Advanced Materials Research Vols. 291-294

Abstract: The size selection of cables is not only to avoid the excessive heating and the danger of fire, but also to insure the service and the reliability of the concerned electric circuit. In the context of the dimension of the cables, some standards should be observed and necessary calculations should be done. With the requirement of the worldwide expansion application on Internet, the approach and the architecture of a complete Web-aided design platform are proposed for dimensioning the cables. The platform supports some calculation methods which are necessary for selecting the cables. Both XML documents and databases are used to interchange power system data and calculation results between Web servers and clients.

Abstract: In order to design the vibrator with the similar structure to military transport truck, which will be used in simulating transport environment and evaluating the transportation properties of the tested product, three-dimension model of overall structure of truck frame, crossbeams and floor is established with ADAMS/View based on multi-body dynamics theory and virtual prototyping technology. Post-processing of the simulation and analysis results is executed with ADAMS/Post Processor module with a military truck model in the study. According to the bump of vehicle during transport and the chassis vibration, the constraints, force and motion accord with the actual transport are put on the model. Vibration modes of all orders and the spectrum are gained and analyzed in detail. The results indicate that the simulation is consistent with the actual transport, which shows the simulation of the overall frame structure owns high credibility.

Abstract: Parting design, a classic work of strong experience and weak theory, has a direct impact on mold structure design and tooling. The method on the basis of case-based reasoning called CBR is one of the effective methods to solve problems of strong experience and weak theory. This paper proposes a frame of mold parting design of boat hull by UG on case-based reasoning, aimed at parting problems of telecontrolled boat hull.

Abstract: For scattered data approximation with multilevel B-spline(MBS) method, accuracy could be enhanced by densifying control lattice. Nevertheless, when control lattice density reaches to some extent, approximation accuracy could not be enhanced further. A strategy based on integration of moving least squares(MLS) and multilevel B-spline(MBS) is presented. Experimental results demonstrate that the presented strategy has higher approximation accuracy.

Abstract: In order to help the designers estimate the dynamic response of the aircraft hydraulic tubes in the working environment, a design and simulation software is developed based on CATIA and ANSYS using VB as the developing tool. This paper concentrates on the part of auto-modeling and introduces the key technologies to automatically extract the CATIA model data and build the CAE parametric model of aircraft hydraulic tube structure in ANSYS. It provides an approach to transfer a CATIA model into a CAE model conveniently which reduces the time for FE (Finite Element) analysis and makes the designers be free from the repetitious data transmission, modeling and so on.

Abstract: The paper use UG to make parametric designs of the contour of the cam, which has the advantages of high precision, better design of using parameter and simpler process. In this article, the parametric design of roller oscillating follower disc cam is taken as an example to introduce the process, getting the equation of cam contour with the help of "reversal method”, making sure of the mathematical relationship between the angle of the pendulum swing and the cam angle in terms of the constant acceleration and constant deceleration motion law. Construct the formula expression of each part for the cam profile, then get theoretical profile curve according to UG formula, and finally form the actual cam profile curve through using command of offset curve. In addition, a new cam can be made by simply changing the design parameters.

Abstract: The process simulation of virtual machining is the key technique in the CNC simulation system. So the paper talks about some useful geometric modeling techniques in simulation field, and bring forward an improved object-space separating modeling technique based on the idea of Dexel and the data-type of Z-MAP, which is a kind of geometric modeling for pieces for milling process simulation. This method is to a certain degree reduced calculation quantities in simulation, increased the speed of simulation and optimized the effect of simulation.

Abstract: Percussion drilling has been widely used in oil and gas industry, yet it still has some shortcomings, such as severe damages to drilling tools, low energy transferring efficiency and low rock-fragmenting efficiency. Thus it is necessary to reveal the mechanism of interactions between the hammer bit and rock in geophysical prospecting percussion drilling. Taking account of the coupling effect of the Weight on Bit (WOB), impact force and rotary torque, this paper constructed a Finite Element Method (FEM) model using the finite element analysis software (ANSYS/LS-DYNA) and conducted a computer simulation of bit-rock interaction under rotating and simple impact effect, which showed the rock-fragmenting process of hammer bit and the curves of volume-time and depth-time of craters as well as the effective stress-time curves of the centre tooth, second-row tooth and peripheral tooth. The results showed that: the percussion drilling process under rotating impact effect is characterized as four fundamental processes; the crater depth mainly depends on impact force rather than rotary torque; the crater created under rotating impact effect is twice the volume of that under impact effect; the effective stress of each tooth changes severely: the stress of second-row tooth is the largest, centre tooth the second, and peripheral tooth the smallest. This study provided a guide for the structural optimization of hammer bit and general applications of percussion drilling.

Abstract: Collinear load, coating with microwave-absorbing material, determined to linear accelerator (LINAC) to absorb the remnant power. It forms a part of actual accelerating structure and substitutes for traditional waveguide-type load to make the accelerating structure compacter and size smaller. In order to guarantee operational reliability, it is necessary to keep the operation frequency of cavities of the collinear load at 2856MHz and at a small shift. An approach utilized to accurately evaluate the frequency change caused by non-uniform thermal deformation is presented and a strategy for optimizing its cooling system is also described simultaneously. A six-cavity collinear load, coated with FeSiAl alloy, is researched. The results show that the frequency shift of cavities of the collinear load can be controlled within -56~35kHz, when it runs on 2856MHz and 2π/3 mode and the structure of its cooling system becomes much more compact and economic.

Abstract: The carry-loading capacity of the airtight structure is important for high-speed trains. The load of air tightness has been analyzed and universal mathematical model has been built. As a calculation model, the FE Model of the vehicle body for a type of high-speed train has been established and the modal, transient analysis has been done. Different influence of load parameters on the vehicle has been analyzed and compared to obtain the response characteristics of the structure. Finally, the strength of the train under different working conditions is verified, weakness is pointed out and suggestions based on the simulation test are given.