Applied Mechanics and Materials Vol. 187

Abstract: A two dimensional axisymmetric finite element analysis is preformed using AUTODYN-2D hydrocode, to simulate the dynamic response of explosive, named PBX9404 which is located behind double-shell, by the impact to shell surface resulted from high velocity spherical projectile. Simulation results shows that shock to detonation transition occurs when impact velocity is between 3.6~3.9km/s; but when the velocity increases to 4~4.3km/s, projectile will break up into pieces and the surface momentum density of debris cloud to second shell will decrease dramatically so no shock to detonation could occur. When the velocity further elevates to 4.4 km/s and above, projectile kinetic energy will cover the energy of projectile break-up, and also provide sufficient energy to further increase the surface momentum density of debris cloud, with a result that shock to detonation can be observed again. In conclusion, there is a velocity blind zone in shock to detonation of high velocity projectile to double-shell charges.

Abstract: This paper presents a kind of simulation program of aero-generator, that inverter adopts a computer-controlled manner to simulate actual working features of aero-generator, based on test platform status of aero-generator. And design of the structure of simulation system , analyze the working principle of aero-generator, and then set up simulation model of three-stage brushless aero-generator under SIMULINK. Finally ,simulation results show the accuracy of this program.

Abstract: To solve the problem of ground simulation of aerocraft attitude in hardware-in-the-loop simulation (HILS), recurrence of aerocraft attitude is realized using dSPACE emulator and three-axis turn table. The hardware configuration and key technologies of control system are introduced. Construction and downloading of the dynamic model is done in dSPACE monitor computer, the model is calculated in dSPACE emulator. The communication between dSPACE and turn table is settled with serial-port of DS4201s card. The rotate motion of the inner middle and outer axis correspond to the three-channel motion of the aerocraft body. Simulation results indicate that dSPACE finish calculating complicated dynamic model, sending and receiving velocity data through serial-port is proper, bandwidth of turn table satisfies the need of simulation. Real rotating velocity of turn table is displayed using Controldesk tools, and fits well with the digital simulation data in pitching yawing and rolling directions, and the need for real-time attitude simulation in HILS is satisfied.

Abstract: The driving range of electric vehicles is less than traditional vehicles due to the restriction of energy storage. It is raising the efficiency of each power component that is one of increasing electric vehicle driving range methods. A particle swarm optimization is used to optimize transmission gear ratio on established electric vehicle power component models. A simulation that simulates the energy consumption of vehicle after gear ratio optimization is given to compare with the actual energy consumption data of the vehicle before gear ratio optimization. The results show that the energy consumption and driving range of the latter are better than the former therefore this optimization is valid.

Abstract: It is easy to generate the separation of the flow in the stern when the ship is in oblique motion, and the flow around the hull is complex. In this article, the viscous flow around a tank in oblique motion is simulated using viscous method, and the maneuvering hydrodynamic forces are calculated and compared with experimental results. It is shown that the present method of the numerical simulation is feasible.

Abstract: We analyze the overall operation process and storage model of U-shaped curve rail type AS/RS, put forward an optimization designing method based on minimal operating time, set up a mathematical model, and make verifications using genetic algorithm which show that this optimization method greatly increases the operating efficiency of U-shaped curve rail type AS/RS, and provides a powerful reference for its application.

Abstract: For researching the paper sheet bonding and break characteristics, hardwood pulp, bamboo pulp and softwood pulp were used to form sheet, and beating degree, basis weight and PAM were changed to research the influence on elastic modulus and the specific value of yield strength to break strength. The result shown that beating degree, basis weight and PAM have influence on elastic modulus and have minor influence on the specific value

Abstract: A simplified nonlinear model in time domain and a linear model of hydro-pneumatic suspension in frequency domain were established and the expression of static stiffness and dynamic stiffness of hydro-pneumatic suspension were derived out. The expression of dynamic stiffness contains the static stiffness. Equivalent static stiffness rises with tire stiffness increasing, with the pressure of non-rod cavity of suspension cylinder increasing and with the initial position of suspension cylinder decreasing. Dynamic stiffness related to frequency increases dramatically as the frequency increases. The concept of the dynamic stiffness was proposed. The vibration characteristics of hydro-pneumatic suspension in the view of frequency domain can be analyzed and it is the reference to analyze the stiffness characteristics for suspension.

Abstract: A shear punch test is a very useful small specimen test method for evaluating the mechanical properties of in-service components, in view of the requirements of small size sample material. This paper presents the results of shear punch tests on five grades of steels used in boiler construction, along with the correlation with yield stress and ultimate tensile stress obtained ASTM standard specimens. The design of the shear punch fixture and procedure to carry out the shear punch test is also highlighted.