Applied Mechanics and Materials Vols. 246-247

Abstract: The paper analyzes the rotor imbalance of cooling fan for the engine, and come to influence coefficient per unit quality. Fan imbalance in the rotor will cause severe vibration of the fan and its supporting equipment. We can easy count the practice balancer cooling fan rotor. This method is very simple.

Abstract: To reveal the potential and means of energy saving and emission reduction for the parallel pneumatic hybrid vehicle (PHV) proposed in this article, the comparison analysis between parallel PHV and conventional diesel vehicle (CDV) was made on the dive cycles of NEDC, UDDS, HWFET and JAPAN10-15 using the mathematic model. The results show: For the drive cycles of NEDC, UDDS, HWFET and JAPAN10-15, the PHV could decrease emissions by 58.84%, 38.76%, 14.54%, and 66.59% and save energy by 13.12%, 14.06%, -6.27% and 28.06% respectively com-pared to the CDV; Of the five hybrid means of shutting down the ICE at idle, regenerative braking, optimizing working area of ICE, using the exhaust heat of ICE and downsizing ICE, using the ex-haust heat of ICE along with shutting down the ICE at idle have the most impact on energy saving, and then is the downsizing ICE, but using exhaust heat would increase energy consumption; Opti-mizing working area of ICE and shutting down the ICE at idle have the greatest contribution to re-duction emissions, followed is also downsizing ICE. The efficiency of regenerative braking is very low, as well as the heat exchange efficiency of the adopted heat exchanger, requiring further opti-mization and design.

Abstract: Vehicle transmission shaft assembly is an important component of automotive transmission, parts of which are facing the problem of prematurely resulting in fatigue failure. This paper responding for needs in this area, puts forward a method to predict fatigue life of vehicle transmission shaft assembly without intermediate support, based on workbench finite element software and fatigue software modules. With this method, we found the fatigue failure parts of the transmission shaft accurately and the specific location of the failure zone on the parts, which provide the technical basis for the further optimization of parts. And then contrast analysis of results with the actual fatigue fracture, it shows that the method is effective.

Abstract: Fretting damage generates under the breeze vibration condition. Fretting wear under various pitch diameter ratio at the ACSR strand interface has been studied by FEM method with the LGJ-25/4 ACSR taken as an example. The contact mechanics parameter distribution laws at the strand interface have been obtained. It shows that the peak of von Mises stress, contact pressure, contact state and shear stress at the contact spot decrease as the pitch diameter ratio increases. And the width of yield area also decreases as the pitch diameter ratio increases.

Abstract: The proportional modification parameters are useful for modifying the tooth form errors of spiral bevel gears. Based on the mathematical model for calculating the machine setting parameters and according to the relative position relationship between cutter and workpiece and the curvature and vector of calculation point, the formulae for calculating the first-order proportional modification parameters for gears machined by spread blade method was deduced. The proportional modification parameters can make the pressure angle or spiral angle of the concave flank and the convex flank produce uniform change and difference change. The formulae is verified by experiment on CNC spiral bevel gear grinding machine and M&M sigma 7 gear measuring center.

Abstract: Fatigue damage of airframe often caused by riveting defects, which resulting in failure of aircraft structure in service. Based on the theory of classical fatigue fracture, the effects of Interference-fit gap on capabilities of safe service are examined and a new method of measuring the dimension of Interference-fit gap under the different conditions is introduced by cutting test and fatigue test of typical aluminum alloy 2024-T3 in aero industries. And the admissible value of Interference-fit gap for riveting is given, which offered the technological basis to achieve long fatigue of the aircraft.

Abstract: The fuel flow characteristics in diesel nozzle orifice are key factors to the atomization of fuel near the nozzle orifice. In the paper, two-phase flow model is used to simulate the complex flow features in nozzle orifice, and to study the influences of the relative position of nozzles orifice axis and nozzle axis, and inclination angle of nozzle hole on the internal flow feature.

Abstract: In this paper, non-uniform dynamic analysis of a cable-stayed bridge is carried out using the large mass method. The Ed Yangtze River highway bridge, constructed in Hubei province, is chosen as a numerical example. In the non-uniform dynamic analysis, various wave velocities are used for the travelling ground motion. Displacements and internal forces solutions obtained for the spatially varying ground motions are compared with those of the uniform excitation. It is observed that the velocity of the ground motion greatly influences the response of the bridge and the variability of the ground motions should be included in the time-history analysis of cable-stayed bridges.

Abstract: An adaptive genetic algorithm was proposed to optimization bound in order to speed up the convergence of Gaussian mean shift. In practical question, as it's difficult to give a critical value definitely. According to the engine nonlinear of the corresponding oil and performance parameters, in gradient genetic algorithm, BP algorithm of local search is introduced. The adaptive value of chromosomes group gets quickly improved with the search in one coding field getting avoided due to the utilization of knowledge of chromosomes in problem-domain. The crossover and mutation operations are added so that chromosomes will not fall into the local minimum point in neighborhood. The experimental results prove that the convergence speed of the proposed method is non-linear and the use of gradient genetic algorithm is a fast algorithm that can support the global optimization of chromosomes in a group of process of iteration.

Abstract: On the basis of parallelogram linkage, this paper introduced the working principles of a kind of new transmission mechanism:crank-group driving mechanism, its three basic configurations and their advantages and dis-advantages.