Applied Mechanics and Materials Vols. 48-49

Abstract: Rotating discs are used widely as important structural elements in mechanical engineering. In order to obtain an optimal structural design, it is necessary to estimate the angular velocity and the stress distribution of a rotating disc in fully plastic state. So Large deformation and discontinuous yield analysis of rotating disks were analyzed by ABAQUS. Moreover, continuous yield, buckling and bifurcation analysis of rotating disk with discontinuous yield were studied. Then, Minidisk model is analyzed using ABAQUS.

Abstract: 408 acupoints of human body, including 362 acupoints of the fourteen meridians and 46 extra points, are the exit and entrance of the Viscera Meridians energy. The acupoints location is fundamental to study Chinese Medicine. The paper presents a new precision modeling and measuring technology for acupoints location on head-model based on machine vision. The head-model is measured fast and accurately by the structured-light scanning. The digital model of head-model can be made from the cloudy data through the acquisition, align, merge, and edit. The head-model coordinate systems based on the geometric morphometry is developed for dynamic measurement of an unfixed live head in which any acupoints coordinate can be measured. The plane is established based on the symmetric head. The curve of the plane across nose is fitted by the least-square method. The origin is acquired from the curve first derivative, which is unique and accurate. The tangent through the origin is defined as Z-axis. The line through the origin, perpendicular to the symmetric plane and XZ-plane are defined as X-axis and Y-axis respectively. Some important geometric parameters of the head-model are measured accurately by the digital model such as distance between all pairs of acupoints and interior angles from a triangulation of the acupoints in order to assistant locating the acupoints well. The proposed strategy in this study provides powerful weapons for acupoints location in Traditional Chinese Medicine.

Abstract: This paper presents an approach for digital mammograms enhancement using curvelet transform. The curvelet transform breaks the limitation of the wavelet transform and provides efficient representation of smooth objects with discontinuities along curves. It has special micro-local features which make them especially adapted to the contrast enhancement of mammographic features. A kind of nonlinear enhancing function is applied to enhance the details of mammogram according to the importance of the curvelet coefficients from different scales and angles. Results show the technique is potential to improve the accuracy of cancer breast detection.

Abstract: The artificial pollution tests are implemented on an IEC standard suspension insulator, and the leakage current waveforms and frequency characteristics were investigated under different equivalent salt deposit density ESDD and relative humidity. It was found that the peak values of the leakage current, the total harmonic distortion (THD) and the odd order harmonic components, e.g. 150 and 650Hz, were significantly correlated with the contamination condition of the insulator surfaces. Besides, a new characteristic parameter IMR，defined as the product of the peak values of leakage current by the ratio of the 3rd order harmonic components to the 13th order harmonic components, is introduced to evaluate the contamination condition on the insulator surface.

Abstract: The scattering matrix is ill-conditioned in mathematical model used in detecting the concentration of the main components of milk, so minor error will make a large impact on the results in the process of matrix operation. This paper is about how to use POWELL optimization algorithm to calculate the particle distribution function. The algorithm uses scattering theory to realize the mathematical model to detect the milk components rapidly. The simulation and the experiment results show that this algorithm is feasible.

Abstract: In order to solve the problem of path planning for mobile robot in unknown environment, improving overall performance of the planned path, a multi-constrained local environment modeling method is used in which the traversability, security, movement smoothness and goal-guiding are taken into consideration. On the basis of environment modeling, improved local path planning algorithms is proposed by combining Bug algorithm and rolling path planning algorithm. That improved algorithm contains Move to Goal behavior and Wall Following behavior, for overcoming local minimum, designed for robot using adaptive dynamic window. Simulation results show that the proposed methods have a good safety obstacle avoidance capabilities and environmental adaptability.

Abstract: In this paper, the cycloid bearing type of connection structure for the giant die forging hydraulic press’s movable beam eccentric torque test system are put forward to compare the static comprehensive error with the original movable slider structure. Through the MAC finite-element model analysis, the mode and vibration of the simultaneous balance detection bracket are obtained. The results show that the proposed type is superior to the original one.

Abstract: Measured impulsive response functions (IRFs) are inevitably contaminated with noise when a data acquisition system is used for an experimental measurement. This situation often leads to serious difficulties in identifying the modal parameters with proper accuracy. This paper presents a noise reduction method for measured IRFs based on structured low rank approximation (SLRA) so as to improve the accuracy of the modal identification. A cantilever beam experiment is used to demonstrate the performance of the proposed method. The results show that this method can remove noise from measured IRFs efficiently, and the modal parameter identifications based on the filtered IRFs are very good.

Abstract: The hybrid wind/PV pumped-storage power system is to solve the electro-problem of remote and undeveloped areas short of power. Aim to the special physical geography condition of some island, hybrid wind/PV pumped-storage power system is brought forward, which is based on traditional hybrid wind/PV power system, and which storages energy by using pumped-storage. The mathematical models of main components of the system are brought forward. The optimization method is by using improved heredity arithmetic. Aim to the island the system model is brought forward, and the optimization method is applied, which effectively uses wind and solar resource, advancing stability of system, and reducing investment and run/management of the system.

Abstract: Modeling and simulation of a grid-connected photovoltaic system (GCPS) is addressed in this paper to analyze its control performance and dynamics under changing irradiation. A circuit model of solar array considering irradiation is used to simulate its inherent characteristics and realized by a controlled current source. The controls of the GCPS and its electrical circuits are represented by user-defined and built-in components. The dynamic of the system in normal and fault conditions are dominated by its power controller and a method to set PI controller’s parameters is proposed in this paper. The model has been implemented on DIgSILENT. Simulation results are presented and compared with experiment waves to validate that proposed simulation model is effective for evaluation of the GCPS.