Advanced Materials Research Vols. 452-453

Abstract: Because mechanism always has the characteristic of high-reliability, long-life and small-sample, performance degradation theory is adopted to study the wear reliability of mechanism. So, firstly the degradation failure standard of mechanism is analyzed; then the distribution of performance parameters is verified by the K-S test; Furthermore, the failure probabilities are calculated based on degradation failure standard and distribution of performance parameters, in order to confirm the wear reliability distribution of mechanism; finally, an example is given to show the validity of this method.

Abstract: In this paper, a new mixed multi-layered model is put forward to study the crack problem of the functionally graded interfacial zone between tow homogeneous half-spaces. In the model, the interfacial zone is divided into some sub-layers with the properties of each layer varying in linear and exponential manners alternately. By applying Fourier transform and using the transfer matrix method, the mixed boundary problem of anti-plane fracture can be reduced to a Cauchy singular integral equation, which is solved numerically. Stress intensity factors of some examples are derived. The results show that the present model is effective and accurate and compared with the liner multi-layered model, the present one can save more CPU time in computation.

Abstract: This paper presents dynamic modeling of Ionic Polymer Metal Composites (IPMC) using passive electric network components. The dynamic model using standard electric network components is a novel approach to model the transient and steady state voltage and current characteristics of IPMCs. This leads to a global model for IPMCs with fine tunable parameters, which depend on the material properties, the manufacturing process and the physical dimensions of the actuator. The dynamic model has been verified by simulation, system identification and experimental studies.

Abstract: This paper analyses the fatigue life prediction problem for fixed plate of helicopter in the case of cyclic loading using damage mechanics methods. The material parameters are obtained by the results of the fatigue test of standard specimens. According to the theory of damage mechanics, the closed solution of fixed plate’s fatigue life is obtained. And the numerical solution is gotten through using finite element software ANSYS. Numerical solution, closed solutions and experimental results are consistent. This research provides a feasible way to predict the fatigue lives of structure members by means of damage mechanics.

Abstract: HDPE pipes，mostly buried underground, have been widely used in industry. Much research has been done on pipe property changing with time or temperature. But thermal expansion of pipe was neglected. This paper investigated the combined effect of soil load and temperature on HDPE pipe with introduction of thermal expansion. Stress and deflection variation with time of buried HDPE pipe were studied in ABAQUS. Result showed pipe temperature had great influence on buried HDPE pipe performance. Thermal stress was much larger than stress caused by soil load. And thermal expansion prevented pipe from deflecting due to soil load, which can protect HDPE pipe in applications.

Abstract: Traditionally, in order to get satisfied design data of reducer, you must cut and try again and again. Although this design data can satisfy conditions given, it is not optimal. In this paper, after establishment of target function, choice of parameters and confirmation of constraint conditions of the two-stage helical cylindrical gear reducer are systematically studied, its optimum mathematical model is set up. The reducer is designed by MATLAB Optimization Toolbox; it simplifies the computer programs and enhances the design efficiency and quality.

Abstract: This dissertation introduces the design of an off-line anonymity-controllable universal electronic cash payment system, which can prevent double spending. The system is comprised of user end system, business e-wallet system and bank electronic cash server system.

Abstract: In this paper is analyzed the behavior of parameters that characterize the process of a dynamic crack growth along the interface between the two orthotropic materials. The emphasis is placed on the application of the fracture mechanics concept for the interfacial crack that propagates dynamically, at high speed. In this work is considered the behavior of the oscillation index, the traction resolution factor and the energy factor depending on the crack tip speed and the stifnesses ratio. The oscillatory index increases with the crack tip speed and tends to infinity when the crack speed approaches the Rayleigh wave speed of the less stiff of the two materials. The traction resolution factor depends strongly on the crack speed but weakly on the stiffness ratio. The behavior of the energy factor is completely different from the behavior of the traction resolution factor. Results provided in this paper can be used as a guide for micromechanical modeling of materials.

Abstract: In this paper, a practical technique for system reliability evaluation of kinematic performance of planar linkages with correlated failure modes is proposed. Taylor series expansion is utilized to derive a general expression of the kinematic performance errors caused by random design variables. A practical limit state function for reliability analysis of the kinematic performance of planar linkages corresponding to different failure models is established. Through the reliability theory and the linear programming method the upper and lower bounds of the system reliability of planar mechanisms are provided.

Abstract: In this paper, a spectral element method (SEM) is applied to simulate the axisymmetric flow in Czochralski crystal growth. The coordinate singularity for 1/r at r=0 is avoided by using the Gauss-Radau type quadrature points for the spatial discretization. The SEM solver is validated by its application to the benchmark problems suggested by Wheeler [1]. The stream function is solved by an artificial Poisson equation with the present method. The results show that it agrees well with available data in the literatures.