Applied Mechanics and Materials Vols. 543-547

Abstract: The power consumption and pressure distribution of Newtonian fluid and pseudoplastic fluid in a stirred tank with stirrer composed of perturbed six-bent-bladed turbine (6PBT) were calculated by CFD combined with laminar viscosity model. The test liquid used were glycerine and 1.25% (wt) xanthan gum solution, a pseudoplastic fluid with a yield stress. Compared with the stirrer composed of six-bent-bladed turbine (6BT), the effects of the 6PBT impeller on fluid pressure distribution were extensively analyzed, and the Coriolis force role of strengthening swirling motion and efficient agitation mechanism of 6PBT impeller were made a thorough inquiry, respectively. Results show that 6PBT impeller can lead to an energy saving effect as the increasing speed, and generate a larger low pressure region in flow field at the same time, so this is more beneficial to the whole circulation. Moreover, the stronger swirling motion may emerge in stirred tank with 6PBT impeller under the action of Coriolis force, which is exceedingly advantageous to promotion of mixing efficiency. As a result, 6PBT impeller is found to have a obvious superiority on mixing process of pseudoplastic fluid. The research results provide valuable references and instructions for the development of new type impeller.

Abstract: The dynamic performance of PingQiao of abnormal high tower crane is particularly important to the whole structure. Using the finite element method to set up the finite element parametric model of PingQiao of the abnormal high tower crane, and then making dynamic analysis. Taking the analysis result as the objective function of the optimization design model,and using the optimization algorithm module of ANSYS to make dynamic optimization design of PingQiao structure,the quality of PingQiao of the abnormal high tower crane is effectively reduced, the dynamic performance of the metal structure is improved,this lays the foundation for the whole optimization.

Abstract: With closed hydraulic transmission system at Step condition as the research object,the dynamic model of variable pump driving variable motor is established under the AMESim software to study the influence of the effective bulk modulus of fluid on coupling characteristics of the hydraulic system. The simulation results show that the greater the bulk modulus is, the smaller the pressure fluctuations and the power loss are, and the faster the motor response speed is, which instructions that reasonable choice of fluid the bulk modulus can improve the stability of the hydraulic system. This paper provides theoretical guidance for the hydraulic system design and analysis of the dynamic quality of hydraulic equipment.

Abstract: An improved program of the tip clearance of a high speed engine pump based on simulation was introduced in this paper. In order to verify its reliability, a device was designed to test the performance of the pump and found that the simulation data was in good agreement with the experiment. Within the scope of work, the improved pump shows excellent performance that the head has an improvement of more than 7m averagely, the efficiency is improved by 10 % to 20 %, and the shaft power has increased about 100Wrespectively.The results confirmed that using this numerical analysis method to optimize the tip clearance of the high speed engine pump was reasonable.

Abstract: SAE J2114 test method has simulated the recurrence of passenger vehicle rollover form in the traffic accident, mainly including the rollover stage and tumbling stage. In this paper, the whole rolling process of passenger vehicle are analyzed in mechanical model by the testing method, such as the critical condition of rolling ; the condition affecting the vehicle back weeks on the air parabolic motion stage; the condition affecting rolling strength on the landing stage. Furthermore, the article has used MATLAB tools to analyze the relationship of four factors ,which are the critical speed, wheel base, center of gravity height and radius of the rolling ,and the results will help us better understand the collision shape, providing theoretical basis for accident reappearance.

Abstract: Hoist bridge crane swinging phenomenon often occurs during the operation, making the work more difficult, there is a certain danger. To solve this problem, anti-sway system for overhead cranes depth study to identify the main factors affecting heavy lifting swinging; proposed single neuron PID control strategy, while using MATLAB simulation used to verify the reliability of the method.

Abstract: The coal mine hoisting equipment is one of the most important equipmentin coal mine, largely determine the total production capacity of the mine. Compared with the international advanced level, there is a considerable gap between the many coal mine enterprises, especially the plate chain bucket elevator is more big gap.On the upgrading of equipment for technological transformation, improve reliability,economic operation, reduce the accident rate, are of great significance to the oldmine.

Abstract: Aircraft landing gear can absorb the energy generated and consumed in aircraft landing, taxiing process, thus weakening the vibration of the aircraft, flight safety plays a vital role. This paper established a landing gear dynamics modeling, its mechanical analysis, and through trial and simulation of the dynamic characteristics of the landing gear were studied, with some practical significance.

Abstract: Based on the similarity between the regularity for change of technical condition of vehicle and biological population, the paper builds a simulation model on the overall technical state of system vehicle, and hence sets up a state transition equation of vehicle service life and a transition equation of vehicle accumulated mileage to measure the number of retired vehicles in a system and study when the vehicle is retired and the quantity of retired vehicles. In the end, the paper verifies the practicability of this method through a case.

Abstract: The reliability analysis of the coal mining vehicle is expounded by the application of Reliability Centered Maintenance (RCM). According to RCM, maintenance mode and service period of the equipment are determined after a logical judgment and effective analysis of equipment reliability and malfunction results. Corresponding maintenance strategies are established. It is estimated that the strategy may be further applied in equipment maintenance strategy.