Advanced Materials Research Vols. 490-495

Abstract: The simplified finite element modal was established with ANSYS aiming to study the spindle box. The changing regularity of the first 6-order natural frequency of spindle box was studied after the static and modal analysis. Shape optimization design was carried out by taking the maximum deformation of the direction of X，Y，Z as the objective function. The results show that the structure of spindle box after optimization can effectively reduce the maximum deformations of the direction of X，Y，Z，and has better static and dynamic characteristics.

Abstract: A new cooling concept for high power LED street lamp by combining the heat release of high power LED with two-phase heat transfer heat pipes was proposed, and in this study a series of heat pipes with specific fins structure were developed. Through experimental results, we found the new heat pipe heat exchangers have the features of higher efficiency of heat dissipation and more compact construction which meets the demand of heat dissipation for high power LED than the traditional heat pipe heat exchangers and the new exchanger with outwards-radiate structure has the best heat dissipation performance.

Abstract: The initial boundary value problem for parabolic equation with Neumann boundary condition is a kind of classical problem in partial differential equations. In this paper we use the artificial boundary to solve the moving boundary problem. Potential theory and difference method are discussed. Numerical results are given to support the proposed schemes and to give the compare of the two methods.

Abstract: Being established in the requirement of teaching and practice, and connecting to the development of process equipment and control engineering specialty, a suit of experiment teaching instrument is designed, which relates to process control, automation, survey and control and correlative specialties. By the instrument, students can taste the actualizing of process equipment control and the application of advanced technology when learning engineering theory. This stimulates their enthusiasm in specialty courses study and enhances their practice capability and creative thinking

Abstract: To achieve engineering application of pulse motor as soon as possible,designed a soft pulse separation device(PSD), numerical simulated its process of bearing pressure and turning on,used the XFEM to simulate its failure form,got strain and stress distribution,found the bearing capability and failure form of the structure of soft PSD was reliable;Designed a few of verification monomial tests,verified the accuracy of simulation,proved that its bearing capability and failure form satisfied with design requirements,could be applied to pulse motor.The simulation technique,test method and conclusion are useful for designing pulse solid rocket motor configuration.

Abstract: When drillstring rotates through the bending section of horizontal well, the fatigue damage of drillstring will be caused by alternating bending stress. Therefore, a thought to solve the fatigue reliability problem of drillstring in bending section of horizontal well is proposed. The variable amplitude alternating stress is transformed into equivalent fatigue stress, and the fatigue damage of drillstring is analyzed. Considering Palmgren-Miner rule and S-N curve, the fatigue life and reliability evaluation model of drillstring in bending section of horizontal well is established according to the fatigue reliability theory and probabilistic fracture mechanics. This model can calculate the fatigue damage, fatigue life and reliability of drillstring in the process of drilling and the maximum allowable dogleg angle where the drillstring is under compression and tension. And it has the important reference value for the fair use of drillstring and casing program design.

Abstract: To further increase the lift and rotate speed of a micro flapping wing rotor, a electromagnetic mechanism is designed to achieved high amplitude and small friction. Then average propulsive force using Theodorsen’s theory is simulated to confirm the parameter affect. In the end, the relationship of average lift, average propulsive force, rotate speed are shown in the experiment and test results represent that this mechanism has much better performance than PZT one.

Abstract: In this paper, a planar five-bar mechanism driven by two orthogonal layout actuators is proposed. The inverse and forward kinematics can be described in closed form. The Jacobi matrix, singularity and workspace of the mechanism are investigated. In addition, charts of some performance indices, such as dexterity, velocity, payload capability and stiffness index, are plotted. The results show that the mechanism has a flatter singularity-free workspace, which is usually our research object. On the other hand, Dexterity, Payload capability and stiffness index of the mechanism are basically the same distribution on the workspace, which are axis symmetric. But, the trend of velocity index is opposite. The proposed mechanism can be applied to the field of machine tools or used as the mobile base for a spatial manipulator. The results of the paper are very useful for the design and application of the new mechanism

Abstract: According to the characteristic of abounding use of digital information in the domain of maintenance of equipment, design a sort of PMA system which is high efficient, low dissipative and convenient to operate. The system is consisted of free scale i.MX51 embedded microprocessor, that its core is the newest ARM Cortex-A8 chip, and Windows CE operating system. Therefore, it achieved various functions, such as interactive query of IETM, sampling video and audio information, analysis fault, downloading and examining the maintained tasks and records

Abstract: Based on the theory and semi-empirical formulas, the surface heating flux of hypersonic flying vehicle under aerodynamic heating is calculated by using reference enthalpy method. On this basis, the thermal response of structure made of ultrahigh temperature ceramics(UHTCs) is simulated by using finite-element method. The results show that thermal stress shock is able to cause material to damage in a very short time