Advanced Materials Research Vols. 472-475

Abstract: This paper aimed at traditional large casting with lost foam detection which has slown speed and low efficiency problems, developed a new non-contact detection method which combined digital close range photogrammetry measurement techniques and grating projection measurement techniques, fulfilled a car wind screen board lost foam 3272mm x 1205mm x 555mm online detection, has produced non-contacted online detection method. The results showed that method with fast detection speed、high efficiency, and can satisfy the large castings lost foam online non-contact detection requirements.

Abstract: In the tension leveling process, calculation of the strip elongation by the traditional method only considers the extension rate after the tension response, while ignoring elastic bending recovered, so the calculation of elongation is large enough to affect the process control accuracy. This paper considers not only the residual strain after elastic bend recovery, but also the affection of the residual deformation under plain cross-section assumption. The calculation of the elongation is less 4-10% than that of the traditional one. It shows that parameters of the tension leveling process set by the new method will be calculated accurately.

Abstract: To investigate the formability of aluminum alloy panel during the viscous pressure forming (VPF), the stress state and plastic flow of the aluminum alloy double-curved panel during VPF are analyzed by the commercial software ANAYS/LS-DYNA. The influence factors of thickness reduction are also investigated. The results show that the viscous medium is helpful to improve the uniform flow of the sheet blank. From the panel centre to the flange edge, the stress of the sheet blank turns from tensile-tensile stress to tensile-compressive stress. The stress state boundary lies at the edge of the double-curved panel. The formability of the sheet blank can be improved by controlling the blank holder pressure and drawbead height.

Abstract: This paper quantitatively analyzed the optimal design direction of refuge chamber by simulating different sizes of major parts effecting its ability to resist blast .It obtained best match program for span of the supporting structures、thickness of supporting structure in side and length of wave sheet, aiming to a lightweight designed of the refuge chamber within safety ensure.

Abstract: A novel inertial micro-switch with polymer-metal composite fixed electrode has been designed based on non-silicon surface micromachining technology. The micro-switch can sense the applied accelerations from positive z-axis. It can realize a flexible contact between the electrodes, eliminate the bouncing phenomenon and prolong the contact time. The dynamic contact simulation of the micro-switch has been implemented under the half-sine wave shock with 80g peak value, and its vertical response time is about ~80μs.

Abstract: The optimization problem of objective function that has two design variables can be converted into the minimum value problem of the objective function’s curved surface within the range of constraint function in the 3D coordinate system. By using the powerful data visualization capabilities of MATLAB, draw out the curved surface of objective and constraint functions in 3D coordinates system and make geometrical description of the two-dimensional optimization design model. Through the given examples of optimization design, it can be seen that to solve the optimization design problem through this method is efficient, easy and convenient.

Abstract: For known well the contributions of both tension-compression-ratio of material and intermediate principal shear stress to wire forming, the wire forming problem is developed based on unified strength theory. By denoting a notation of D, the unified stresses solution for wire forming is gained, which is suitable to both wire drawing and extrusion. In addition, when material has identical strength in tension and compression, the stresses solution based on unified strength theory become that based on unified yield criterion. Notably, it is proved that the stresses of wire forming are independent of the intermediate principal shear stress. Whether any yield criterion (e.g., Mises, Tresca or unified yield criterion) is adopted, for it is assumed that the tensile and compressive strength is equal to one another, the stresses solution is as same as that based on unified yield criterion, and is merely a special case of the unified stresses solution developed by this paper.

Abstract: In order to adapt to the development of world integration, most modern ocean-going vessels are engaged in long transport routes voyages, so the demand for fresh water is very large. From the energy conservation, improving the amount of water production, saving shipping companies operating costs, increasing ship endurance capacity point of view, combine the vacuum system which has the feature of less salt content with the reverse osmosis water production system which has the advantage of large water production, now we design the new type composite desalination plant, and doing the model calculation, the study has a very high prospects for the development and practical application value.

Abstract: Through to the research of technological parameter of copper plating on the surface CF, determining the best parameters: electroplating current is 200 mA, electroplating time is 1 h. Using vacuum hot-pressing sintering to make different composition sample, the sample organization been done the SEM microscopic analysis, and measured micro-hardness and density. Then doing comparative analysis. In the matrix, CF was found to be homogeneously dispersed into the metal matrix, increasing the density of the sample.

Abstract: By the experimental modal testing to the main structure of the high-speed horizontal machining center，the modal parameters such as the natural frequency, damping ratio, stiffness and mode shapes are obtained. By analyzing the vibration characteristics, the critical components of the machining center is at the spindle front bearing part and the vertical column on which the screw driving spindle box to move in vertical direction is mounted are determined, and provide an important basis of optimizing the structure for the machining center. And the amplitude-frequency characteristic curves of the critical components evaluate the dynamic stiffness as the key indicators to provide reliable data for improving processing accuracy and cutting ability of machining center.