Applied Mechanics and Materials Vols. 40-41

Abstract: ANSYS finite element software was utilized to simulate contact non-linear finite element analysis of chain connector for enhancing the structure strength and working life and productivity and manufacture craftwork of the existed ladder-type chain connector. Static and dynamic experiments were carried on several samples to test the broken positions of the chain connectors. The simulation results show that the main part of stress concentration is in teeth roots; experimental results also show that the teeth roots are the fragile parts in the chain connector. So experimental results conform to the results of simulation, it is reasonable for the simulation of contact non-linear finite element analysis of chain connector by ANSYS software. Then a structure of cambered surface tooth is promoted to enhance the strength and life of teeth parts, and petal-type clamps structure is adopted, that can carry out volume-producing to improve the productivity and processing precision.

Abstract: Morphing wings for winged tactical missile are gaining increasing concern for their potential to improve flight performance. However, morphing wings bring some new challenges to modeling flight dynamics due to movable components. This paper develops a set of complete nonlinear model, where some additional inertial terms are included. These terms account for the impact of morphing wing on flight states and make it difficult to study dynamic characteristics of missile. Therefore, a simplified model is deduced based on some reasonable assumptions. As a result, a longitudinal dynamic model is decoupled from the complete model. To verify the model, a numerical simulation is completed. The results show that the speed of wing changing has a notable effect on motion parameters during transition from one configuration to another, that is, the rapid wing changing means the larger amplitude and the higher frequency of motion vibration.

Abstract: This paper analyzes the origin of maintainability test sample, discusses the problems which exists in the selection process of similar maintenance tasks in GJB2072-94, provides the first level of sample grouping methods based on equipment entity and work relationship of maintenance, and also puts forward the method of maintenance task similarity degree in the second level of sample grouping by maintenance time.

Abstract: A second-order system model order reduction method for pre-stressed harmonic analysis of electrostatically actuated microbeams is demonstrated, which produces a low dimensional approximation of the original system and enables a substantial reduction of simulation time. The moment matching property for second-order dynamic systems is studied and the block Arnoldi algorithm is adopted for the generation of the Krylov subspace, which extracts the low order model from the discretized system assembled through finite element analysis. The difference between two successive reduced models suggests the choice of the order for the reduce model. A detailed comparison research among the full model and the reduced models is performed. The research results confirm the effectiveness of the presented method.

Abstract: Because the cleaning effect for beach cleaning equipments imported from abroad is not ideal．Considering the character of sand, according the theory of vibrating machine to choose the optimal parameters of vibrating sieve, make sure the characteristics of motion for the vibrating sieve. Take advantage of Flock approximation to solve base radius and eccentricity of the cam; generate theoretical profile curve of the cam directly and three-dimensional model in NX

Abstract: This paper analyzes the character and performance of the synthesized test bed on ground of small satellites. By studying several small satellite systems, the hardware and software architectures of flexible test bed are presented. The design ideas of the on-board part and the ground part of small satellite are given. The dynamic configuration for communication request/reply relation, the definition and resolution of the telemetry data signals are mainly discussed. The design and corresponding implementation are proven very effectively on the development of three small satellite systems.

Abstract: Current management of road traffic safety is featured by lower efficiency and quality in China. The paper is intended to seek a possible solution for improving the management of road traffic safety by using the systems perspective of safety from Vision Zero for reference. The situation of the management of road traffic safety is described first. Compared with traditional ideas and epidemiology-based ideas on road traffic safety, the perspective is introduced. After that, it is used in analyzing the problems in current management of road traffic safety and looking for the countermeasures for them. Different from other studies in China, the paper highlights the introduction and application of the systems perspective of safety as the leading ideas in the field.

Abstract: Pneumatic cylinders, as a long lifetime product, are used continuously under normal conditions. So Accelerated Life Testing is an important tool to get information quickly on lifetime which is achieved by subjecting the test cylinders to conditions that are more severe than the normal ones. This paper firstly analyze the failure mechanism of pneumatic cylinder, then based on the General Log-Linear relationship and Weibull distribution, describes a model for multiple stress-type accelerated life data analysis. The paper gives the parameter statistical method of the mode by using likelihood theory. Based on the test data from ALT of pneumatic cylinders which adopt four test stresses including air temperature, motion frequency, working pressure and operation velocity, the parameter of the model are fitted. According to the test data and the estimated model, the paper extrapolates the pneumatic cylinder’s lifetime information under the normal user level.

Abstract: A Micro WEDM (Micro Wire Electrical Discharge Machining) CNC system is presented in this paper. Its hardware platform adopted PC with movement control card. For Micro WEDM system is a typical multitasking and real-time system, the CNC software adopted multithread and module structure to perform the parallel tasks and real-time tasks. It also adopted fuzzy control algorithm to control the feeding speed and acceleration. Practical proved that the CNC system is not only low cost and easy to development, but also satisfied the need of Micro WEDM.

Abstract: In order to improve the steering and braking of the bulldozers, electro-hydraulic proportional control technology is adopted without change the transmission system of bulldozer, two hydraulic rams are used to control the steering and braking valves in both sides of bulldozer, one electromagnetic direction valve to select controlling side, and proportional reduced valve to control the pressure of hydraulic ram. Then Matlab/Simulink to imitate the dynamic characteristic is used, The single stick steering and braking control system designed improve the maneuverability and operating condition of bulldozer. The result of this paper can apply to practice directly and use for reference for other engineering machine as to single stick centralized control.