Advanced Materials Research Vol. 549

Abstract: Because of the weak borehole sealing and inadequate use of the initial free face, the higher investment and unsatisfactory blasting effect still exist in the mine tunnel excavation blasting. In order to improve the blasting effect of drifting, on the basis of a discussion on blasting mechanisms, the author take Xinhong Mine fine sandstone roadway for example, select reasonable blasting parameters and determine the proper cutting form. So that the efficiencies of blasting and excavation have been increased greatly, and good economic results has been achieved.

Abstract: Seam tracking is significant to obtain good welding quality. Aiming at establishing a model to detect and calculate the seam tracking offset during high-power fiber laser welding of Type 304 austenitic stainless steel plate butt joint welding, an infrared sensitive high-speed camera arranged off-axis orientation of laser beam was applied to capture the dynamic thermal images of molten pool. Through analyzing the infrared image, the actual position of the workpiece gap in the image was obtained. Least squares method was used to determine the precise position of the actual workpiece gap. A model that calculated the deviations between the workpiece gap and the laser beam was deduced. Also, the least squares method was used to fit the workpiece gap curve equation. The coordinate transformation technology was used and the welding seam equation was established. A linear model was obtained to detect the deviations between the workpiece gap and the welding seam. The welding experiments confirmed that the proposed welding seam equation was effective.

Abstract: Reverse engineering has become an important tool for CAD model construction from the data points, measured by a coordinate measuring machine (CMM), of an existing part. However, due to special structure and complex topology relation, obtaining full surface data of a prototype is not an easy thing and should carry out complex data process procedure to get global model. The paper presents a method for pre-processing data points for curve fitting in reverse engineering. The proposed method has been developed to process the measured data points before fitting into a B-spline form. The method is implemented and used for a practical application in reverse engineering. The result of the reconstruction proves the viability of the proposed method for integration with current commercial CAD systems.

Abstract: In order to guarantee the steel bar quality, we describe the category of steel bar surface defects in details. Generally, there are about two main categories of steel bar surface defects which include linear and area-like defects. Secondly, the characteristics of the steel bar surface image are analyzed at large. Both of them support a foundation for the future inspection of steel bar surface quality.

Abstract: According to the requirements to reuse the design resources such as the three-dimensional parametric part models in the new products development process, the key issue to develop the 3D part library which its content can be expanded and recombined are researched based on the Part with the character of standardization and universal. The paper provid the object and the system structure of this 3D part library firstly. Then, the method to classify the Part data and the corresponding storage way are discussed according to the function of the classified Part data.Finally the method to develop management program of this 3D Part library is discussed based on the Pro/E and Access. The method provided in the paper can be a general way to develop 3D part library for different application field.

Abstract: Decisive factors of the product design, such as shape, color, materials, structure, function, man-machine relationship, cannot be quantified, or they are "gray" in nature. This paper first applies the gray statistical methods to analyze the data of the indicators. Due to the difficulty in determining the index weight in the evaluation, we consolidated the indicators based on DEA Informational models, and concluded comprehensive results for various designs.

Abstract: A high level of oxygen in boiler supply water would lead to oxidation corrosion of the boiler tubes. Reduction of the boiler tube thickness will affect its service life even result in such serious accidents as tube explosion. In S oil-field, a combining measure of physical and chemical methods were adopted to improve deaerator technology. A relatively complete ground deaeration process is formed. The deaeration system consists of water ring vaccum pump, deaeration tank, booster pump, circulating tank, etc. First softened water processed by softener would flow through 80 mesh stainless steel screen filter. Then in high vacuum deaeration tank, the water will be ejected in a spray due to the eddying flow of the nozzles and size of the droplet can reach 30 micrometer. Oxygen partial pressure in the tank is in a minimal level so that dissolved oxygen in the water-drops can be released. The steam and released oxygen will be sent to circulating tank for recycling. Deoxidation rate of the process can be above 95% and residual dissolved oxygen can be removed by chemicals. So the boiler supply water can meet technical requirements. The deaeration system has a good application in boiler supply water deaeration in S oil-field. Practical application shows the deaeration system has characteristics of stable performance, mainly maintenance-free, and good adaptability to some poor-quality water. So the deaeration system has a good promotion value.

Abstract: The ignition process of NEPE propellant by a CO₂ laser ignition system has been investigated experimentally. The effect of laser heat flux density on the ignition delay time of NEPE propellant was examined. The ignition delay time of NEPE propellant was decreased along with the increase of laser heat flux density. The effect of ignition heat flux density on ignition delay time decreases when the laser heat flux density is more than 290 W/cm². This heat flux density value can be used as igniter design reference value. The ignition delay time increases dramatically along with the decrease of laser heat flux density when the laser heat flux density is lower.

Abstract: Mechanical Design Handbook oriented standard part library system of jaw clutches is developed based on SolidWorks. The system consists of three elements, namely a dimension parameter database, a user interface, and a modeling function module. The jaw clutch dimension parameter database is designed based on national standards. According to designers’ thinking habit, a visual user interface is customized to make easy use of the dimension parameter database. The data relationship between the modeling function module and dimension parameter database is established by using parametric program driven method. The jaw clutch standard part library with characteristics of friendly user interface and expansible database is easy to use. The approach adopted in the paper can be used to develop other general 3D standard part library on SolidWorks.

Abstract: Rapid prototyping has quickly grown in use and importance in industrial applications during the past decade. Rapid prototyping, though a relatively new discipline, has proven to be a valuable tool in the reduction of the time and cost associated with developing new products. This paper summaries the working principle and compares the application fields, machining cost and process parameters for four typical RP technology. The author discusses the significant performance for modern industry, analyses the merits and faults and indicates the development object for RP technology.