Papers by Keyword: Analysis

Abstract: A new type of machining method called half-spread-out helix modified roll is used to carry out numerical control machining and simulation of spiral bevel gears in this paper. The transformation from traditional machine tool adjustment parameters into processing input parameters of five-axis CNC machining center was realized. The simulated gear model of this machining method is obtained, and the coordinates of its tooth surface points are compared with points coordinates of theoretical tooth surface which are generated according to the traditional machining method. From the comparison, the correctness of this numerical control machining model is verified.

Abstract: The task of tolerance analysis usually addresses the question of the mechanical mountability of an assembly. We extend this viewpoint when talking about directional control valves in a crossdomain tolerance analysis; an analysis whose task is to determine the possible variation in the key product characteristics induced by a specific tolerance concept. As the available information about the noise factors to be toleranced is almost always imperfect generalised methods for their representation and the propagation of their impact on the key product characteristics are required. In this study the capabilities and potentials of belief and plausibility measures as well as fuzzy random variables are compared to traditional worst-case and statistical tolerance analysis.

Abstract: The article presents a methodology for expenses optimization in the implementation of measures to address the critical ecological situation in the Azov Sea area, describes the location of the unique natural site - the Sea of Azov, describes anthropogenic factors affecting the bio-productivity of valuable fish species, examines environmental protection measures and shows necessity of their practical application.

Abstract: The natural rubber compound of each layer of solid tire had determined the mechanical properties in tension. It was found that the stress-strain relation of each material tire layer was fitted very well with the Ogden constitutive model. The R² which was 0.986, 0.996 and 0.985 represented the certain curve fitting on the internal, middle and tread layer of solid tire, respectively. Subsequently, the Ogden model was implemented in the finite element model of the rubber specimen and solid tire. The finite element analysis results obtained an average error of 18.00% and 14.63% for the specimen and solid tire model by comparing to the physical experiment, respectively. Particularly, the mechanical properties of the natural compounds could be used to predict the ultimate compression load for the solid tire failure.

Abstract: Abstract: The paper is focused on a system of investigation of hidden parts of historical buildings as footing masonry and subsoil affecting significantly their technical conditions and stability. These impacts are mostly difficult to identify in time and there are often indirect producing differential settlement resulting in development of systems of cracks in the building masonry. Reliable analysis of the building supporting system shall precede any remedial actions or reconstructions. If the demonstration of the above negative impacts on the building becomes visible, it can indicate our late entry in to solving the problems with deterioration of the foundation system. Investigation boring and instrumentation of boreholes for high accuracy 3D displacement monitoring with local levelling system is presented in the paper illustrated by an example of one baroque church of the Broumov group of churches. This activity was followed by analyses of building stones and determination of degree of the footing masonry and subsoil deterioration together with careful input data for numeric modelling estimation.

Abstract: A research procedure and configuration of a welded sample are proposed to explore properties of welded metal using thermal microscopy facilities.

Abstract: With the growth in wide bandgap (WBG) semiconductors, specifically Silicon Carbide (SiC), the technology has matured enough to highlight a need to understand the drivers of manufacturing cost, regional manufacturing costs, and plant location decisions. Further, ongoing research and investment, necessitates analytical analysis to help inform development of wide bandgap technologies. The paper explores the anticipated device, module, and motor drive cost at volume manufacturing. It additional outlines the current regional contributors to the supply chain and proposes how the base models can be used to evaluate the cost reduction potential of proposed research advances.

Abstract: The leachate from landfills is considered as a great danger to the environment and human health. This danger is represented in its toxic components. The major purpose of this project is how to get rid of the toxic materials by a collection of sediments, scrap rubber and geotextile layers. Ten (10) cells with different compositions were used in this process, and the physicochemical analysis were made on water resulted from filtration. And permeability test on all cells. The results show that the physicochemical factors reduce with the increase of thickness of sediment layer. The physicochemical factors of water resulted from the cells which contain scrap rubber with dimensions of 0.2mm are fewer than the ones with dimensions of 4mm. The permeability factor rise in all the cells with the increase of scrap rubber layer thickness of both types.Cell 5 with no scrap rubber gave better results in physicochemical factors but weak results in permeability factor. Cell 4 gave good results in both physicochemical and permeability factors

Abstract: Rocket motors are used worldwide in both upper and booster stages.Solid rockets can provide high thrust for relatively low cost. Considering the large size of solid motors, these motors are to be designed as segmented motor cases. Segmented motor cases have to be joined by segment joint. Segment joint with tongue and groove configuration provides performance reliability in effective sealing of joints. A tongue-and-groove arrangement employs a pressure-energized metal seal which expands radially when the cylinders are internally pressurized. The radial expansion enhances the sealing effect of the metal seal between the tongue and the groove. Metal end rings welded to the shell motor cases and shear pins for the final assembly provides the sealing. The load sharing among the pins depends on the presence of the slit in a ring, whole & pin dimensional clearances, internal pressure and friction between the metal end rings. Structural analysis of a discontinuous metallic segment ring and shear pins iscarried out in this study. Structural analysis is based on detailed solid model for the segment joint. The load augmentation in the shear pin near the discontinuity is worked out based on a load augmentation factor derived out of FE analysis. The study further extended to a deviation in a nearby hole / pin combination at the vicinity of the discontinuity and is presented in this paper.

Abstract: Laser bonding welding test of the lap joint between steel and Al was conducted. The microstructure analysis is carried out by means of metallographic microscope, which provides an important theoretical and experimental basis for the popularization and application of laser welding of steel / aluminum dissimilar metal structures. The results showed that under the conditions of 1650W laser power, 35m/s welding speed, +3mm defocus amount and 25L/min flow rate of Ar as the protective gas, there are no cracks, pores and inclusions in the weld zone. The fusion line is smooth and smooth. Under the conditions of 1650W laser power, 38m/s welding speed, +3mm defocus amount and 25L/min flow rate of Ar as the protective gas, the overall appearance of the weld zone of the laser welding joint, there are serious cracks, pores and other defects in the weld area. In the P=1680W, V=35mm/s, f=+1mm, q=20L/min, the crystal structure appeared, in the process of cooling, the crack expands and forms a radial shape under the action of internal stress.