Advanced Materials Research Vols. 443-444

Abstract: The 3D finite element model of CAKxxx CNC machine tool is established and the static/dynamic characteristics of the machine tool are analyzed with finite element method when the influence of the linear rolling guide (LRG) joint is considered or neglected. The lowest five natural frequencies and vibration modal shapes are obtained in both cases. It shows that when considering the influence of the LRG joint, each of the lowest five natural frequencies is 14 Hz smaller than the results of neglecting the influence, and the vibration modal shapes are more stable. The modal experiment shows that the results of considering the influence of the LRG joint are closer to the actual situation. It also proves that LRG joint has great influence on the dynamic characteristic of the machine tool. It provides an important reference for accurate modeling and dynamic design of machine tool.

Abstract: In China, it is fact that porous concrete base has been used in the construction of asphalt pavement in recent years because porous concrete base has good performance. However, Reasonable design method has not been put forward so far. Therefore, it is necessary to analyze load stress and thermal stress of asphalt pavement which includes porous concrete base in order to put forward theoretical basis for pavement design method. In the paper, three–dimension finite element model of asphalt pavement, which includes porous concrete base and asphalt surface, is created for the purpose of studying load stress and thermal stress of porous concrete base in asphalt pavement. Based on numerical method of three–dimension finite element model, finite element software, such as ANSYS, is employed to study load stress and thermal stress of porous concrete base in asphalt pavement. After that, the effect of different factors on stress is studied, and the factors include thickness of surface, thickness of base and ratio of base’s modulus to foundation’s modulus. Finally, calculation results for stress are compared with each other, and it shows that load stress of porous concrete base decreases with increase of base’s thickness, while thermal stress of porous concrete base increases with increase of base’s thickness. Load stress and thermal stress of porous concrete base decrease with increase of surface’s thickness. Load stress and thermal stress of porous concrete base increase with increase of ratio of base’s modulus to foundation’s modulus.

Abstract: In the field of asphalt pavement, the study has shown that porous concrete base has a good performance of drainage capacity. When porous concrete is used in asphalt pavement, problem of water damage for asphalt pavement can be settled effectively. Because of that, more and more porous concrete base have been applied to asphalt pavement construction in recent years. As a matter of fact, it is necessary to do mechanical analysis for asphalt surface, which is located in the middle of porous concrete base’s transverse contraction joint, in order to put forward theoretical basis for asphalt surface design. In the paper, three–dimension finite element model of asphalt pavement, which includes transverse contraction joint of porous concrete base and asphalt surface, is created for the aim of doing mechanical analysis of asphalt surface which is located in transverse contraction joint of porous concrete base. Based on numerical method, finite element software, such as ANSYS, is employed to do mechanical analysis for asphalt surface which is located in transverse contraction joint of porous concrete base of asphalt pavement. Mechanical analysis show that load stress is compressive stress, and maximum shearing stress, which is caused by load, is evident in asphalt surface which is located in transverse contraction joint of porous concrete base of asphalt pavement. Maximum shearing stress decrease, decrease, decrease and increase respectively with increase of the surface’s modulus, the surface’s thickness, base’s thickness and ratio of base’s modulus to foundation’s modulus. Meanwhile, maximum shearing stress, which is caused by thermal stress, increase and decrease respectively with increase of surface’s modulus and ratio of base’s modulus to foundation’s modulus.

Abstract: This paper studies the aerodynamic and heat transfer influence of tip structures for cooling turbine blade. Four blades with different tip features are discussed, and coupling aerodynamic and heat transfer method is used to accomplish the simulation. The results show that squealer tip can greatly reduce the heat transfer between tip surface and high temperature gas, and also it reduces tip leakage, to some extent. That’s because it exists obviously eddy near the tip surface. Tip injection holes can cool the tip surface effectively, and it will greatly reduce the temperature of tip surface. However, injection holes improve tip leakage slightly.

Abstract: Rolling dryer is one kind of dryer device with large output. The characteristic of rolling body has great influence on the output of dryer. In the paper, with the finite element method, the stress distribution of body, bolt hole, man hole and modes of rolling body are obtained by static stress and modal analysis and study of acting loads on rolling body. The results can help to enhance the efficiency of rolling dryer and provide corresponding theoretical supports for the design and manufacture of the machine.

Abstract: In this paper, according to the real circumstance, a control and inspection system has been designed which enables the fracture fluid discharge to orderly avoid those disadvantages such as pressure vibration, sand-back caused by the manual control. In this system, computer is the interface for man-machine conversation realizing parameters setting, PLC is used as online control equipment realizing the gather of pressure and flux parameters and control of valve state and status display, to achieve the best effect of discharging fracturing fluid. In the end, the paper gives us the actual results of measurement of split of oil well.

Abstract: In this paper we investigate the resistance of micro hollow wire at Giga-hertz range. In order to get the optimum method, deduction in resistance can be achieved using hollow wire with optimum wall thickness. In the analysis the H field phase in the non-hollow wire changes periodically versus r with a period two times optimum wall thickness. More interesting thing is that the resistance of interconnect can be optimized by using hollow wire with optimum wall thickness. The optimum wall thickness is proportional to skin depth. The phase abrupt change point of H field has important relationship with the optimum wall thickness. Theoretical analysis and calculation indicate that the cylindrical hollow wire can achieve 8% resistance deduction. Similar results for rectangular hollow wire are also got using FEA commercial software.

Abstract: In-process inventory can ensure smooth production process, while it may produce dull materials. The objective of this paper is to propose appropriate control strategies of dull materials. At first, dull materials were classified, handling methods were given based on their characteristics, and then the main reasons of dull materials were analyzed. These control strategies can help companies to reduce slack in materials.

Abstract: In view of the problem of mass concrete cracks during construction, the corresponding measures and methods are put forward. Generally speaking, the difference between the internal and external temperature and the basic difference of temperature are considered as the main factors influencing the phenomena. Under the FEM is adopted to simulate the stresses field of Inverted siphon during construction. Through analyzing the time-space variation law, it is fund that cracks easily appear. In the part of the middle line of the South-North Water Transfer Project£¬the quality of concrete surface of ¢ñsection in Jiaozuo has been improved obviously through the method of external insulation board, so it deserves to bepopularized.

Abstract: In view of the problem of concrete cracks during construction, the good effect of cracks prevention can be achieved if the timely and reasonable scheme of temperature control is selected. Under the 3-D FEM including water-pipe cooling is adopted to simulate the stresses field of Inverted siphon during construction. Through analyzing the time-space variation law, it is fund that cracks easily appear. In the part of the middle line of the South-North Water Transfer Project£¬the quality of concrete surface of III section in Jiaozuo has been improved obviously through the method of external insulation board.