Applied Mechanics and Materials Vols. 341-342

Abstract: Electric vehicles will longitudinally vibrate obviously under acceleration and regenerative braking conditions (because of torsional vibration of the electric vehicle powertrain). This paper includes models of motor rotor, gear reducer and differential assembly, half shafts, tire and body and nonlinear powertrain dynamic model in consideration of gear backlash and frictional characteristics between tire and ground. Real car tests confirm that it is correct under acceleration conditions. Then a two mass-spring damper linear model which is simplified from the nonlinear powertrain dynamic model is proposed to design torsional vibration control algorithm based on state feedback. The simulation results show that the algorithm can actively eliminate torsional vibration.

Abstract: A simulation model of a certain wheel loader is established to assess the restraint effectiveness of seat belts in 90° rollover accident along slope. The restraint effectiveness of seat belts for 95^th percentile human body models are simulated which wearing lap belt, three-point belt and harness at a certain speed, and the influences of initial velocity and ground stiffness are analyzed. The results show that under a certain forward speed and same ground stiffness, wearing the harness can make the operator completely restrained in the operators seat comparing with the other belts, the head excursion is smallest, and it can reduce the risk of the head striking hazardous features of the cab interior. Under the same restraint system, the dummy's injury risk is inconsistent with change of initial speed. The harness can all provide the best restraint for the operator under different forward speeds and ground stiffness.

Abstract: The parameters matching of the hybrid powertrain system of the hybrid electric vehicle has a directly impact on the performance of the vehicle dynamic and the fuel economy. The preliminary match of the powertrain system base on analysis of Driving Cycle is done, then the software of AVL-Cruise and Matlab are integrated with Isight to optimize parameters of match, by using the Multi-Island GA and NLPQL to establish the combinatorial optimization algorithm. The results show that the fuel economy have been improved by 10.92% without sacrificing the dynamic performance and under the premise of ensuring the limits of the state of charge of battery.

Abstract: For cutting down the stress and displacement of banded wedge and synchronous V belt drive in the transmission process, promoting the transmission mechanism, and improving quality of the belt drive, the working principle of the transmission mechanism was introduced briefly. The three dimensional solid model of the transmission mechanism constituted in pro/e; the main parameters of the model were set using ANSYS Workbench. And then the serialization simulation analysis of the transmission mechanism was achieved when the tension force is located in the point of the V belt exiting meshing with the driven wheel; the cloud diagram of Von Mises stress and the maximal Von Mises stress and total deformation of the transmission mechanism were elicited. The simulation results were analyzed. The simulation results show that the maximal equivalent stress and maximal total deformation of the transmission mechanism are determined by the size of the tensioning force when the active force is small. Augmenting the active force of the transmission mechanism the maximal equivalent stress increases effectively and the maximal total deformation changes little when the active force is large. Reducing becomingly the tensioning force in ensuring natural belt drive shall reduce effectively the maximal Von Mises stress of the transmission mechanism. Adjusting opportunely the location of the tensioning force the total deformation of the transmission mechanism reduces effectively.

Abstract: Turnover mechanism is one of the important parts of the element bar conveying subsystem in the aluminum electrolytic capacitor assembling machine (AECAM). This paper analyzed the structure and motion characteristics of the turnover mechanism, and used the ADAMS software to do its parametric modeling, dynamic analysis and optimization design. Finally the paper concluded that Final result of turnover mechanism optimization was that the maximum of resultant force in the cam rotary center decreased by 49.3%.Application of ADAMS software will provide a new way for design and improvement of the assembling machine in future.

Abstract: The main content of gear design is the strength design, and the contact strength design of gears is the main heart of the strength design, because the stress and deformation of gears directly affect their safety and service life and concern whether vehicle transmissions work smoothly. Therefore it is necessary to perform a finite element analysis for the gear contact in transmission. Based on the contact characteristic of helical gears, a three-dimensional solid model was established by using the software Pro/E, and the contact stress analysis of gears was carried out by the software ANSYS Workbench. The stress and strain distribution contours of helical gears were obtained, and then the check of shtrength and rigidity was performed. Thus, it is convenient for designers both to test the strength of gears and to modify the size of gears.

Abstract: According to the traditional methods to design the gears in gearbox, the effect of the volume or noise of gears can not be involved. In order to design better gears, this paper used the simple and effective weighting method and considered the three aspects of minimizing the sum of volume of gears, the bending stress in tooth roots and the working noise to design gears. A mathematical model of optimal design of gears was established, where the contact fatigue strength on tooth surface, bending fatigue strength in tooth roots, tooth number, helix angle, big end modulus, overlap contact ratio, tooth width and so on were set as the constraint conditions and the big end modulus, the tooth width, helix angle of tooth width midpoint, and tooth number of the small bevel gear when transmission ratio is given were chosen as the design variables. Finally an example was solved. The results show that the present method can scheme out the gears of lower noise level.

Abstract: Asphalt paver usually produces pressure shock in the starting process, makes the velocity fluctuations increase, have great influence on pavement quality. This paper carried out the analysis of the causes of asphalt paver started the process of starting pressure, through simulation software to analyze the influence of different starting time of starting pressure driving system in commonly paving speed, puts forward the measures to reduce the hydraulic impact.

Abstract: The seeder of rice bud-seed for field seedling raising is a new seedling equipment for field seedling raising, which is a complicated vibration system with multi-freedom. And the effect of the vibration parameters and interactions on the vibration velocity at different locations of the moving rail of two electromagnetic vibration metering devices which are installed side by side is large, and the passing rate of seeding is affected. In this paper, the virtual prototype of seeder of rice bud-seed for field seedling raising is established by ANSYS and ADAMS. The virtual prototype is developed to carry out dynamics simulation by using four-factor quadratic regression orthogonal rotary combination design. Mathematical models of influencing factors of vibration and variation coefficient of vibration velocity, and the factors and average velocity of seeding are established. The factors are optimized. And optimal combination of vibration influencing factors and the variation coefficient of vibration velocity interval with 95% reliability are achieved. The result shows that optimal combination of factors is achieved under the condition that the excitation force amplitude is 39.8N, vibration frequency is 32.7Hz, the velocity is 58.5mm/s, stiffness of vibration isolating rubber pad is 1167N/mm. The corresponding variation coefficient of the vibration velocity is 6.287%, and the average seeding velocity is 18mm/s. The variation coefficient of the vibration velocity interval with 95% reliability is from 2.909% to 9.665%.

Abstract: A preload adjustable new ultrasonic vibration extrusion system was designed based on one-dimensional theory of elastic, moreover, the vibrator also has passed simulation analysis tested by Ansys. The influence of the flange structure to the resonance vibration mode of the vibrator was proposed. Finally its vibration performance was verified by impedance characteristic test and conformed to the processing requirement.