality and service life of pavement. Nuclear density gauge (PQI) can be non-destructive, rapid detection of asphalt pavement density. This paper give a research and application on the PQI calibration, testing frequency, the control parameters and evaluation index, and proposes a control method of non-uniformity in asphalt pavement construction with PQI. Asphalt pavement quality control in construction process can use this method. It is important to improve the stability of asphalt pavement quality and reduce the incidence of disease, and also has a certain reference value for establishing the quality control and quality assurance systems.