Applied Mechanics and Materials Vols. 325-326

Abstract: The boundary objects moving along a prescribed trajectory commonly appear in the applications of DEM to industrial fields. Generally, a boundary motion can be expressed as the combination of translational and rotational motion through specifying the linear and the angular velocity. However, it is unsuitable to describe the trajectory by this way because of the instantaneously changing location and velocity of the boundary during the simulation. A trajectory planning method is presented to model the arbitrarily complex route where the boundary passes through. This method has been used to predict the digging process of an excavator bucket in this paper. The simulation results show that the complex trajectory of a boundary object can be accurately depicted by the trajectory planning method, and the interaction between the moving boundary and the particle system is reasonable.

Abstract: Random vibration is being specified for acceptance tests, screening tests and qualification tests by manufacturers of electronic equipment meant for military applications, because it has been shown that random vibration more closely represents the true environment in which the electronic equipment must operate. In this paper, the simulation of the LCD panel subjected to random vibration load is done by the rectangle plate to represent the panel, the deformation and stress of LCD is analyzed by FEM method. Combined the simulation result and Taguchi optimization algorithm, we analyzed the relationship between the geometric dimensions of LCD and the dynamic response.

Abstract: In this paper, dynamic responses on radiation energy intensity of inert gas are simulated in use of software ANSYS / LS-DYNA when inert gas is stimulated by explosion of solid propellants to emit visible light. The effects for the visible light energy intensity emitted by inert gas are analyzed on different initial pressures in the inert gas container and with different igniting methods by propellants. Simulation results show that, the bigger initial pressure in the container is, the higher the peak value of visible light energy density intensity is and the better the effect of the visible light emitted by inert gas is. There are fewer effects on the peak value of visible light energy intensity emitted by inert gas with different igniting methods. However, it has an impact on the stability when inert gas emitting visible light. The stability is the best when central point of the propellant column is ignited.

Abstract: his paper adopted Pro/E5.0 to do parametric structure design and virtual assembly for the whole boat shaped grass burying rotary tilling machine. The structure and function of grass burying rotary tilling blade roller was elaborated in the paper. This paper mainly did simulation analysis about the motion track of grass burying rotary tilling blade roller. The results showed that the forward speed of the machine had significant influence on the motion track of blade roller while at the certain rotational speed and gyration radius.

Abstract: In this paper, the finite element method is utilized to research the coupling effects between the strong electromagnetic pulse and the computer box with holes. Focus on the influence law of the box size on shielding effectiveness of computer box against strong electromagnetic pulses. The relationship between the simulation resonance frequency and the theoretical results is obtained; the influence of the holes shape and size on shielding effect is also obtained. It is concluded that the computer boxs shielding effect is poor under the resonance frequency, and there is no linear relationship between shielding effect and holes size when the frequency is determinated. The shielding effect doesnt become worse with the holes size increasing.

Abstract: Using nonlinear energy sink absorber (NESA) is a good countermeasure for vibration suppression in wide board frequency region. The nonlinear normal modes (NNMs) are helpful in dynamics analysis for a NESA-attached system. Being a primary structure, a cantilever beam whose modal functions contain hyperbolic functions is surveyed, in case of being attached with NESA and subjected to a harmonic excitation. With the help of Galerkins method and Raushers method, the NNMs are obtained analytically. The comparison of analytical and numerical results indicates a good agreement, which confirms the existence of the nonlinear normal modes.

Abstract: This article presents the bending calculus of the circular tapping plates, embedded at the interior circumference, free at the exterior circumference, charged with an uniform vertical load at the all the crown, using the Transfer-Matrix Method. This method had the mathematical bases in the theory of Diracs and Heavisides functions and operators. The circular plates calculus is very important for its applications in the mechanical, robotic, medical, military and aerospace industries. First, we can obtain the state vector for the first ring, the exterior circumferential element and the state vector for the latest ring, the interior circumferential element. After, we can calculate for the values r₀

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