Applied Mechanics and Materials Vols. 66-68

Abstract: The wear to orthogonal metals of NBR is the main cause of affecting the endurance of ESPCP. The rotational speed, load and temperature are main influence factors of the wear of 45 steel. The BP neural network model used in the forecast of the 45 steel wear volume was established. The 45 steel wear volume was obtained using friction and wear machine under different experimental parameters. The wear volumes of different experimental parameters were forecasted using BP neural network. The results indicate that it is feasible to forecast the rotational speed, load and temperature to 45 steel wear volume.

Abstract: Horizontal curves have been recognised as a significant safety issue for many years, a more important factor than road width, vertical clearance or sight distance. This study investigates the issue of speed selection through curves from several different perspectives. The relationship between safety and curve speed in SiChuan provinces was analysed using data from the local crash database. A sample of curves was selected and surveyed. Following this, acurve treatments for controlling Curve speed for different vehicles was developed based on many factors that has influence on safey.

Abstract: With high energy YAG Laser beam method, the weld ability of the TiNi shape memory alloy sheet was studied.The mechanical properties of both reference and laser welded samples were tested by stress–strain measurements. A systematic comparison of the results was carried out. Moreover, differential scanning calorimeter (DSC) investigations on samples taken from the heat affected zone and hardness measurements allowed further clarification that the modification was induced by the welding procedure. The crystal grain in welded joint is large , and new phases such as Ni₃Ti separate out.The results obtained on laser welded samples indicate the recovery mechanisms are little weakly modified by the presence of the welding zone.

Abstract: This paper presents a new-type hybrid-driven cable parallel mechanism, which combines hybrid-driven mechanism with cable parallel mechanism, and the mechanism can not only operate with high speed, high accuracy, and high payload, but also have high performance output movement. The workspace of hybrid-driven cable parallel mechanism is characterized as the space where the end-effector can reach with tensions in all cables, and it is studied in this paper. Firstly, through the kinematic analysis, it can be derived the location equations of the end-effector. Then, the paper analyzes the main factors influencing the workspace of hybrid-driven cable parallel mechanism such as cable tension, workspace of hybrid-driven mechanism, the length of cables, and the motion range. At the end, with the location equations and constraints, the workspace is determined. Computational example is provided to demonstrate the effectiveness of the proposed analysis method.

Abstract: At present, vascular stent which is a very important method to cure vascular stenosis is a hot point of study. Metal cover rate and expand level are two important elements of stent designing. In this paper, we use the method of finite element analysis to study how metal cover rate and expand level influences the properties of stent. The result shows that in the expand process, the stent that have a lower metal cover rate and expand level will expand easier, and this conclusion can be used to evaluate the designed stent. At the same time it shows that the finite element analysis is a useful method to design and evaluate the stent.

Abstract: This paper describes a support vector machine(SVM) approach to improve the test validity and accuracy for Aero-engine fault diagnosis. A new concept called classification rate has been introduced. The paper presents a new information fusion fault diagnosis method based on SVM. The diagnostic decision rules have been improved and applied to aero-engine gas path fault diagnosis. The test result manifests SVM has distinguish limitation to a strong linear correlation of two types of fault samples, it may also have diagnostic difficulties caused by Maximum number of classifications. Therefore, this paper has then proposed a corresponding solution. The simulation results verify that the method is feasible and it can reduce the defect caused by small sample data. It has high capacity of resisting disturbance and high accuracy.

Abstract: The production of polyaniline films on mild steel from sulfuric acid was carried out using cyclic voltammetry. Corrosion protection of the coating was observed in 3.5% NaCl using electrochemical impedance spectroscopy, (EIS) and potentiodynamic polarization measurements. Results showed that the polyaniline layer has the potential to protect mild steel by stabilizing the oxide layer formed on the steel surface and thus prevent the metal dissolution process.

Abstract: Inflatable antenna is a potential technique for large space deployable antenna and knowing its reflector’s deformation behavior is quite important for its accuracy improvement. A 1.5m-diameter inflatable reflector’s deformations at different internal pressures are studied using digital image correlation(DIC) in the paper. Because of the symmetry of the reflector, only two representative gores on the reflector are chosen to study. During the digital image correlation measurement, some article random dot patterns are drawn on the reflector’s surface. The 2D and 3D displacement maps of the reflector at different internal pressures are gained by DIC measurement and the cross-section of one gore of the reflector according to the internal pressure are analyzed from the measurement results.

Abstract: Since movement is an important characteristic of micro-motile cells, the development of microscopic movement tracking techniques is in urgent demand. To meet this need, applications of open source software Image-J in microscopic movement tracking were illustrated with examples. Movement track reconstruction was performed in both circular and linear movement patterns. The algorithms of real time radius, VCL (curvilinear velocity), VAP (average path velocity), VSL (straight line velocity), and other descriptive parameters using original coordinate values were developed and/or explained. Microscopic movement tracking can now be conducted at low cost using Image-J. Moreover, the algorithms can be easily controlled to fit users’ study purpose.

Abstract: One dynamical model of a thin rectangular plate subject to in-plate parametrical excitation is proposed based on elastic theory and Galerkin’s approach. At first, the undermined fundamental frequency and normal form method was utilized to study the influence of the disturbing parameters to the fundamental frequency. Secondly, the improved Melnikov expression for the oscillator was built based on the results of the undermined fundamental frequency method and time scale transformation to improve the approximate threshold value of chaotic motion in the Homoclinicity. Finally, the numerical results show the efficiency of the theoretical analysis.