Applied Mechanics and Materials Vols. 37-38

Abstract: Several large scale failures of power system took place due to extreme weather disaster recent years, which aroused the consideration of power network security operation. Considering that the line failure events caused by natural disaster presented random characteristic, using Poisson distribution theory to depict the probability of line failure, a stochastic power system optimal dispatch model based on chance constraints theory was also proposed. We adopted the Differential Evolution algorithm to calculate the total loss based on Monte-Carlo simulation. The results of IEEE 9-bus case study imply that the dispatch model will give full consideration of weather effects, and provide a more reasonable dispatch plan for power system disaster prevention and reduction.

Abstract: Test paper problem is a typical multi-constrained objective optimization problem. By using genetic algorithm, this paper analyzes the initial population generation, the chromosome coding and its genetic manipulation, control parameters. Solving that by natural-coded genetic algorithm, improves test paper success rate and convergence rate. This genetic algorithm is applied successfully on NHibernate architecture, and developed "automatic test paper" Online Examination system.

Abstract: This paper proposes the strategy of developing enterprise cluster by way of establishing regional commercial alliances (RCA), gives the organization mode, analysis of structure and operation process of RCA. The purpose of RCA is enhancing the brand influence and competitiveness of enterprise cluster. This strategy will have a practical significance for promoting development of regional economy or industrial economy.

Abstract: Frame is an important truck part to connect and support engine, transmission, carriage and cab etc. It is important to analyze strength, stiffness and dynamic characteristics for frame design. This paper developed static analysis of a specific agricultural truck frame under two conditions of full load bending and reverse. The corresponding suggestions of structural modification were proposed. Then the dynamic response of truck frame caused by the external incentives was studied, namely harmonic response analysis and transient dynamic analysis. The paper not only analyzed whether the truck frame met the strength requirements, but also proposed the corresponding solutions for the possible cases of fatigue fracture and stress overloaded of the frame.

Abstract: On the basis of structural design of hoist boom of bracing-hoisting-separated barrier -clearing vehicle, its static analysis by ANSYS was studied to determine the location of insufficient strength, and the improvement methods were proposed. Taking the length and width of the slider in the hoist boom as the design parameters, a parametric model was established. The relationship between the maximum stress of the contact position of hoist boom with sliders and the dimension of slider was identified. The effective approaches to reduce the maximum stress were obtained which included increasing the length of slider or the thickness of top coverboard of basic boom.

Abstract: The structural intensity of shells structure was analyzed based on finite element method (FEM) in this paper. The expressions of structural intensity of plate in FEM were given under harmonic excitation. By using coordinate transformation, mathematical expressions of the structural intensity of shells structure in FEM were deduced. The structural intensities of a rectangular plate and combined structure of tube and plate were calculated. The vector plots of structural intensity under different excitation frequencies were analyzed. The results show that the structural intensity under different frequencies are different, the vector plots present directly the distribution and propagation of energy in shells structure.

Abstract: The paper is focused on some types of bulk cement tank truck, proposed to several research programs to improve the fluidization quality. The fluidization models of the fluidized bed were created in the CFD (Computational Fluid Dynamics) software FLUENT, which were then used for simulation for an improved fluidization process, and finally the fluidization quality was analyzed. To improve the quality of fluidization for the bulk cement tanker, the paper also synthesized all the programs which proposed and simulated in FLUENT. The simulation results show that the fluidization quality of the cement in tanker may be improved by adopting 40° side splitter board, with curve fluidization board substituting rectangle board, as well as by using larger gas inlet velocity. The improvement of their structure in the original basis of bulk materials vehicles can improve their serviceability and work efficiency.

Abstract: Fire water monitor is one of the most commonly used equipments in fire fighting. A liquamatic fire water monitor with self-swinging device was designed. The mechanism of an impeller driving four bar linkage was applied as the self-swinging device. The working principle of the liquamatic fire water monitor was introduced. The internal flow performance was simulated using Fluent software; and the influence rules on jet characteristics were analyzed by changing the cross-sectional shape and diameters of the monitor body, inlet pressure and drive set of the self-swinging device. These analyses led to the optimal structural parameters of flow channel. These simulation results will provide useful theoretical guidance for design of other types of fire water monitor.

Abstract: 3D (three-dimensional) reconstruction, the stress distribution and dynamic response characteristics of human femur are important for optimal design of human femur prosthesis. Based on the STL (Stereo Lithography) model, using the method of NURBS (Non-Uniform Rational B-Splines) surfaces modeling, 3D reconstruction of human femur has been discussed in this paper. Then the static and dynamics characteristics of the reconstructed human femur model are analyzed using finite element method. The analytical results revealed that the precision 3D model and the statics and dynamics characteristics of human femur are the key factors for the human femur prostheses design.

Abstract: The active academic basic of the shape tolerance and shape error assessment is a geometrical problem which is based on the shape tolerance zone. The research puts forward the probability distribution of the statistical roundness error on the condition of the researching about roundness error of rotor parts and does experimental measurement and data collection. In order to prove that it complies with certain probability distribution law, the fitted roundness error should gain the statistical distribution result by using mathematical statistics.