Advanced Materials Research Vol. 462

Abstract: The characteristics of stainless steel are discussed and the requirement on material for exhaust manifold is illustrated. Calculation on the exhaust manifold is carried out based on coupling of CFD and FEA software the distribution of temperature and thermal stress of exhaust manifold is demonstrated. The strength and safety factor of the exhaust manifold are evaluated, based on which the reliability of the design is confirmed

Abstract: This paper introduces a new method to obtain the copper coverage of PCB. Board-level simulation is very important in the thermal analysis and reliability design of electronic equipment. While in the process of PCB modeling, it is difficult to obtain the coverage percentage of copper in the PCB layer. By this method, the calculation of the coverage is converted to MATLAB image processing problems, is more simple than the traditional methods and the precision is higher, with strong practical.

Abstract: The clamping mechanism motion condition of die-casting machine is very important to the whole die-casting machine. In order to analyze the relationship between the output force of clamping mechanism and displacement of hydraulic cylinder, the whole clamping mechanism model is established. By the software ADAMS (Automatic Dynamic Analysis of Mechanical System) simulation, the all kinds of characteristics are got. Through the comparison, the best displacement by the output force is derived. In the end, on the basis of the result of the analysis, the stress condition of clamping mechanism confirms the rationality.

Abstract: The motion planning problem of wheeled mobile manipulator is formulated as an optimal control problem, and optimal criterions for point-point planning and multi-point planning are given, then genetic algorithm to solve the optimal problem is described. The simulation examples are accomplished for point-point planning and multi-point planning and the results show the method is effective.

Abstract: Using a 5-axis NC machining tool enables the tool to be oriented in any spatial direction to access a given point. This means interference can be avoided and the position of the tool can be optimized. This paper presents a new approach to generate gouging-free tool paths for constant scallop-height machining using 5-axis toroidal milling. We consider cutter positions, which guarantee local gouging avoidance. Based on second order approximations of the machined strip width, we present locally optimal cutting positions for cutting directions. The largest machined strip width of constant scallop height and the corresponding gouging-avoidance tool orientation are calculated. The effectiveness of the present approach is demonstrated through the comparing of tool path, velocity curve and acceleration curve of a typical sculptured surface, which generated by the present approach and the conventional constant scallop height. The results indicate that the present constant scallop-height machining achieves the specified machining accuracy with fewer and shorter tool paths than the existing tool path generation approaches. The dynamics is better, too.

Abstract: Finite element software MSC.MARC was used to analyze the residual stress of high-strength low-alloy steel suffered twin-wire SAW. The numerical simulation of the residual stress field with different twin-wire spacing was conducted. The residual stress test results under twin-wire SAW at twin-wire of 50 mm welding were compared to the simulation results, which verified the numerical simulation. The results showed that in the single-channel and twin-wire welding, the largest welding residual stress of the joints is located near the weld toe. At certain wire distances (20-100 mm) in the twin-wire welding process, increasing distance only minimally reduces welding residual stress. Thus, the effects of residual stress on two-wire spacing have been neglected in studies on the twin-wire welding process,More studies should focus on the impact of the performance and forming of the weld joint.

Abstract: The FBG sensor’s pressure sensitivity that is influenced by the metal-coated material and thickness was described, and the relationship in them was rightly gotten. the metal pipes of different material and different thickness were acted as the metal-coated in experiment, and the gap between the fiber and the metal-pipe was filled with epoxy. As indicated by the experiment, the changeable curve of the pressure sensitivity between theory equation and experiment is identical, and the FBGs sensitivities can be improved to 3~13 times.

Abstract: The process and method of reengineering design are introduced in the paper. Using the reverse engineering Imageware software, the helmet points cloud data were processed， the characteristic curve net was divided and the curve surface was reconstructed. Then the 3D model of the helmet established with Imageware was input in Moldflow. With the help of Moldflow simulating analysis software, injection molding is simulated and analyzed by calculated for helmet. According to the result of analyze fill, cool and warp, the structure of mould is optimized and designed and high quality product is obtained. The fast design for product and mold is realized.

Abstract: Specific oxygen uptake rate (SOUR), which reveals the status of activated sludge physiology and substrate metabolism by detecting respiration rate of microorganisms, is an important parameter reflecting the biological activity of activated sludge. Through the measurement of SOUR in SBR system, the SOUR variation and the correlation between SOUR and pollutant concentrations and control parameters in SBR process were studied. The result showed that SOUR can effectively reflect the biochemical reaction course of SBR process. There was better correlation between the SOUR and DO, ORP and pH in SBR process.

Abstract: Taking the generator as research object, this paper was trying to determinate the parameters of vibration stress relief with a new method by the aid of finite element software with powerful function. Firstly, size and distribution of remnant stress were determined. Then the modality analysis and harmonic response analysis were carried on the workpiece by using the kinetics analysis function of finite element method. Finally, some crucial parameters of vibration stress relief were obtained.The research method and conclusion would provide the important reference values for casting enterprise to determine technological parameters of vibration stress relief.