Applied Mechanics and Materials Vols. 397-400

Abstract: The dynamic characteristic of automatic transmission system of tracked vehicle was thorough analyzed. The primary characteristic of torque converter was proposed by means of regression analysis of test result. The dynamic model of three-freedom planetary transmission was constituted using drive principles of planetary transmission. Thus the foundation of intelligent control and simulation system of automatic transmission of tracked vehicle was established.

Abstract: Vibration responses of railway steel bridge considering welding residual stress have been researched. Based on the reasonable heat source model matching the electrical arc welding, the welding residual stress in welding joints of steel bridge has been simulated. Meanwhile, it has been superimposing with the gravity stress and the actual measured dynamical stress of railway steel bridge. Then, acting all actions to the accurate finite element model, the vibration responses of railway steel bridge considering welding residual stress can be analyzed, and the conclusion that the residual stress has a significant contribution to the vibration dynamical stress in welding joints district of railway steel bridge has been obtained.

Abstract: In this paper, the numerical method was developed to flight dynamics characteristics of elastic wing under the action of the discrete gust. In this numerical method, the aerodynamic forces of the elastic wing were calculated by solving the unsteady Navier Stokes equations, and incorporating the grid velocity method to simulating the gust response of the typical NACA0006 airfoil to the step changes in the angle of attack of aircraft . it is shown in results that the calculated lift responses of the airfoil agree well with both the exact theoretical value and calculated value in reference. the elastic effect was considered with RayleighRitz method, so that the fluid dynamic,structural dynamic and flight dynamic problems can be coupled to solve. and AGARD445.6 elastic wing for the numerical simulation of the flight characteristics.

Abstract: The balance performance of the tool handle influences the machining quality. Using the tool of the sensitivity analysis, the feasibility analysis and the optimization design in Pro/e software, by reasonably selecting the dimensional parameters of the balance structure, the distance between the center of mass and the rotation axis can be zero in order to achieve the static balance. After the dynamic simulation, the dynamic performance states that the static balance model is not fully dynamic balanced.

Abstract: The power system structure of a hybrid electric vehicle (HEV) critically affects the performance of the vehicle. This study presents a power-integrated transmission mechanism that can provide six basic operating modes that can be further classified into 15 sub-modes. Switching clutch conditions helps transmission achieve speed and torque coupling. The proposed mechanism has CVT capability and an extended range capacity, and it is applicable to front-wheel-drive, rear-wheel-drive, or four-wheel-drive HEVs. A performance simulation on power and economy via Matlab and Cruise software demonstrates that the performance of the proposed transmission mechanism meets the target. Therefore, the mechanism is a feasible candidate for use in HEVs.

Abstract: Tubular evaporator is one of the key components of central air-conditioning. It is necessary to do aging treatment to relief residual stress and prevent leak phenomenon from structural deformation. Vibratory stress relief (VSR) can relieve residual stress in metal component. It has high efficiency with energy-saving, no exhausting and low cost. However vibration parameter impacts effect considerably. The author determines vibration parameter based on vibration mode and stress distribution. The relative parameters cover excitation frequency and point, support point etc. We measured residual stress both for after welding and VSR treatment lasting 30 minutes of the component. Result shows that residual stress is reduced by 61%. Residual stress between different points is decreased by 85.56% after VSR. Therefore, VSR should be carried out by vibration parameter based on vibration mode and stress distribution. At last we can say that our innovation is adapt to determine the VSR technical parameter for all metal components.

Abstract: A mathematical model of hydropower units shaft is established to characterize the rotor motion with coupling faults which compose of mass eccentricity fault, parallel misalignment fault and angle misalignment fault, and then the simulation results is employed to analyze the impact weight of faults above for vibration and rubbing based on orthogonal test. The research showed that: the major-minor order of impact factors are mass eccentricity, parallel misalignment and angle misalignment. Additionally, the rotating rate is also related to the rotor vibration, and the high rate is easy to induce the rubbing under coupling faults.

Abstract: To evaluate the stability of a van in cross-wind., dynamical model was built to deduce lateral acceleration and critical wind speed before rollover based on the theory of system dynamics and aerodynamics. Applying the simulation software TruckSim, parametric models considering the affect of aerodynamics and cross-wind model were constructed. By changing the parameters such as the wind speed the speed of van and centroid height, the influence of crosswind on roll stability of van was simulated and analyzed. More intuitive basis for safe driving in cross-wind is provided.

Abstract: Cutting arm was the key assembly of the roadheader. Since complex force condition, violent and irregular vibration, the parts of the cutting arm assembly acted with each other, which led to the surfaces wear and damage of the parts. The finite element software ANSYS was used to calculate the vibration modes of the six parts and the assembly of the cutting arm. The maximum amplitudes whose maximum order was five were got by modal analysis. According to the calculation result, it was found that the vibration frequency of internal expansion tube and external expansion tube was close in each order and analyzed the reason for their serious wear.

Abstract: A constant tension control device of mechanical feedback is designed for the tension adjustment between the unwinding and rewinding of the flexible material, and the structure and size of the device are given. According to torque balance principle and based on purely mechanical structure, this device can control tension by adjusting the frictional force between the brake block and the unwinding wheel. The tension of controlling the unwinding and rewinding of the flexible material is analyzed, and then the control method of the tension is illustrated. Compared with the common closed loop control devices with tension feedback, the structure of the proposed device is simpler, and it has a stronger capacity of resisting disturbance in complicated electromagnetic environment.