Applied Mechanics and Materials Vols. 385-386

Abstract: To prolong the life of cartridge retaining pawl and link stopper in a gun cartridge retaining Mechanism, three compression springs stiffness are reduced via design study and optimization design based on dynamic analysis. Presenting the load of shell on a typical stage while entering-bore, differential equations of motion in this mechanism are established. With translational velocity of shell as the design variable, a design research and simulation analysis are made. And the relationship between shell velocity and proper shell-feed is acquired. An evaluation function is built using springs stiffness with preference-selection. With this evaluation function as the optimum objective, spring stiffness as design variables, and proper shell-feed as constraint condition, the minimum of three spring stiffness is obtained after calculation. The results indicate that compared with the original design parameters optimization results, are significantly improved with the stiffness decreased separately by 20.27%, 11.99% and 6.86%.

Abstract: The article carries on the question of the failure of the transmittal belt of the small supple-like pumping unit in Daqing oil field. But the fatigue life is not forecasted accurately. According to the characteristic that the pumping unit stands alternating dynamic load and the contact between transmittal belt and band wheel, this article established the finite element model of transmittal belt using ANSYS software. The model considered the biggest and the smallest stresses in the belt during a circle .It also established four element models in four special conditions and calculated respectively the stress in each time .Taking all the stress into considered and uniting the fatigue curve, it completed the fatigue life analysis.Through the comparative analysis with the fatigue life that the working site statisticsed in all kinds of behaviours, its error is smaller than 5%. It explains that this model is able to forecast the transmittal belt’s fatigue life more accurately. So it provides the reliable basis for making and choosing the transmittal belt.

Abstract: This article has established a three-way catalytic converter reactor model of gas phase reactions and surface reactions. Based on this model, cold start transient emission numerical simulation has been done. The result shows that the influence of ambient temperature and exhaust temperature on the HC is much greater than the impact on the CO.

Abstract: There is a great deal of uncertainty in spare parts inventory support process of aircraft hydraulic system, which cause its support decision difficult. Built integrated support decision model of the spare parts inventory based on sequence operation theory. Regard the quantity of the spare parts demand, maintenance and store as one-dimensional discrete random variable, analyzing the mutual effect among the random events utilizing addition type convolution, subtraction type convolution, and type product, thus give a dynamic description of the spare parts inventory integrated support process. Provide optimal decision basis for the spare parts inventory integrated support of aircraft hydraulic system. Results of the experimental indicated that the result of the support decision modeling consistent with the actual demand and the support decision model proved to be validated.

Abstract: Metal Rubber(MR) vibration isolator is a new type of isolator developed to overcome the fatal aging phenomenon of current rubber isolator. It has broad practical application in the military, such as aerospace. In this paper, the fatigue life experiment is conducted to MR vibration isolator, and resonant frequency and resonant accelerate transmissibility are chose as degradation parameters. It’s found that MR vibration isolator possesses jump phenomenon; resonant frequency and resonant transmissibility increase quickly to the maximum, then attenuate slowly with the increasing number of vibration. This provides fundamental basis for the design and application research of MR vibration isolators.

Abstract: Acording to the oil temperature influenced on the seal reliability, this paper put forward to the importance to study the temperature rise of the damping device. The thermodynamics of physical model of oil gas spring under the forced convection condition was established. The heat transfer coefficient expression of the correlation surface and the comprehensive heat transfer equation were deduced. After that, the external force and internal energy change rate of oil and nitrogen were researched. Through the principle of conservation of energy and the real gas state equation, the oil gas spring thermodynamic mathematical model was created. In the end, the external influence factors on the oil temperature rise were analyzed, the conclusion could be used as a reference for the design of damping device.

Abstract: This article put forward drilling mechanism reliability evaluation method on the lunar surface based on probability theory of stress-strength according to the characteristic, working environment and force condition of drilling automatic sampling mechanism on the lunar surface, ABAQUS was utilized to model and simulate the drilling automatic sampling mechanisms, and the dynamic distribution of stress of drilling automatic sampling mechanisms was obtained. According to analytic system reliability and the reliability evaluation reasonably, the optimization allocation to the use of material and system reliability can be realized.

Abstract: As the less-teeth gear has the less-teeth, the bigger helix angle and the more contact ratio etc. The research of dynamic meshing characteristics makes focus, and modal analysis is the basis of dynamic analysis. In order to get the modal analysis characteristics: firstly the parametric solid modeling is realized through the software of MATLAB and PRO/E; secondly multistage inherent frequencies and mode shapes are achieved by the finite element software of ANSYS Workbench.

Abstract: The influence of fuel properties on flame radiation transfer was investigated with numerical method under certain combustor fuel-air ratio and inlet air temperature in a gas turbine combustor. The numerical results show that the fuel properties affected the fuel pulverization quality, evaporation efficiency and combustion efficiency, which caused the flame temperature and its distribution change. Meanwhile, it has an effect on the formation and concentration distribution of soot, resulting in the changes of inner flame radiation heat flux and temperature caused by flame emitting radiation. Furthermore, the gas temperature change caused by the fuel properties more but the hydrogen content effect is relatively small, has an influence on the generation of NO which caused the change of the combustion efficiency.

Abstract: Less-teeth gear is increasingly promoted and applied because of the big single-stage transmission ratio, light weight, compact structure. The selection of gear parameters has been the key and difficult point of the design of less-teeth gear. At present design method involved in less-teeth gear design is rarely existed. According to the relationship between the characteristics and parameters of the less-teeth gear, using MATLAB for the optimization choice of the less-teeth gear, reasonable selection of the spiral angle and modification coefficient is realized, which can provide clues to further research of the less-teeth gear.