Mechanical, Materials and Manufacturing Engineering

文章题目 页数

作者: Jian Feng He, Xiao Xiong Jin, Wan Ying Wang
摘要: The path of tire pattern’s impact on interior noise and vibration was analyzed. The same type tires with six kinds of different tread pattern were selected as the investigating subjects, and the interior measuring points’ vibration and noise signals of different tires were measured under full load condition. The basic theory of Wavelet Transform (WT) and its signal reconstruction principle were researched, and 1/3 octave Morlet wavelet was induced and analyzed. The vibration and noise signals of measuring points were transformed by using 1/3 octave Morlet wavelet, distribution features of vibration and noise signals of six tires with different tread pattern were made a comparison in time domain and frequency domain, and the distinct results of different tires were achieved. The advantage of WT in the aspect of time-frequency analysis for time domain signal is revealed.
作者: Shi Liang Jiang, Tie Jun Yang, Jing Tao Du, Yin Yin Hu
摘要: A frequency-tuned dynamic vibration absorber by tuning stiffness to reduce vibration at some troubled resonance frequencies of a simply supported beam structure is designed in this paper. Both theoretical and simulation analysis of vibration absorption are conducted. On the basis of analyzing bending vibration of the simply supported beam structure, inherent characteristics and frequency response characteristics of the simply supported beam system before and after being fixed dynamic vibration absorber are obtained by using the energy method with Rayleigh-Ritz procedure of flexible structure. Simulation model of the whole system, which is established by code written, is compared with the model established by finite element analysis software. Results are presented to show the efficiency of the vibration absorber, and then the effect of damping of the dynamic vibration absorber on vibration absorption is studied.
作者: Hao Liu, Wen Yan Song, Shun Hua Yang
摘要: In order to obtain more accurate simulation results and properties of combustion in supersonic combustion flow fields, modules of large eddy simulation of reactive turbulent flow and fifth-order WENO scheme was developed. Large eddy simulation of hydrogen-fueled supersonic combustion with strut injection was conducted. Simulations results compare were with experimental measurements, which including wall pressure, velocity, velocity fluctuation and temperature.
作者: Song Hai Fan, Shu Hong Yang, Pu He, Hong Yu Nie
摘要: Infrared thermograph has been applied in electric equipment inspection widely, but the visual effects of infrared images are always undesirable. Considering the limitation of low luminance,low contrast in infrared images,an enhancement method based on fuzzy Renyi entropy and quantum genetic algorithm is presented in this paper.Firstly,the contrast-sketching function presented in [1] is improved based on the idea of segmentation. Then, in order to segment the infrared image, Renyi entropy is extend to fuzzy domain considering the fuzzy nature of infrared image, and is employed to threshold the infrared image following maximal entropy principle. In order to meet the real-time demand of online monitoring, quantum genetic algorithm is employed to search the optimal parameters of the transform function. The experimental results indicate that the method can well improve the visual effect of infrared electric images.
作者: Tian Sheng Shi, Jin Yu Lu, Liu Zhen Yao, Yuan Lin Du
摘要: Tensegrity is a novel structure which attracts structure engineers’ interest because of its light weight and efficient structural behavior. Nowadays researches are mainly concentrated in the area of regular and irregular tensegrity, both of which are not suitable in many situations on account of their shapes or member length conditions. Thus, a new concept of semi-regular tensegrity was proposed in this paper. Based on the singular value decomposition of equilibrium matrix, an enumerative algorithm for the form-finding of semi-regular tensegrity was presented. According to the distribution of the minimum singular value of matrix, the configuration of semi-regular tensegrity was discovered. The obtained tensegrity was used as modulus for the generation of single curved cable-strut grid. A numerical example was illustrated to indicate that the proposed tensegrity modulus was feasible and advantageous in constructing single-curved tensegrity grid. Finally, the future research in the area of semi-regular tensegrity and its application was prospected.
作者: Jian Tang
摘要: Analytical hierarchy process method is proposed to assess financial management to realize the accurate financial management assessment in the paper. Analytic hierarchy process is a kind of hierarchical structure, which can estimate the impact of each index by determining the membership between up layer and bottom layer and gaining the weights of each index relative to assessment object. Assessment indexes of structural levels are established by analyzing the correlation of each index. Characteristic vector of the pairing comparison matrix which can be taken as the weights of assessment factors for financial management is established based on analytical hierarchy process. The weights provide a basis for rationality of finance management.
作者: Jian Ping Tu
摘要: By means of selecting evaluation procedure and evaluation methods of financial management expertise, regulators of the financial management system can know the existing problems feedback and reverse the amendment evaluation parameters, revise the problems in the evaluation program, thereby improving the reliability and validity of the evaluation system . Exploration to financial management expertise can promote the formulation of other professional skill system; building of financial management system can strengthen students' practical application of basic knowledge and realize the combination between skills and; the Practice of financial management system can improve the integration between vocational education and vocational skills; the development of financial management system can improve students' abilities in respects of professional extension, actual work capacity, practical innovation, collaboration, management, employment and entrepreneurship.
作者: Zhi Xia Qiao, Dan Tian Zhang, Yong Chang Liu, Ze Sheng Yan
摘要: The effect of austenization treatment temperature on the martensitic transformation in the 30CrNi3MoV ultra-high-strength steel was investigated by means of dilatometric measurements and microstructural observations. The results showed that the coarsening temperature of austenite grains in the 30CrNi3MoV steel is raised to about 1000°C due to the inhibition to the migration of austenite grain boundaries, not only by the fine and disperse vanadium carbides, but also by the solute atoms adsorbed near the boundaries. The martensite obtained in 30CrNi3MoV samples with different austenization temperatures varied in the structural constituent, as well as in the size. The martensite microstructures obtained in the samples austenized at relatively low temperatures were composed of both lath martensite and acicular martensite and they are small in size. Yet the microstructures in the 30CrNi3MoV samples with relatively high austenization temperatures were occupied mostly by coarse lath martensite. For the 30CrNi3MoV steel, the austenization heating temperature should be kept below 1000°C in order to achieve the optimum mechanical property.
作者: Zhen Yang, Fang Wang
摘要: In this paper, a new trajectory control approach of robot manipulator based on dynamics model was proposed. The method was a combination of the torque control and a compensator of neural network. The torque profile was updated by the previous torque profile. Errors were inevitable while the modeling for dynamics of robot manipulator, but they could be compensated by the compensation structure of ANN. As such, the trajectory tracking converged very fast and the new algorithm achieved the asymptotical convergence based on the Lyapunov’s method. Furthermore, it could enhance the performance of the adaptability. The result of simulations and experiments show that the controller can get the performance of trajectory well.
作者: Xue Yan, M. Li, Jun Li, X. Cheng
摘要: The Cu/ZrW2O8 gradient films have been deposited on silicon substrates by RF magnetron sputtering with copper and compound targets followed by annealing in argon atmosphere at 750 °C for 3 min. The three different compound targets were B1 (nZrO2:nWO3=1:2.2), B2 (nZrO2:nWO3=1:2.5) and B3 (ZrW2O8), respectively. The as-deposited gradient films were amorphous, while a post-deposition annealing at elevated temperature was required for the development of the cubic ZrW2O8. The structure and surface morphology of the gradient films were then studied using X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectrometer (EDS). The globular and slender rod crystals can be found in annealed films, which are copper and ZrW2O8, respectively. The fine gradient film should be obtained using the target B1.