Applied Mechanics and Materials Vol. 274

Abstract: To analyze the effect of the installation angle on the performance of axial flow fan, single blade model and whole model was established, steady flow in the axial flow fan of the 7500KW air-cooled motor was simulated by software FLUENT. Volume flow rate and hydraulic efficiency of the fan with different installation angle under specific outlet pressures were analyzed, the effect of different turbulence model on the numerical simulation results was discussed, and the effect of the single blade model, the whole model and lengthened flow passage model on the numerical calculation results was compared. The results show that the fan volume flow rate and hydraulic efficiency is higher with the installation angle of 30°, the results simulated by standard k-ε model are close to the results simulated by k-ω-SST model, calculation results of these three methods have a good agreement with each other, and the result coincides well with experimental measured values.

Abstract: This paper briefly introduces the water transfer printing craft's basic concepts and characteristics, water transfer printing technology classification, material that water transfer printing technology uses , water transfer printing process of applications and the analysis of water transfer printing technology application prospect .

Abstract: The aim of this research is to investigate the status of concept car design in china and abroad, and analysis the application of Chinese culture elements in concept car design. Based on the ergonomics principles, we refined Chinese culture elements and design a concept car which is environmental, fashionable and efficient. And we try to provide some suggestions to the Chinese elements concept car design in the future.

Abstract: Wavelet de-nosing method for complex signal is put forward in this paper. The time resolution and frequency resolution are changed as wavelet transform for signal analysis. It uses high-frequency resolution and low time resolution in low frequency analysis, and uses low-frequency resolution and high time resolution in high frequency analysis. So it fit the uncertainty principle and realize the signal time domain and in frequency domain at the same time.

Abstract: Crossed axes noninvolute beveloid gears meshing with line contact has been studied in this paper. The engagement equation and tooth profile equation have been presented by applying the theory of gearing. Meanwhile the tooth profile errors and axial errors have been calculated by means of numerical analysis and provided a theoretical way to calculate the induced normal curvature along the normal direction of the contact line in this paper.

Abstract: The principle and application of wavelet analysis and gearbox fault diagnosis are described in the paper. To the experimental measurement of gearbox vibration signal, the time-domain and frequency-domain signals are got by wavelet transform. Then it get a clearly gearbox vibration signal by wavelet de-noising. The residual signal processing and three-dimensional wavelet analysis, it get the failure frequency and determine the fault characteristics. By the experimental signal wavelet transform, it reflects that the wavelet analysis method is better than traditional Fourier transform, so it is an effective method of fault diagnosis.

Abstract: Bearing dimensionless nonlinear oil film force model is deduced based on Capone theory of cylindrical bearings in this paper. Jeffcot rigid rotor-bearing system dynamic equations are built based on nonlinear dynamics, bifurcation, chaos theory. Eccentricity increases with the speed of the system by writing MATLAB codes. It appears the periodic motion, times of periodic motion and a series of non-linear kinetics. The system eccentricity increases with a series of emergence of non-linear dynamics when speed conditions is fixed, which is the actual system design’s basis. The finite element model of gas turbine rotor-bearing system is built by ANSYS software platform in this paper. The radial bearing deformation relationship are obtained by deformation theory of centrifugal force at high speed bearing radial deformation.

Abstract: This paper investigated the status of the elderly population as well as the elderly market potential in china, and analyzed the importance of universal design on elderly electric scooters. We designed an elderly electric scooter under the guidance of universal design concept and ergonomics. Its wheelchair styling is a breakthrough which distinguishes it from the traditional electric scooter. The new scooter is safer, more fashionable and space-saving. We expect that the universal electric scooter can benefit the elderly and make the whole society concentrate on the old group.

Abstract: At present, the steel ball surface defects are usually detected by manual work, but it has low efficiency and low reliability. For the current situation, in this paper, we design the steel ball deployment mechanism based on image processing technology, establish the mathematical model of the shooting point trajectory and determine the amount and location of the shooting points by the steel ball motion analysis. By the simulation based on Mathematica and Java, verify the effectiveness of the steel ball deployment mechanism in steel ball unfolding and defects recognition. Thus, the steel ball surface can be completely detected.

Abstract: Many metal-manufacturing industries include oxyfuel gas cutting among their manufacturing processes because cutting was often used in metal-cutting processes, specifically in the large castings and forgings and the fabrication of pressure vessels. The oxyfuel gas cutting process uses controlled chemical reactions to remove preheated metal by rapid oxidation in a stream of pure oxygen. Previous research has demonstrated microstructure in heat-affected zone varied depending on the gas used for the combustion as well as the cutting speed (Vc) used during the process. In this research, 34CrNiMo6 steel of 900 mm in thickness and 45 carbon steel of 450 mm in thickness were cut using an oxygen-propane flame cutting process. Then, macroscopic morphology and microstructure test were done to analyze the influence of the thickness of cutting cross-section. The results showed, in general, the width of heat-affected zone increased with the thickness of cutting cross-section. Also, it was demonstrated that heat-affected zone in the bottom and top section was wider than others.