Applied Mechanics and Materials Vols. 496-500

Abstract: In this paper, the modal of motorcycle frame is analyzed by using the analytic method and experimental method. The results show that the dynamic properties of the finite element model are in good agreement with the experiment and the finite element model was reliable and accurate.

Abstract: Pico hydro turbine is an alternative technology for electricity generating from small hydropower. It is suitable for use in a rural area because of the constructions are cheap and the techonogies involved are conventional. This research paper presents the designing and the testing results of the electricity generating from the pico crossflow turbine, for save in a battery 12 V. A testing of pico crossflow turbine with 0.8 m diameter of wheel and a 20 blades water turbine which has a semi-circle shape at 0.1 m diameter of blade, the length of the blade is 0.8 m, tested in river, showed that the system gives the best electrical power of 145.42 watts or 3.49 kW-hr per day, enough to supply for up to 6 families of small community in the rural area and the rate of return for electricity generating at 0.023 USD per kW-hr.

Abstract: Dynamic behavior of a semi-infinite elastic beam to a moving single sinusoidal pulse was theoretical investigated. An analytical model was developed based on the Bernoulli-Euler beam theory. The solutions of the deflection and stress of beam were obtained by using the superposition principle and applying the techniques of Fourier transform. It is found that when the moving pulse reaches a critical velocity for a given moving pulse duration, the maximal absolute value of stress in beam attains its maximum value.

Abstract: Based on the geological and the experimental data of the 13# coal seam of Sun-Cun Coal Mine, the relationship curve between the geothermal heat in Sun-Cun coal mine and experimental wind speed has been fit out. According this and the laboratory experiments, the relational expression between the period of spontaneous combustion in coal sample and the wind speed has been developed. The research results show that the curve of wind speed and the spontaneous combustion period fitted quadratic polynomial forms.

Abstract: A method of suspension optimum design based on the tire and vehicle matching was introduced in this paper. Firstly, the vehicle handling stability evaluation standards considering tire matching with vehicle were determined by the subjective and objective assessment. Secondly, the quality, suspension kinematics and compliance characteristics and tire mechanics of prototype were tested. The vehicle model of prototype was built in Carsim with the corresponding experiment data. The model was verified by the results of the vehicle handling stability tests. Then a combination simulation platform was developed by making use of Isight, Matlab and Casim. Finally the optimal design of suspension kinematics and compliance characteristics and tire mechanics were conducted, taking straight running performance index, high-speed driving safety index and high-speed cornering performance index as the objective. The simulation results indicated that after optimization, the straight running performance and high-speed cornering performance of prototype could be improved.

Abstract: In the design of structure of oil perforating gun, for on the depth of perforating gun blind hole diameter, and the gun body wall thickness design is the key technology, through the introduction of optimization design technology, under the condition of satisfy the use requirement, language APDL of ANSYS software parametric optimal design of several data, the minimum wall thickness can get a gun. And on this basis, the blind hole diameter and depth was studied the influence of the strength of perforating gun. Conclusion shows that with the increase of blind hole depth, blind hole gun gun with blind hole part of the equivalent stress increased significantly, the strength of the blind hole depth of perforating gun has a great influence, and the intensity of blind hole diameter has little effect.

Abstract: Turn coil clamp is an important auxiliary equipment of steel rolling production in iron and steel enterprise. At present, although the clamp has been put into production use which can satisfy the basic needs of enterprise. Its production efficiency and security still need to be improved. Based on the above case, this time a new steel coil clamp that is researched can greatly improve efficiency and safety. To make the structure more reasonable, the double shaft which is one of the main stress components is needed analysis and optimal design.

Abstract: Transient electromagnetic transmitter is a part of the transient electromagnetic detection system. In the aspect of short turn-off time for high-power current, there are still many problems to be solved urgently. This paper put forward a design scheme of transient electromagnetic transmitter, amplified the control signal with triode, and put forward a kind of passive constant voltage clamping absorbing circuit, which made the turn-off time shorter and the linearity of the emission currents lagging edge higher. This transient electromagnetic transmitter system is portable and easy to operate. Through experiments we can prove that the transmitter has the characteristic of short turn-off time and high reliability, and it has reached the requirements of field application.

Abstract: The pitting fatigue failure is one of the main gear failure modes, and it has extremely important significance in studying on the influence of dynamic characteristics on pitting fatigue failure. The article has set up increasing-speed test-bed, using photoelectric encoder and NI DAS to measure and collect rotational-speed pulse of driving wheel and driven wheel. Arc-length difference and rotational-speed difference of driving wheel and driven wheel are analyzed to verify gear rattling phenomenon under increasing-speed transmission. And then gear surfaces under certain cycles are observed and analyzed utilizing surface mapping microscope to explore the influence of gear rattling on pitting fatigue failure under increasing-speed transmission. It is shown that there is rotational-speed difference between driving wheel and driven wheel, which indicates that gear rattling phenomenon appears in the meshing process, or more precisely, gear rattling phenomenon appears on both surfaces of the tooth because rotational-speed difference fluctuates bilaterally. In addition, tooth surface contact stress is 221.3Mpa, in theory, if actual contact stress is less than fatigue limit, pitting fatigue failure should not occur. However, through gear surface observation, pitting phenomenon authentically appears with the tendency from micro pitting to destructive pitting. In a word, gear pitting fatigue failure is induced by gear rattling to a certain extent.

Abstract: In view of power system in water-air UAV requirements, combine with the centrifugal impeller for aero-engine and the pump impeller. The design of a impeller of centrifugal compressor can work on the air and in the water for the new concept of air-water engine. With 3D design and a 3D CFD solver on it and analysis the results of numerical simulation. Results show that the designed impeller successfully reached the goal on the air and in the water. The experiences accumulated in this procedure are useful for similar impeller aerodynamic designs.