Applied Mechanics and Materials Vols. 490-491

Abstract: The principle of the magnetic levitation cylindrical linear motion guide and the theory of vibration analysis were introduced. By finite element analysis software ANSYS, modal analysis for guide was made to get the natural frequencies and vibration modes, the harmonic response analysis was also made to get the displacement response by the cutting force on the basis of modal analysis, and the influence of displacement on electromagnetic force was analysised.

Abstract: Linear rolling guides are widely used in the NC machine tool, and usually the NC machine tool's characteristics shall been influenced by the characteristics of the guide greatly. The HSR series of liner rolling guides are taken as the research object of the paper. The methods of constructing the dynamic finite element analysis models are studied. The contact element is applied to simulate the characteristics of junction surfaces during the static characteristic analysis. The spring damping element is applied during the dynamic characteristic analysis. The static stiffness, natural frequencies, modal shapes and other characteristics are obtained by finite element analysis. Then the experiments of linear rolling guide are carried out and verified the model that had been built and calculation results of finite element analysis.

Abstract: An idea is proposed to use the controllable local degree of freedom to reduce vibration of the flexible manipulator performing the periodic task. The controllable local degree of freedom is incorporated into the flexible manipulator and used as an effective way to alleviate vibration through dynamic coupling. The feature of the periodic motion is utilized and a simple method is suggested to control vibration by constructing the appropriate modal control force via the controllable local degree of freedom, thereby counteracting the effects of the periodic exciting force. The numerical and experimental results preliminarily prove its effectiveness and feasibility in practical applications.

Abstract: The experiment shows that the Magnetic Barkhausen Noise (MBN) signal strongly depends on the elastic deformation, heat treatment state of surface and microstructure of the material, etc. Using the MBN technology that rely on the material characteristics, MBN can be used for testing the surface hardness of 60kg/m U74 seamless rail made by China Harbin welded rail plant. And the testing result obtained by the MBN method is consistent with the results obtained by the Brinell hardness (HB) method. Consequently, this non-destructive testing technique will have a strong life and an extensive market.

Abstract: In this paper, based on the experiments of high speed dry cutting nickel alloyed ductile iron with different nickel contents by graded ceramic tool, the cutting performance and wear mechanisms of graded ceramic tool were investigated. Results reveal that with the increase of cutting speed and nickel content the wear of graded ceramic tool is increased, wear mechanisms are transformated spalling and cohesive wear from abrasive wear, and chip shapes are turned into long arc segment from short segment.

Abstract: Hot cutting is strictly forbidden in coal mines, especially for those with high density of gas. As the only one cold cutting technology, abrasive suspension jet could be used in coal mines to solve the problem of cutting operation under hazardous environments. Based on the technology of abrasive suspension jet, this paper developed a portable cutting machine which is suitable for the dangerous and complex environment in coal mines. Experimental results indicate that the cutting machine could well meet the requirements of cutting operations in coal mines, such as machinery maintenance. Methods for monitoring the quantity of abrasive within the high-pressure tank and the wear of nozzle were also investigated. Safe cutting could be ensured by application of this portable cutting machine. Promotion of the technology would have significant social and economic benefits.

Abstract: Proportional navigation guidance law is widely applied in the terminal guidance of the reentry vehicle. However, the guidance accuracy of the traditional PNG law is largely affected by the wind disturbance. To improve the impact precision, the proposed method applies a feedback of angular velocity deviation to the traditional PNG law. With the proposed method, the vehicle could satisfy the terminal constraints under large wind disturbance. Also, simulation results validate that the proposed method can well enhance the performance of the vehicle.

Abstract: The Forward kinematic and the inverse kinematic were analyzed of 3-DOF cable-driven surgical instrument in this paper. Kinematics of open chain surgical instrument was derived by the product of exponentials formula, and Paden and Kahan subproblems. Kinematic analysis of the 3-DOF cable-driven surgical instrument can be analyzed by the map relationship between the end effectors and the joint angles of the surgical instrument after removal of cables and pulleys and the map relationship between the rotor angular displacement of the motor and joint angular displacement. The analysis method can be useful for motion analysis and control for cable-driven robotic mechanisms.

Abstract: The process of large belt conveyor operation must be more accurate by using dynamic analysis. Dynamic analysis and complex, not easy to grasp, needanalysis software -- conveyor dynamic analysis. Based on the status analysis of the domestic belt conveyor dynamic, about software overview of belt conveyor dynamic analysis, the design principle and the belt conveyor dynamic, analysis and applicationof dynamic analysis software.

Abstract: Based on a 1/4 vehicle suspension testing laboratory platform for testing, analysis and study the relationship of parameters between car tire pressure ,stiffness and sprung mass. Use Matlab for data processing and numerical analysis. Establish tire pressure and tire stiffness nonlinear relationship. For the subsequent dynamic tires test and combination suspension System research to provide theoretical reference and practical basis.