Applied Mechanics and Materials Vols. 34-35

Abstract: Many studies have been made for years on dimensions of pneumatic nozzle. To output same blowing force, the supply pressure could be reduced by decreasing the ratio of length to diameter of nozzle. The friction between high speed air and pipe wall would be reduced if the nozzle is designed to be converging shape comparing with straight shape. But the volume flow and pressure, discussed in these studies, do not describe energy loss of the blowing system directly. Pneumatic power is an innovative principle to estimate pneumatic system’s energy consumption directly. Based on the principle, the supply pressure of air blowing system is a critical parameter concerning energy consumption and blowing force. In the experiment, the air blowing system is supplied by a compressor and an air blower respectively. The pressure of air from the compressor is times higher than air blower. A comparison is preformed to the two systems about energy consumption and blowing force. From the result, the air blowing system with air blower consumes less energy than with compressor. This study provides theoretical basis for designing energy-saving air blowing system.

Abstract: In this paper, the present situation of maintenance for heavy duty caterpillar engines was introduced. Based on the maintenance shortcoming of heavy duty caterpillar engines, the remanufacturing technology of armored equipment engines was put forward and discussed preliminary. And the difference between remanufacturing and maintenance for equipment diesel engines are summarized. Then new and novel remanufacturing technology was studied and applied on the engine key parts to prolong its service life. After the application of remanufacturing technology, many worn and waste parts can be reused which can save a lot of resource for our nation. It meet the needs of development tactic requirement for saving resource and decrease contamination emissions.

Abstract: Multi-element CrTiAlN coatings are deposited onto YT14 cemented carbide milling cutter by magnetron sputtering in an Ar+N2 mixture. The nano-indenter, scanning electron microscopy, X-ray diffraction and Rockwell indentations were used to investigate the mechanical property, microstructure and adhesion strength of CrTiAlN coatings. And the tribological properties and dry cutting performance of the CrTiAlN coatings were compared with TiN and TiAlN coatings. The experimental results showed that the phase structures of the composite films include Cr, CrN, Cr2N and TiN phases. And the surface crystal grain of CrTiAlN coatings is relative small and the section structure of CrTiAlN coatings was columns crystal structure. It showed better for CrTiAlN coatings on nano-hardness and adhesion compared with TiN and TiAlN coatings. And the friction coefficient of above three kind coatings was about 0.12-0.15. The friction coefficient and wear volume of CrTiAlN coatings appeared lowest among these three kind coatings. Dry cutting experimental results showed that the sequence of cutting life for these coated tools were CrTiAlN＞TiAlN＞TiN.

Abstract: Based on the amount of tool overhang under different high speed machining experiment, the overhang length on the high speed impact of cutting force in milling process is studies. On the basis, the proposed tool overhang and optimum program are proposed in high speed milling, through the rational use of tools to improve processing capacity of the tool.

Abstract: Knowledge flow reflects the knowledge level cooperation in supply chain. As asset of an organization, structure capital is one of the most important factors that influence and represent the competitiveness of the supply chain. The relationship between structure capital and knowledge flow is analyzed. The analysis based on structural modeling on key factors that affect the flow of knowledge shows that organizational structure and knowledge gap, as the basic factors, could affect the efficiency of knowledge flow.

Abstract: Design and implementation of data interchange platform is an important issue in earthquake precursory industry, which adapts to extensive observatory networks and diverse observatory programs. However, it is a difficult problem since the data managed are likely to inefficient. Finding proper solutions to the aggregation, storage, and distribution of collected data is emergent. In this paper, we designed an efficient data interchange platform, which based on current grid technology, and the distributed database copying, for switching data over multilevel. Offered the appropriate equipment simulator, experimental results show that data interchange platform is more efficient in the earthquake precursory environment.

Abstract: The main objective of the present research is to find the influence of process parameters on the state variables (i.e., surface roughness and material removal rate) in Wire Electrical Discharge Machining (WEDM) of Titanium Diboride (TiB2) nanocomposite ceramics. This work adopted an L32 orthogonal array based on Taguchi method for design of experiments. Statistically evaluating the obtained data is carried out by using the analysis of variance, signal to noise and artificial neural network techniques. Then, the effects of process parameters on the surface roughness and material removal rate are studied. Finally, the Multilayer Perceptron (MLP) neural network is used to model the WEDM of TiB2 nanocomposite ceramic. The obtained results have demonstrated very good modeling capacity of the proposed neural network. Furthermore, analyses have appropriately presented the influence of process parameters on state variables.

Abstract: The dynamic fracture behavior of PVB laminated glass during impact has been studied by both theoretic and finite element approaches. To make the analysis of cracking on PVB laminated glass more accurate and direct, high-speed photography method is introduced in this paper. Different crack patterns as well as their sequences of appearance are visualized. Finally, typical crack is measured in order to obtain important fracture characteristics such as crack velocity and acceleration.

Abstract: In order to fully understanding the distribution of residual stress after riveting and the relationship between residual stress and riveting process parameters during riveting, Finite Element Method was used to establish a riveting model. Quasi-static method to solve the convergence difficulties was adopted in riveting process. The riveting process was divided into six stages according to the stress versus time curves. The relationship of residual stress with rivet length and rivet hole clearance were established. The results show numerical simulation is effective for riveting process and can make a construction for the practical riveting.

Abstract: Cold rolling precision forming process of spline is one of the high-efficiency, precision and non-chip forming advanced manufacturing technologies. It has the characteristics such as high forming efficiency, energy-saving, low material consumption and better forming properties of components. The process and principle of involute spline cold rolling precision forming was analyzed. A measuring and testing system for the force and energy parameters in the forming process was set up, and the real-time variation curves of the torque moment of the spindle and the radial feeding force were obtained. Also, the influencing rules of process parameters on the maximum radial feeding force and spindle torque were investigated. Finally, Precision forming experiments of involute spline cold rolling were carried out with optimized parameters. Precision measuring and hardness testing of the tooth outline section shows that the components obtained by the experiments were free of defects. Compared with the spline components obtained from conventional cutting process, the hardness and wear ability was greatly improved, which is suitable for the requirement of application.