Applied Mechanics and Materials Vols. 444-445

Abstract: Application of super elasticity theory and nonlinear theory, based on finite element method and the Abaqus software, the performance of Y ring rubber seal, such as the Von Mises stress, the sealing ring deformation and the contact pressure were simulated and analyzed under the influence of changeable hydraulic pressure. According to seal failure criterion, the effect of hydraulic pressure changes on the sealing performance were studied. Results show that, the maximum stress appears in the intersection of lips, the largest deformation area near the inner lip. The root has greater contact pressure, which would result in bitten phenomenon or aggravate wear.

Abstract: The article describes how we can use the virtual prototyping technology validate mechanism design of multi-joint manipulator and its grabbing performance and loading abilities per minute. It completes the three-dimensional model of virtual prototype with Solid Edge ST5, and be imported into ADAMS software. And then the manipulator kinematics simulation is carried out in ADAMS. Using the kinematics simulation technology of ADAMS, we can get the various joints in a working cycle of the displacement characteristic curve, the velocity and acceleration curves of working conditions. This paper introduces how to establish the geometric model of articulated robot virtual prototype model. And some key technology details such as adding a constraint to model are also described. Kinematics simulation analysis of the manipulator with ADAMS software can greatly shorten the design cycle, improve design accuracy and reduce the cost of product development.

Abstract: In this paper, the distribution network structures divided as per the possible state configuration sequences based on different switch states (close/open) are analyzed with FMEA algorithm and calculated with regional equivalent improvement method. All switch configuration solutions will be assessed after the different regional economic advantages are fully considered and then the highest power availability solution on average is found. The case research shows that when the switch configuration comes to 111001, we get relatively balanced powersupply load of every branch and relatively high standard indexes.

Abstract: This paper presents a pointer positioning method based on Hough transform, which turns an arc scale to a transverse rectangular scales, scans the region from bottom to top line by line, determines smaller rectangular area containing pointer only, uses Hough transform in linear theory to detect the pointer position in the region. Experiments show that this method can locate the pointer position quickly and efficiently in analog measuring instruments.

Abstract: The severe aerodynamic heating on the surface of modern hypersonic flight vehicle, that can bring high temperature and large temperature gradients in the structure of the vehicle, will be a challenge for the vehicles design and multidisciplinary optimization. The transient thermal environment consists of high temperature and large temperature gradients will generate two important problems related to vehicle structure, namely: 1) the material property, such as elastic modulus, will be degraded at elevated temperature, and 2) the non-uniform thermal stress cased by large temperature gradients will change the stiffness distribution of wing structure, which can make the modal frequencies and shapes of structure changed remarkably. Firstly, the theory and methodology of structure modal analysis in transient thermal environment is outlined. Subsequently, the transient temperature field of structure considering aerodynamic heating is obtained by employing computational technology of aerodynamic heating/structure heat transfer coupling program. Finally, the modal frequencies and shapes of vehicle structure under transient temperature field is calculated based on finite element method (FEM). Based on the analysis and investigation of the simulation results, the influence of the transient thermal environment on structure modal frequency and shape is determined. Furthermore, the investigation of wing structure modal analysis considering aerodynamic heating is an important basis of aerothermoelastic simulation.

Abstract: Beginning with an introduction of algorithm principle for Baseband Equipment to implement carrier acquisition in digital field, costas loop of acquisition and tracking, PSD estimation of FFT frequency guide are developed. Then the quality of classical PSD estimation and Modern PSD estimation has been analyzed and compared especially by Matlab simulation.

Abstract: The temperature distribution has important influence on the position and shape of solid-liquid interface during directional solidification process. So the calculation of temperature field is fairly significant for both structural analysis and temperature control. In this paper, the finite element method is applied to establish the 2D axisymmetric model for modeling the temperature distribution and the solid-liquid interface shape of multicrystalline silicon in semi-industrial directional solidification furnace. The numerical results show that the temperature field and solid-liquid interface shape can be controlled by adjusting the pulling rate in directional solidification process, and an optimized pulling rate of this system was obtained for large diameter silicon crystals with low defect density and uniform dopant distribution.

Abstract: In this paper, an algorithm is presented, which takes grid clique as a whole to find its all instance points neighbor lists in 9-neighbor area, and inserts them into the candidate extension clique list, then deletes the records that dont meet the criteria in the list, finally combines grid cliques and candidate extension clique list to generate maximal clique. The paper discusses the characteristics of spatial co-location pattern algorithm, and makes statistics of its maximal clique number generated in different distance threshold. The experiment shows that the improved algorithm can find out more maximal cliques.

Abstract: Based on the theory of the thermal conduction and the thermal elastic equations, does some researches in view of the thermal Damage of K9 glass by finite element analysis. The distribution of temperature field and thermal stress field of the ideal K9 glass which irradiated by 100W pulsed-Nd: YAG laser are simulated with finite element software. The result shows that the temperature of the surface of glass doesnt reach the melting and the thermal stress of it doesnt get to the requirement for fracture strength. Then, the model of K9 glass containing inclusions has be built. The simulation result indicates that inclusions may affect the distribution of temperature field and thermal stress field of the K9 glass, which makes the injected laser beams energy centralize on a small area around the inclusions owing to the existence of the strong absorbing, thus leading to K9 glass laser damage threshold reduction and easier to thermal damage.

Abstract: Considering that food always be spoiled in an oven, an analysis of the heat distribution of an object (pan) in a thermal insulation space has been done. The analysis based on the characteristics of heat transmission in an oven. A mathematical model is designed to illustrate the heating process. Specifically, in order to monitor the temperature of the object, pdetool in MATLAB is used to solve the heat transfer equation. Then to evaluate how an object performs in the oven, a method of standard deviation has been introduced. For the efficiency, valid heating area should also be considered. Thus an evaluation is made to choose a most preferring pan, which is balanced between heat distribution and valid heating area (number of pans). The experiment shows that shapes would devote much in performance. It is also demonstrated that there is a certain shape that can be most suitable to be a pan.