Applied Mechanics and Materials Vols. 602-605

Abstract: Micro cutting is a promising way for manufacturing micro parts, especially micro three dimension parts. Micro hardness is an important character to evaluate surface integrity of machined surface. Micro cutting is different from macro cutting due to size effect of specific cutting energy because of the influence of the ratio of uncut chip thickness to cutting edge radius. A group of micro cutting experiments were conducted to investigate the cutting parameters on the micro hardness of machined surface. The micro hardness of machines surface decreases with the ratio of uncut chip thickness to cutting edge radius first, and then increase when the uncut chip thickness is smaller than the cutting edge radius. The micro hardness shows size effect due to the machined surface compressed twice with the round cutting edge. The micro hardness decreases with the distance increasing far away from the machined surface.

Abstract: AutoCAD has obvious advantage on plotting AutoCAD assembling drawings at present, but the plotting speed and difficulty of assembling drawings are always two problems to puzzle most architects and draftsmen. Making use of AutoCAD drawings object property, layers and layer isolation function, a sort of fast effective drawing method is innovated, and it can solve the above problems perfectly. Practice proves that this method can be applied effectively to the plotting of mechanical assembling drawings, and it can obviously enhance plotting efficiency and reduce plotting difficulty.

Abstract: Aim to the difficult problem of the inclined hole machining, the vibration drilling method is analysed and adopted. The experiment of the 60°inclined hole drilling on high-temperature alloy was performed, and the notable effects were obtained. It can be draw from the results that the vibration drilling method break the limit of the jig for the inclined hole driling. The vibration drilling the inclined hole has became the new path.

Abstract: Based on the traditional injection molding technology, micro-injection molding of UV curing experiments has been conducted. The injection molding and repeatability of the parts which have micro-structure were mainly studied. The experimental results show that: the mold-ability and repeatability of micro-structure are significantly infected by UV radiation energy and forming temperature. In order to achieve a good repeatability, it is necessary to use a sufficiently high intensity ultraviolet radiation and appropriate molding temperature during micro-injection of UV curing.

Abstract: The vortex-induced vibration and heat transfer of circular cylinders at low Reynolds number (Re=50~180) was numerical analyzed. The cylinder motion was modeled by a mass-spring-damper system, and the motion equation of the cylinder was solved by Newmark-β method, and then the cylinder velocity was written into the UDF of Fluent, finally, the dynamic mesh technique was used to solve the coupling between the cylinder and flow. The results including “Lock-on” and “Beat” phenomena were obtained, and the effect of mass ration on "Lock-on" was analyzed, furthermore, the influence of vortex-induced vibration on convective heat transfer was also discussed.

Abstract: The maintainability of aircraft has a direct relationship with the reliability, availability, security and economy of the airplane and its components. From adopting the new composite material, innovative self-test system and the close cooperation with airlines, airports and airworthiness institutions, the airbus A380 will ensure its better maintainability. This paper intends to discuss the developing and designing direction of the civil aircrafts’ maintainability in expectation of marking some active contribution to the industry of large aircrafts in China.

Abstract: The steering system is one of the most important system on the Vehicle, whose reliable function is related to the motion safety of the vehicle. In this paper, taking a simplified model of a vehicle steering system as the researched object, modal analysis of the steering system was carried out based on the finite element software ANASYS. The analysis process can be used to optimize and improve the design of the steering system, and avoid the resonance between vehicle and the uneven road.

Abstract: This paper derives formula which computes the width of equivalent groove of the 3D complex groove of the indexable turning insert when cutting medium carbon steel uses the theory of chip curling and breaking. The formula was computed by MATLAB program. The calculation method of the width of equivalent groove is proposed. The cellular automaton model which designs the line-arc curve of groove of indexable turning insert with the 3D complex groove is established. One evolvement rule was confirmed and a program was designed to realize the dynamic evolvement and design of the groove curve. This research provides a base for the groove design and optimization.

Abstract: The principles and method of computational fluid dynamics were applied to numerical simulate the external flow field about the SUV model. The hybrid mesh of tetrahedral and triangular prismatic as well as the turbulence model of Realizable k-ε was adopted to study the flow field of SUV of flat underground. Then the SUV of complex underground was simulated with the same mesh strategy and boundary condition. The aerodynamic drag coefficient of latter was bigger than former. That illuminated the complex underground has affect to aerodynamic performance of vehicle. The wind tunnel test validated the veracity of numerical simulation. Based on that, the underground cover board was appended; the aerodynamic drag coefficient was depressed. The velocity and pressure distribution and flow line were achieved. The conclusions provide theoretical reference for the further study of aerodynamic drag reduction of complex underground.

Abstract: The current Jilin University’s energy-saving car has two problems.Firstly,long time driving let the driver get a pain in the neck,which is uncomfortable. Secondly,the low overheight of the carbody result in a bad vision. This paper try to show how we solve these problems. In order to ease the neck pain and better the vision, the driving space should be increased,which may result in the grow of aerodynamic drag.That’s not welcome. So as to realize the relative balance between driving comfort and aerodynamic drag of energy-saving car. Our group consider the relationship between these two factors, make a wooden model to get the feedback about the actual feeling and calculate the aerodynamic drag by using analysis softwares. Finally,we got a better design plan which satisfied both the aerodynamic drag and driving comfort. The new design plan not only bring energy-saving car’s driving more comfortable,but let us accumulate lots of design experience of energy-saving car.