Advanced Materials Research Vols. 118-120

Abstract: Tractor semitrailers on high speed obstacle avoidance under emergency are likely to arise rollover or jack-knifing, which are serious risks for motorists. A dynamic stability analysis model of a three-axle tractor semitrailer vehicle is developed using the application tool. The linearized vehicle model is utilized to predict the dynamics state of the tractor semitrailer built in multibody dynamics simulation software. The lateral stability simulation for yaw rate following and anti-rollover has been performed on the dynamic model based on virtual prototyping. The results show that the lateral stability control based on tractor semitrailer proposed in this paper can stabilize the tractor semitrailer, rollover and jack-knifing can be prevented to a large extent.

Abstract: Conventional leaf spring suspension in heavy duty trucks can afford large carry capacity and better handling stability ability but less ride performance. In this paper a semi-active control was embed to the leaf spring suspension. The dynamics model of semi-active leaf spring suspension was built and analyzed. A full function heavy duty tractor using virtual prototyping was built and assembled in dynamics simulation software. A bumpy road test was performed to verify the performance of the proposed semi-active suspension. The results show that the semi-active leaf spring suspension proposed in this paper can improve the ride performance of the heavy duty trucks. The occupants in the vehicle cab will feel more comfortable.

Abstract: The purpose of this paper is to study the ability of solder joints to resist thermal fatigue. 2D simplified models of Plastic Ball Grid Array package (PBGA) structures with ten different solder joints obtained from surface mount experiment are established by finite element software, then stress-strain response of solder joints subjected to the thermal cycle load are calculated. And the effects of shape parameters of solder joints on the ability to resist thermal fatigue are discussed. Results indicate that for the same material and volume solders, the solder joints which have higher height, smaller diameter and contact angle have a stronger ability against thermal fatigue, and that the thermal fatigue characteristics are also greatly influenced by the solder outlines. Comparing with SP solder joints, LF solder joints have stronger ability against thermal fatigue.

Abstract: The reliability of kinematic trajectory of manipulators describes the ability that manipulators keep kinematic accurate. It is an important parameter to evaluate the performance of manipulators. The kinematic accuracy of manipulators can be improved when piezoelectricity material are used as a transducer to suppress the vibration of flexible manipulators. First, a 3 degree-of-freedom parallel manipulator system and its dynamic equations are introduced. The theory and experiment of a vibration suppression system are then presented. The calculation method of both error and reliability of kinematic trajectory of manipulator is further implemented. Finally, the reliability of kinematic accuracy are calculated and analyzed for the 3 degree-of-freedom parallel manipulator with or without vibration suppressing control. The results show that the reliability of kinematic accuracy is improved using vibration suppressing control.

Abstract: According to the basic principles of Kansei Engineering and BP neural network, the article establishes a non-linear relationship between the user’s perceptual evaluation and the car’s formative element. It also builds a strong anti-interference black box model, which may work out the precise value of the formative elements by the perceptual evaluations. The paper also discusses the model with deductive method, and the results show that the quantization and transformation in body design can be effectively solved by the method based on BP neural network and Kansei Engineering.

Abstract: Hybrid journal bearings are used in the high and super high speed cases mainly, such as the super-high speed spindle system. Since the bearing operates under high speed conditions, the excessive temperature rise of the bearing is a major reason to lower the accuracy of the main shaft system and limit the bearings working speed higher, as a result, restrict the bearing applications. In this paper, the thermal properties and the heat mechanism of such bearings are analyzed. The mathematical model of hybrid journal bearing is established to analyze the mechanism of generating heat. In addition, the temperature field distribution for the certain hybrid journal bearing at speed of 10000 rpm is studied by means of software ANSYS considering the heat transfer characters between fluid and solid. An improved measure about temperature rise of hybrid journal bearing is presented.

Abstract: During device applications being debugged, communications with device are need. Combining with real device brings inconvenience on debugging, and even hides bugs. Techniques and methods for debugging device applications combined with virtual device are discussed in this paper, and already proved to be feasible and effective by projects’ decrease of cost and increase of efficiency.

Abstract: Base on the study of the light reflectivity of steel surfaces, the interaction of CCD Camera and Illumination is investigated through experience. A new bright-dark filed defect recognition method which combines bright-filed mode and dark-filed mode is proposed. The bright-filed defect and dark-field defect on the surface of the strip steel can be detected at the same time through this new way, and the quantity of the defect information is increased. Therefore, the recognized defect type is twice the tradition way. A new algorithm of defect detection which is proper to bright-dark filed mode is proposed, too. This method is based on the image fusion. Experiment results show that detection rate of defects is more than 95% while classification rate of defects is over 85%.

Abstract: Sustainable manufacturing will be the dominate factor in the design of the future factory. Any manufacturing operation within these factories will affect the environment, be it through the waste it creates, the resources it uses, or the energy it consumes. All can be significant, but not all have been properly examined or documented. This paper presents an initial investigation into these issues related to subtractive machining and evaluates research finding against the waste hierarchy. The paper concludes by discussing the findings and presents some requirements and suggestions for the factory of the future.

Abstract: La1-xCaxVO3 composition-spread films were fabricated by combinatorial pulsed laser deposition and their thermoelectric properties were evaluated paralelly by the multi-channel thermoelectric measurement system. Concurrent X-ray analysis verified the formation of solid solution films in the full composition range (0≤x≤1) as judged from the linear variation of the lattice constants. The power factor of 0.6 µW/cm K2 was achieved in LaVO3 film at 800°C.Large thermoelectric properties in vanadium oxide system can be expected with the change of vanadium ion valence from 3+ to 2+.