Applied Mechanics and Materials Vols. 644-650

Abstract: Soil constitutive model was established based on elastic model and Mohr-Coulomb model. Simplified common form track shoe was determined for finite element modeling. Loading and boundary conditions were determined based on the actual driving conditions of the vehicle. Meshing was based tetrahedron. Finite element model was compared with experiment to verify the validity.

Abstract: The unbalanced magnetic pull (UMP) of hydro turbine generating sets (HTGS) is one of the main reason induced vibration of the HTGS and the power plant. To study the effects of UMP on the shaft vibration characteristics of HTGS, this article constructs whole HTGS system which include hydraulic turbine and its hydraulic system, generator, transient model of the HTGS shafting, excitation and governing system, to simulate the actual operation of HTGS. The shafting vibration is simulated under different characteristics of UMP, simulation shows that the frequency resonance zone of the UMP has large influence on the shafting vibration. And then, the improved Prony algorithm is applied to extract the shafting oscillation characteristics of HTGS, and is effective. It provides a good method to research the effect of frequency and amplitude changes of UMP on the shafting vibration.

Abstract: Mechanical suspension test rig is much cheaper, but is can not meet the requirements of the suspension in-depth study. The reason is that the frequency and amplitude of the bench is immutable. According to the requirements of practical use, the frequency and amplitude control equipment is designed to arbitrarily change the vibration frequencies of the left and right wheels,and it can change the vibration amplitude of the wheels with a range of 5~12mm. It can meet the suspension test requirements.

Abstract: For the purpose of researching the top-hung mechanism for open and close and the improvement and use of the mechanism, improving the work efficiency, the three-dimensional solid model of the mechanism was established with ADAMS. Each part of the model in ADAMS was set up. Simulation analysis on the working process of the mechanism was achieved. The structure optimization parameters of the mechanism were obtained. The result proves that when the vertical location of the upper endpoint of lid was increased the total support reaction force acting on the lower endpoint of lower rocker by frame reduced. When the horizontal location of revolute joint of lower rocker and frame, the horizontal location of revolute joint of lower rocker and lid were increased the total support reaction forces acting on the lower endpoint of lower rocker by frame added. The sensitivities of the total support reaction forces acting on the lower endpoint of lower rocker by frame on the initial values of the locations of revolute joint of lower rocker and link, the horizontal location of revolute joint of lower rocker and frame are greater. The sensitivities of the total support reaction forces acting on the lower endpoint of lower rocker by frame on the initial values of the vertical location of revolute joint of upper rocker and link, the horizontal location of revolute joint of the lower rocker and lid are smaller. The sensitivity of the total support reaction force acting on the lower endpoint of lower rocker by frame on the initial value of the vertical location of the upper endpoint of lid are least.

Abstract: This paper researches and analyzes the modeling of electro-hydraulic proportional servo system to improve the characteristics of forging hydraulic servo control system and meet their requirements of forging a variety of materials. Based on robust compensator design, PID control strategy is proposed with uncertain disturbance of hydraulic press hydraulic servo system and the response characteristics of the system is simulated and analyzed. The results show that hydraulic press servo system which uses robust compensator has better performance than the traditional PID control and the chattering is eliminated. The test results and simulation results are compared by building simulation test system of 60MN hydraulic press electro-hydraulic proportional control system.

Abstract: The extended finite element method (XFEM) is the most effective numerical method to solve discontinuous dynamic problems so far. It makes research within a standard finite element framework and needs not mesh repartition to geometric and physical interface, so it reserves all merits of the conventional finite element method (CFEM). The XFEM was applied to the penetration process for concrete target in the paper, and the displacement mode of elements with cracks and fracture criterion were presented. Then the weak solutions of control equations were discretized in different areas. The numerical examples for steel rod penetrating in the concrete target concluded that the method and program were reasonable and effective. The effect discipline of crack growth to the concrete material penetration process was summarized, and it would establish theoretic base for the further application of the XFEM.

Abstract: Pinch valve is an important flow adjusting device in the operating system of polymer materials with characteristics of high viscosity and high solid content, and its service life limits its application and popularization. In this study, for the special application environment and requirements of clevis pinch valve in the operating system, the dual-parameter Mooney-Rivlin constitutive model of rubber and Linear Elastic model of clevis were used. The stress and strain distributions of the rubber hose, while completely closed, were obtained by means of FEM (Finite Element Method) analysis. Parameters of hose thickness and cone length of the rubber hose were optimized, and the structure-improved pinch valve was obtained as well. The strain energy release rate and fatigue life were analyzed for the improved rubber hose at the most dangerous cell.

Abstract: A kind of design scheme of PTZ control system based on DC torque motor was proposed to improve fast tracking ability and tracking accuracy of moving target. The mathematical modeling methods for each link were given and the parameters were determined with the help of engineering design method. The simulation results showed that the system had higher location accuracy, better tracking performance and could satisfy the design request.

Abstract: Domestic wind turbines with 1.5MW gearbox as the research object, application of virtual prototyping technology (ADAMS) simulation of dynamics of wind turbine gearbox when braking .According to research gear box structure, size and other parameters, using Pro / E software to create a solid model of wind turbine gearboxes. After importing to the ADAMS software, add the necessary constraints and loads, virtual prototype model of the gearbox is established. The simulation of dynamics of wind turbine gearbox are carried out by using ADAMS, and the angular velocity of the in-out shaft, gear meshing force and the vibration when braking cloud are obtained. That result is match with the theoretical value through analysis and the accuracy of ADAMS simulation is verified. The simulation results show that the design level of wind turbine gearboxes can be improved by using the virtual prototype technology and lay a good foundation for further design.

Abstract: Based on demand for power performance of electric vehicle, preliminary design of power requirement of drive motor and transmission ratio is conducted using method of theoretical calculation, simulation model of whole vehicle is established using AVL-CRUISE software, in order to improve the economy of vehicle, transmission ratio of drive system is optimized. Under the premise of ensuring power performance, economy of vehicle is improved.