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Grouping the similar processes is a good approach to improve the manufacturing efficiency, however, which is facing with two difficulties of the group automation and the constraints coupling. Regarding the numerical control (NC) machines and tasks as a grid system, this paper proposes a similarity-based tactic to solve the above difficulties. First, the methodology for analyzing the similarity among NC tasks is proposed to implement group automation taking the similarity principle as theory foundation. Second, based on the results drawn from the first step, the complex constraints including similarity constraints, delivery date constraints, and serial constraints are coupled to develop an integrated scheduling model. Finally, the integrated model is solved and the optimum solution is gotten using a specialized ants algorithm.

In this paper we develop a robust controller based on sliding mode, neural network and fuzzy logic for the control of a class of under-actuated systems. The stability of the proposed controller is proved with the Lyapunov function method. Simulation results are made on an inverted pendulum.

The present paper studied the enhanced effects of O3 and KMnO4 as chemical oxidants on traditional coagulation for micro-polluted raw water treatment. Results showed that pre-oxidation using either ozone or KMnO4 could effectively improve the removal of turbidity and organic matters by coagulation. Compared with mere coagulation by polyaluminium chloride (PAC), pre-oxidation using 2 mg/l O3 for 20 minutes could increase the removal rates of both turbidity and total organic carbon by 5.33% and 5.06%. However, the effectiveness of pre-oxidation using KMnO4 was not as significant as that using O3. Besides the direct mineralization of small organic molecules into CO2 and H2O, O3 and KMnO4 could also destroy complex macromolecules in raw water. Therefore, the SUVA value of the effluent decreased markedly after the pre-oxidation and the subsequent coagulation. Based on these results, the process of chemical pre-oxidation enhance coagulation were expected to reduce the disinfection by-products formation potential.

The wind speed simulation model was given in this paper, combined with the power system analysis software (PSD-BPA) transient calculation of wind generator models, it implemented the wind speed disturbance of wind farms and the entire network voltage analysis. Combining the practical power grid in china, research on the power grid voltage fluctuation of the level after the large-scale wind farms integrated the system, and relevant the conclusions: In the process of wind disturbance, there is no angle stability of synchronous generator in the system, doubly-fed induction generator could emit and absorb reactive power, and thus could be able to maintain voltage stability.

The hydraulic cylinder should be safety released in high-pressure situations, the release valve system is presented under such situation in this paper, which can release the high pressure from the hydraulic cylinder, in order to validate its feasibility, the simulation model of pressure release system is established in AMESim, the pressure release process of which is studied, the results show that the pressure relief system can release the high pressure of hydraulic cylinder smoothly, the pressure release system verifies the pressure control performance of control system, some of the parameters or factors of pressure release system are analyzed.

Anisotropic materials have been widely applied in practical engineering problems of interest. In the paper, the anisotropic heat transfer behaviors are analyzed using the proposed hybrid finite element model with Green’s function kernel. In the established weak integral hybrid functional, the element internal field being approximated with the combination of Green’s function satisfies a priori the governing partial differential equation and the independent frame field is assumed to link the internal field. As a result, the solving linear system of equations with boundary integrals only is obtained and the constructed elements show anisotropic feature. Two numerical examples are given to show the convergence and accuracy of the proposed approach, and the effect of ply angle of orthotropic material principal direction on the temperature distribution is discussed to investigate heat transfer mechanism in anisotropic materials.

Considering the features of slope rock mass failure, this paper applies residual thrust method and linear programming theory on the basis of finite element method, to assess safety of each cell of slope rock mass in dangerous zone. According to the slip field method to determine three-dimensional slope slip surface, to deduce three-dimensional stability analysis method based on symmetry breaking, a C++ based 3D-slope program is developed for purposes of three-dimensional slope stability analysis. Finally get the most dangerous landslide geometry and its safety factor, In the paper, combining with the engineering examples, the calculating results are comfortable to the practical failure.

Process simulation is a powerful tool to predict material behaviors under specified deformation conditions, so as to optimize the processing parameters. The equation for flow stress is important to numerically analyze. However, the reported constitutive equations of magnesium alloy are only suitable for processing simulation with strain rate between 0.001-1s-1. In this paper, the strain-stress behavior of AZ31 under warm and high strain rate (>103s-1) condition has been investigated by split Hopkinson pressure bar experiments at elevated temperature. The results show that the influence of the temperature on flow stress is more obvious than that of strain rate; the flow stress decreases with the rise of temperature at a certain strain rate. Based on Johnson-Cook model, the constitutive equation of AZ31 magnesium alloy under warm and high strain rate condition has been given out by fitting the experimental data, which can be applied in process simulation of AZ31 magnesium alloy sheet forming.

This paper describes the development of a software to perform three-dimensional crack propagation analyses. The software is based on the conventional finite element method with second order tetrahedral element and an automatic mesh generation software. Hexahedral finite elements have historically been used in fracture analyses and methodologies to compute the crack parameters have been developed for the hexahedral elements. In present research, the authors have developed a VCCM (virtual crack closure-integral method) for the second order tetrahedral finite element. Use of the tetrahedral element allows us to utilize an automatic mesh generation software. The direction and rate of crack propagation are predicted based on the stress intensity factors and the shape of crack is updated. Hence, a software package containing the modules for mesh generation, for finite element analysis, for stress intensity factor evaluation, for predicting the rate and the direction of crack propagation and for updating crack configuration, can be developed.

The temperature stability of scale factor (SF) has been analyzed and tested systematically for an optical voltage sensor (OVS) based on Pockels effect in this paper. The cardinal temperature sensitive parameters in sensor head and their impacts on SF are brought out by theoretical analysis and simulation method. Corresponding experiments are arranged to verify the validity of theoretical analysis. A real-time temperature compensation system is fabricated to reduce the error of SF in temperature fluctuation environment and its effectiveness is certified by experiment.