Advanced Materials Research Vols. 430-432

Abstract: Actuator is a very important part of vehicle active control suspension. Based on the analyses of traditional passive suspension and active suspension system, a novel vehicle active suspension with Electro-Hydrostatic Actuator (EHA) is put forward. The system consists of two parts: spring and actuator with variable control force. The actuator includes hydraulic cylinder, hydraulic pump, controller, etc. According to bond graph principle, bond graph model of EHA active suspension are built. In addition, sky-hook controller and fuzzy logic controller are designed and sky-hook control and fuzzy control active suspension are simulated using MATLAB tools. The prototype and test rig of EHA active suspension are developed and bench tests are carried out. The simulation and experimental results show that sky-hook control and fuzzy control active suspension with EHA provide better ride comfort and stability than passive suspension system.

Abstract: The wireless sensor network (WSN) is the development trend of the technology of sensor. This paper, based on the nRF905 wireless module, introduces a wireless temperature gathering and transmitting system. From RF modules and master control module, the hardware platform has been designed, beyond that, the paper introduces the temperature sensor network software design. The test show that the system is stable, and datas are reliable.

Abstract: Baishe villagers have inhabited loess pitted courtyard cave dwelling for hundreds of years in Sanyuan County of China.The sizes of local cave dwellings are mastered by field measurements, and variational regularity is summarized of average annual and monthly rainfall. By the soil routine and triaxial test, the physical and mechanical parameter is acquired with loess samples in different water content.At the same time, based on the literature datas, the relationship is established between rainfall and water content. Then, the definition of safety factor is given for loess cave dwellings in different depths, making use of the expressions of the surrounding rock loop stress and the Mohr - Coulomb intensity criterion. In the end,the variation of stability of loess cave dwelling could be analysed under different rainfall.

Abstract: Structure optimization of lower control arm was performed under three proving ground road conditions to find the best drawbead distribution. First, multi-body dynamics analysis was carried on to determine the deficiency of the lower control arm. Then shape optimization was applied based on the widely used optimization method under static loads by converting dynamic load of the three roads to equivalent static loads. Results of the new design show that the strength and stiffness were increased by 24.3% and 42.9% respectively.

Abstract: The article introduced the mathematic modeling and design method of the center distance minimum for the gear set of the spur gear primarily. Mathematic model built in the article included four independent variables, one object function, and ten bounds for the object function. It is common of the modeling and design method which is used for the new designing if the drive ration is changed.

Abstract: Numerical simulation has been carried out on the airflow field of bridge girder at construction state and completed bridge state under different wind speed and different wind angle of attack. The k-ε two-equation turbulence model is used in the numerical simulation by FLUENT. Variation of the three component coefficients can be obtained. The results show that drag coefficient and lift coefficient gradually becomes smaller and tends to stabilize, while pitch moment coefficient shows the trend of first increased and then reduced as wind speed increases. Drag coefficient and pitch moment coefficient does not change much and lift coefficient gradually becomes smaller with the change of wind angle of attack.

Abstract: The carbon fibers were subjected to liquid–phase oxidation treatment in 65% nitric acid solution. The relation between liquid-phase oxidation time and structure of carbon fibers had been assessed by LRS, XRD, SEM, and FTIR. The results indicate that smaller surface crystallites obtained by etching and more unsaturated carbon created after treatment, and corrosion enhanced with the increase of oxidation time. But nitric acid oxidation treatment does not change the bulk structure of carbon fibers. After nitric acid treated, the grooves of surface is wider and deeper compared to the original carbon fiber, When the oxidation times reach 12 hours, the surface of carbon fibers is severely damage. When the oxidation times reach 6 hours, there is not any characteristic peek in the FTIR. But after oxidation treatment for 9 hours, -COOH, -OH can be found from FTIR. So the best time for liquid-phase oxidation process is 9 hours.

Abstract: Accurate test dada is the basis of quality control in asphalt pavement construction. Comparative test is an important way to improve test operation level and guarantee the accuracy of test data. To check the condition of the SGC devices and the operator’s skill, comparative test was practiced. The test program and the analysis method to the SGC comparative test data was obtained in accordance with ASTM E691. According to the compaction degree data with SGC compaction at 100 times, two kinds of evaluate methods are compared. The results indicate that robust -statistical-method is more sensitive than ASTM E691-method.

Abstract: The rays will propagate along a curved path determined by the Fermat principle in medium with inhomogeneous refractive index distribution. To avoid the complicated computation of ray trajectories, a finite element method is extended to solve the radiative transfer problem in a one-dimensional absorbing-emitting semitransparent spherical graded index medium. A problem of radiative transfer inside a semitransparent spherical graded index medium is taken as an example to verify the method. The predicted temperature distributions are determined by the proposed method, and are compared with the results available in references. The results show that finite element method can predict the radiative heat transfer in one-dimensional absorbing-emitting semitransparent spherical graded index medium accurately.

Abstract: Combination application of touch screen with PLC has become the mainstream of modern control field, and it achieves control and monitoring to the fieldwork through the touch screen. This paper introduces a control system based on the combination of PLC and touch screen, achieves control to the transducer and fieldwork unit, meanwhile, displays the information collected on the touch screen. The system works reliably with steady performance and is easily to expand, has reached the design requirements.