Applied Mechanics and Materials Vols. 229-231

Abstract: Frontal rail constructed of composite material was researched, in order to improving vehicle safety performance in frontal crash as well as lightweight of vehicle. Compliance to FMVSS 208, the vehicle frontal crash was simulated using the finite element model of the full vehicle. The occupant head injury was analyzed by sled test using crash pulse. Then, the composite material parameters which have the best function of reducing the occupant head injury value were studied by using orthogonal test method. Using this kind of composite materials, the occupant safety protection was effectively improved and the weight of the frontal rail was greatly reduced.

Abstract: Project the structure of the yaw elastic restriction vehicle system, and set up the system dynamic model. Establish yaw elastic restriction vehicle dynamics simulation system based on Matlab/Simulink aimed at Chery A3 sedan. Adopting the brake driving integration ESP control strategy, analyze and verify the stability control performance of independent vehicle systems and yaw elastic restriction vehicle system respectively in neutral steer, understeer and oversteer three test conditions. The results of the study show that the stability control performance of yaw elastic restriction vehicle system and independent vehicle systems has remarkable consistency. This provides a basis for vehicle driving stability control test.

Abstract: The paper has carried out numerical simulation and experimental study on the pressure loss of filter. Based on pressure loss model of filter, research methods of particulate accumulated characteristics has proposed according to the exhaust flow, exhaust temperature and exhaust back pressure. Meanwhile, the model is important for the online calculation of accumulated particulate matters in the filters and failure monitoring of diesel particulate filter.

Abstract: Engine Hood is an important part of a whole auto body panels, Structural stiffness and vibration modal always are considered while designing. After structure analysis of original engine hood, some defects were found. Based on the theories of topology optimization , topography optimization and size optimization, some constraints for the displacement, the modal, the volumetric fraction were set up, firstly, minimum strain energy was set up for the optimization objective; secondly, the minimum mass was set up for the objective. After computation, an optimized shape and material distribution for the structure was shown. Then, the structure was redesigned, and then it was computed with method of size optimization. The results of recomputation showed that the engine hood structure capability was superior to the original and the new hood weight was also reduced.

Abstract: The article introduces the vibrating test of gear box in the engineroom of 1.25MW wind turbine in wind farm in Inner Mongolia province, and obtains the detailed structure form and parameters of the wind turbine, and has real-time monitoring on four wind turbines of four typical areas in the wind farm, and gets time domain response of wind turbine. The on-line condition monitoring was applied on full power test platform that uses 1.25MW wind turbine, vibrating test was used for key parts in the engineroom of wind turbine, spindle, gearbox, generator ,generator underframe and so on, and the natural frequency of generator underframe and time and frequency domain response of gearbox, ring gear, generator and generator underframe are obtained. Through two tests, the vibration characteristic in the engineroom is obtained.

Abstract: Confirms the flow area, the minimum value of the comparative slide velocity of the floating contact point, the maximum integration curvature and the radius variation ratio as the performance indexes of PCP, discussed how the PCP’s structure parameters influence the performance indexes. Discovered that the minimum value of the comparative slide velocity of the floating contact point is proportional to the number of rotor’s threads and the coefficient of isometric radius, but is inversely proportional to the radius variation ratio; From the perspective of increasing the minimum value of the comparative slide velocity of the floating contact point, large number of rotor’s threads, big coefficient of isometric radius and little radius variation ratio is needed. But amplify the number of rotor’s threads, the coefficient of isometric radius and decrease the radius variation ratio will reduce the flow area. And amplify the number of rotor’s threads will make the maximum integration curvature greater; decrease the radius variation ratio will reduce the maximum integration curvature too. These four indexes are in contradiction to each other, structure parameters cannot make all performance indexes are optimal.

Abstract: Based on CFD numerical simulation, the effect of blade thickness on hydraulic performance was studied in DQ100-64-22 stamping and welding centrifugal pump. Six types of impellers with different blade thickness were assembled in the same pump to be investigated under design condition. The result indicates that both of head and efficiency are getting lower with the increase of blade thickness. Particularly, the downward trend is more striking when the blade thickness surpasses 2mm, but pump head decreases more gently than efficiency as the blade thickness increasing within 2mm.

Abstract: Design, simulation, flow characteristics of micro check valves used in Interstitial Fluid (ISF) devices are presented in this paper. The micro check valve includes three layers: the upper valve seat, the lower valve seat and the middle membrane layer which is fabricated by a polymeric surface micro machining process, which utilizes SU-8 as the functional material. The structure of membrane is designed as a disc with 1.2 mm diameter suspended on 4 folded beams, which work as valve springs. Maximum deformation and stress of membrane (50 μm, 100 μm, 150 μm, 200 μm, and 250 μm thicknesses) have been analyzed with ANSYS under 70 kPa. Simulation results reveal the membrane size is how to affect the performance of it. Finally, the membrane is fabricated with 150 μm SU-8 layer, and it is successfully integrated into the ISF sampling device. The forward flow and cut-off performance of the micro check valves have been observed with water. The flow curves were obtained under different forward and backward pressure. Experiment results shown that flow rates in the forward direction is small, and the flow rate is about 450 μL/min under 70 kPa; the valves can withstand more than 83 kPa pressure, and the reverse flow is nearly to zero, which meets the requirements of the ISF sampling device well.

Abstract: Effects of process parameters on friction in cold strip rolling process have been studied in this article. The prime objective is to examine the major parameters affecting the metal working process. A varying coefficient of friction through the roll contact arc has been determined. A few formulae, commonly used to predict the coefficient of friction from forward slip measurements of a rolling process, have been evaluated according to forward slip measurements and coefficient of friction data. Essentially, this article bridges the industrial constant coefficient friction approach from forward slip measurements with the academic varying coefficient of friction strategy. A systems analysis has been made regarding the effects of potentially important parameters on friction in cold rolling. Based on this analysis, the effects of a few parameters have been identified of most importance.

Abstract: To improve the precision and efficiency of rolling force prediction on hot rolled strip, a new rolling load prediction of finishing stands method was set up by fuzzy identification. It was based on T-S fuzzy model using clustering subjection functions to calculate the grade of membership for each given pattern, and using recursive least squares method to identify the consequent parameters of fuzzy model. On the basis of the measured data of the 1580 mm, the relation between the main hot strip mill parameters and rolling force was established using fuzzy model. Experimental results show that the prediction precision is higher, responds quickly and steady. The method can satisfy on line control requirements in a hot mill strip rolling process.