Applied Mechanics and Materials Vols. 333-335

Abstract: This study used spatial measurement and statistics methods to investigate spatial relationship between ore deposits and fractures in Liaoning province of China. Firstly, bivariate J function found that the ore deposits have a clustering trend around the fractures. Secondly, a conditional intensity formula for ore deposits based on Poisson process was used to model the ore deposits spatial dependence on the fractures, and the formula of model was fitted in statistics software called R. Finally, the fitted model was used to predict high intensity areas of buried ore deposits based on locations of visible fractures, which could be used to guide ore deposit exploration.

Abstract: In order to measure the equilibrium surface tension of blended fuels, a tensiometer based on maximum bubble pressure method was built. Microscope was used to measure the capillary internal diameter precisely. And the operation guidelines of the tensiometer were calibrated by purified water to improve its accuracy. Then, the equilibrium surface tensions of bio-ethanol diesel fuels were investigated at a wide range of temperature and mass fractions. Results show that surface tension of blend fuels decrease linearly as temperature increases and decrease monotonically while ethanol mass fraction increases.

Abstract: Dynamic characteristics of a bearing micro workbench are very important in the optical fiber measurement. A quantitative analysis method used for measuring the modal frequency and damping rate of the micro workbench is studied. A parameter identification method based on modal analysis is proposed. On the basis of it, a test system used for measuring the micro workbench impulse response is put up. By making use of the impulse excitation that is generated by the instantaneous change of the surface airflow, the micro bench impulse response curve is obtained. In order to improve the signal-to-noise ratio, a series of methods are utilized, such as precise trigger sampling and superposed average of multi-period data. Experimental results show that the micro workbench has a high modal frequency and a suitable damping rate, which meets the needs of the fiber measurement.

Abstract: A cost-effective method for quickly evaluating the equivalent series resistance (ESR) of electrolytic capacitors is proposed. This approach has the ability to measure the low ESR of milliohms level, meanwhile provide the pulsed testing current up to hundreds of amperes. Therefore, this method is suitable for fast inspecting the quality of bulk capacitors. The operational principle, circuit implementation and the calibration method are presented, and the performances of the prototype are tested, which validate the proposed scheme.

Abstract: In 3D butt welding of main steel structure, the accuracy of arc trajectory along the centre of seam and the distance between arc and seam are critical. Thus an accurate topography measurement system is important for controlling those parameters. In this paper, a seam topography measurement system for measuring seam topography of 3D main steel structure was developed using telecentric lens, CCD camera and diode laser. A detection algorithm was developed to detect seam topography based on grey projection integral approach. Experimental study shown that the seam topography measurement system could accurately measure the seam topography, seam width and detect seam boarder. The detection algorithm was also demonstrated with high self-verification ability.

Abstract: The paper presented a practical geo-acoustic model based on empirical formula. On the base of Hamilton geo-acoustic model, we divided seabed into two layers with semi-infinite space: settled layer and base layer. In the settled layer, velocity of longitudinal wave, density and attenuation coefficient changed with depth of the settled layer changing. This paper assumed that the settled layer had more important impact on the sound field than the base layer. Numerical calculation results show that the effective depth of the seabed is about one wavelength. The geo-acoustic model based on the empirical formula can reduce the uncertainty of sound field calculation, and provide a good way for geo-acoustic inversion.

Abstract: In order to measure the optical parameters of biological tissue accurately and non-invasive, the measurement system based on optical coherence tomography was analyzed and designed from two aspects of hardware and software. The refractive index was calibrated by standard refractive index solutions, experiments were preformed to obtain refractive index of tissue samples and scattering coefficient of Intralipid^TM solution with different concentrations. Results show that the experimental values of refractive index agree with the standard values roughly and scattering coefficient linear relate with concentration in Intralipid^TM solution. The measurement system designed in our experiment is accurate and reliable, simple and feasible.

Abstract: In order to overcome the disadvantages of traditional instrument for performance test of vibration damper, a power dissipation characteristic measurement system based on virtual instrument was developed. A fully digital test platform was constructed through the use of modular and networked data acquisition equipment. Real-time display and automatic analysis of various measuring parameters were realized. The system has higher efficiency than traditional instrument. Moreover, it is easy to expand base on this existing modular system for further testing requirement.

Abstract: In recent years, wind turbine tower buckling and blade broken often happened. Large wind turbine load and insufficient fatigue strength should be the main reasons. To prevent this case, load measurement of the wind turbine is necessary. The wind turbine load measurement is one of the type tests of wind turbine. The load of the wind turbine structure components will strongly affect the safety and life span of the wind turbine. The wind turbine load measurement can help the wind turbine manufacturer and wind farm operator to know the structural response of the wind turbine components with different load cases. According to the IEC 61400-13 standard, a method of the wind turbine load measurement is introduced in this article. Meanwhile, the measurement results are given in this article. The results indicate that the accuracy of this measurement method can fulfill the requirements of the related standards.

Abstract: On the basis of a study of measuring inclination angle with a two-dimensional accelerometer, a principle method using a three-dimensional accelerometer to measure attitude angle is analysed on the condition of micro-rotating. The method can reduce random systematic errors caused by uniaxial or biaxial output of the two-dimensional accelerometer. It can simultaneously measure both inclination angle and roll angle. So hardware selection, hardware circuit design and experiments are done: simulate the roll and tilt movement of the special objects and compare the solver results with the actual results. The principle method achieves preferable results, and provides a theoretical support for attitude determination of a particular industry as well.