Applied Mechanics and Materials Vols. 52-54

Abstract: The paper puts virtual prototyping technology,finite element technology and optimal design into the design of hydraulic support for the development status of hydraulic support and the problems in the traditional design. It takes ZF2800/16/24 hydraulic support as a model and establishes the 3-D model of hydraulic support by using Solidwork sofrware, also builds the simulation model of the hydraulic support and does a simulation exereise.The performance of the four link bar is analyzed.By analysing to the canopy which is subjected to torque by using Cosmos software, the paper obtains the stress and strain distribution of all the elements or nodes on the canopy by a graph. From the analysis of the result ,designers can fully and exactly find out the force of all points of the canopy .And this way can also solve the question that there is not enough number of the testpoint in the traditional prototype test. In the meantime, the canopy can be optimized because its biggest stress is far smaller than the allowable stress of the material. And the canopy can be optimized,increase the economic benefit.

Abstract: The strength and stiffness of 4300 rolling mill housing affect the quality of plate much. In presented research a problem that belongs to the stresses, deformations and modal analysis topic was investigated. The finite element method (FEM) and the electrical measuring method were used for the investigation. Modeling, meshing, loading and analysis on the housing are finished by Pro/E and Ansys 10.0. The dangerous point locates on the chamfer of upright and low carriage. The FEM results are larger than those of measuring by comparison. Natural frequencies and main vibration modes of the housing from first to fifteenth step are found. The dynamic bending and twisting deformation are the main factors which affect the dynamic characters of rolling mill. The middle of upright is the weakest position. The results of this article supply the basis for understanding the working state, maintenance and design of the 4300 rolling mill housing.

Abstract: A new mechanism construction for small tooth number difference planetary gear drive is developed in which the planet wheel is guided by a planar crank and oscillating block mechanism. The sizes of linkage are design dexterously to get an approximate circumference linkage curve so that the engaging condition of internal gear pair can be satisfied. The trajectory of the inner gear center motion is analyzed and its error comparing with a standard circle is calculated to avoid movement interference. The movement of inner gear is study particularly to deduced formula of instantaneous transmission ratio. Despite observable fluctuation of output speed, this new type of gear transmission mechanism still has potential application value in situation with large ratio and low input speed. A hand drive winch prototype using the mechanism is also illustrated in this paper.

Abstract: In recent years, study on the regularity of gas moving has been emphasized due to the more seriously problem of mine gas which caused by the ever increasing of mining depth and rate in the coal. As the important source for the workplace gas, the goaf gas always causes a exceeding of the safety limit at the upper corner, it not only influences the sustainability, stability and security of the mines, but also serves as the primary cause of the accidents. In order to discuss the migration and distributed rule of the goaf gas, this article based on computational fluid dynamics, in accordance with the seepage theory and on the premise of analysised the fluid state of goaf gas, the distribution rule of goaf gas moving has been studied by establishing a mathematical model of gas seepage and distribution in the goaf area with a given boundary condition. The research has provided theoretical basis for the analysis of gas density at the upper corner of the mines, demonstrating its theoretical and practical significance in preventing gas overrun and safeguarding safety in coal mining.

Abstract: To study the micro-structure of collapsibility loess, the triaxial shear test under pressure of 10MPa to 100MPa and consolidation test under 1000kPa, 2000kPa and 4000kPa were respectively used on collapsibility loess here to imitate the working condition of dynamic compaction. Micro-images of the soil samples in above tests and undisturbed soil samples were collected by SEM at 500 enlarge. The results of images analysis are that the flocculated structure is destroyed drastically under compaction; the macrovoids and large set of grains are destroyed and recombined with tamping energy’s increase and the primary unordered sank is recombined and more dense and directional.

Abstract: Dynamic analysis is conducted for a cracked beam with imperfectly bonded piezoelectric patches using the finite element method in the paper. The property of adhesive between the PZT patches and the host beam is taken into account based on the peel stress model as well as the shear lag model and thus the three-dimensional (3D) model of piezoelectric patch-adhesive-host beam coupled system is developed. Based on the established three-dimensional EMI model, the effect of some physical parameters such as vibration mode of main structure, the mass of adhesive layer and crack depth etc. on electromechanical impedance signatures is investigated. Finally, the root-mean-square deviation (RMSD), a kind of non-parametric damage index, is also employed to identify the damage severity of the cracked beam.

Abstract: Fractal theory has been established for more than 20 years. Taking the fractal theory into solving geotechnical engineering problems has been gradually perfected. This paper concludes several common methods within the fractal theory research. Meanwhile, sums up the research results of the predecessors during the correlation field. At last, illustrates the application of fractal theory within the geotechnical engineering problems' research in detail, such as the microstructure fractal of soil, the fractal dimension on the joint surface, the relation between fractal dimension and rock quality coefficient(RQD), fractal damage and fractal fracture, and application of fractal theory(mechanics) to related geotechnical engineering.

Abstract: The polycrystalline diamond compact (PDC) is the key component of the diamond bit used in oil drilling. PDC is manufactured by die-cast molding process. The PDC die withstand 1500 degree and 6000 MPa, the designing process is very complex, it is necessary to develop a CAD software for PDC Die, it can improve design efficiency and accuracy. The software has been developed and used in Kingdream Corp. of China for many years.

Abstract: As some prevalent wired networks in industrial field are based on TCP, we proposed a novel integration infrastructure of token-based industrial WSN protocol and TCP, so as to make the application of wireless communication technologies more flexible. In the paper, a protocol conversion infrastructure is presented, which is based on data mapping mechanism. The protocol converter includes two modules: Wireless Industrial Control Network(WICN) master module and TCP host module. WICN master module owns an exclusive data buffer called WICN data buffer. TCP host module also has its own data buffer which is named TCP data buffer. A public data area is used for realizing the data mapping between WICN data buffer and TCP data buffer. By the data mapping mechanism, a station in wired network segment could get the data from WICN by accessing TCP data buffer, and WICN slave station could get the data from wired network via WICN data buffer. By the protocol conversion mechanism based on data mapping, flexible data exchange of heterogeneous networks could be realized.

Abstract: Because consider aerodynamics and make its modelling tends to streamline in the car design, this article mainly describes streamline design for product create better use of convenience for the product brings outside the modelling and mental and emotional intangible value, this also is industrial design create products value-added effective means recently, Ultimately this article give some suggestions to designers to put forward some reasonable use of streamline design.