Applied Mechanics and Materials Vols. 201-202

Abstract: Firstly the margin-detection methods commonly used are presented in this paper. The algorithm idea is that the edge points correspond to the local maximal points of original image’s gray-level gradient. These algorithms are very sensitive to noises if these images mixed much noise, which usually leads to wrongly detect noise points as marginal points, and the real edge can not be detected as the interference action of noise. However, we perform kinds of pretreatments on these images under the MATLAB environment and adequately make use of the functions of image processing toolbox to satisfy the need of edge detection. Lastly, Combined with practical examples, the specific application of MATLAB in edge detection is analyzed in detail.

Abstract: Two large impaired reinforced concrete beams with pre-loading cracks were strengthened by the externally bonded steel frame composed with bottom steel plate and side hoop steel belts. The cyclic loading behaviors of these beams were tested to verify the effectiveness of this strengthening method specified in current Chinese design code. Based on the analyses of test results, the steel plate worked well with bonded concrete under normal service load, the hoop steel belts were necessary to prevent the peeling of bottom steel plate. The strengthened beams were effectively enhanced in flexural stiffness and ultimate resistance, and no new cracks appeared under the normal service load.

Abstract: Coal mine mobile refuge chamber, as the important equipment of underground refuge system, has a close relation to the life safety of the miners. At present, there are a lot of production refuge Chamber manufacturers, but they do not enjoy a unified standard in shape or size. This paper focuses on the establishment of the KJYF96/10 mobile refuge chamber model by Solidworks and adopts the structural finite element analysis by Simulation, drawing a conclusion of refuge chamber stress and displacement cloud chart. It is expected to offer an effective reference to improving the structure strength and reducing design costs.

Abstract: This paper conducts a comprehensive study on the optimization design for crushing mechanism of double toggle jaw crusher. The optimization aim is to reduce characteristic value of moving jaw plate, to raise capacity of jaw crusher, and to ensure entrance and outlet dimensions of jaw crusher. Firstly, formulae are derived for displacement of the topmost point and the bottommost point of moving jaw plate, and for the meshing angle between moving jaw plate and fixed jaw plate. Secondly, an optimization design model is established for the crushing mechanism. Finally, with C++ programming and half-penalty function method, an optimization design program is compiled for crushing mechanism of double toggle jaw crusher. Optimization is carried out for the crushing mechanism of PEJ900×1200 double toggle jaw crusher, and the optimization result is satisfactory. In the optimized crushing mechanism, the entrance and outlet dimensions and the maximum meshing angle and horizontal strokes of the topmost point and the bottommost point of moving jaw plate completely meet the design requirements. So, this paper makes it possible to raise the quality of double toggle jaw crusher.

Abstract: SolidWorks is a popular 3D design software．The characteristics and developing methods of SolidWorks which 3D design software are introduced, and studies the process of parametric design on SolidWorks software by using VB programming language, as well as the technologies of elaborating the program with API functions. And then combine with the crampoon elaborating the principle of process-driven method. When designing the large crampoon, we use the parametric design method to auto-form the 3D target crampoon model by constructing a interface software protype with which the crampoon demension parameters can be converted into some related program variables. That method not only improves the crampoon design efficiency and accuracy, but also provides some useful referenced experience to parametrical system design of other parts. Parametrization design has a wide application prospect in the field of mechanical parts designing.

Abstract: There is a close relationship between the stability of vehicle and the suspension. In this paper, an air spring suspension stability model is established by MATLAB/Simulink based on vehicle stability theories. This air spring suspension stability model is used to analyze the performance of air spring suspension and the stability of vehicle by the simulation of gyratory motion and linear motion, after that real vehicle tests is performed, the contrast between them will be used to judge the accuracy and effectiveness of the air spring suspension stability model. In this paper, some original data come from a sedan. The data of this paper has proved the vehicle installing the cylindrical air spring suspension, has a good stability performance.

Abstract: Multi-objective topology optimization was studied for layout and structural optimization of a large marine gear-box to minimize its weight, while guaranteeing its strength and rigidity. After determining design domain and multiple load cases, static structure stiffness and the first order natural frequency was defined as optimization objectives. Based on SIMP(solid isotropic material with penalization) method, the topology optimization model of the box structure was set up. Furthermore, by taking into account of manufacturability, the optimal structure was obtained. Comparing to the original design, the optimized box has 7.8% weight reduction, while its structure is more reasonable, indicating the method has certain theoretical and engineering values.

Abstract: An effective online handwritten numeral recognition system is designed based on the Matlab GUI interface. The coordinate locations of the handwritten numerals are recorded, from which the stroke direction variations and the 2-dimensional distance between the starting point and ending point of the numeral are obtained as the features, which are encoded into 42 bits binary sequence, and then input to the Hopfield neural network. The associative memory function of the Hopfield neural network can implement the learning and recognition of the handwritten numeral. Testing results show that the designed system has high recognition rate and fast recognition speed.

Abstract: In machining, a complete machining process system consists of the machine tool, the fixture, the tool and the part together, the various errors are also inevitable. The factor analysis approach and the statistical analysis method were put forward to study the machining accuracy on the basis of the error sources analysis of the machining accuracy, and the measures were introduced to improve the machining accuracy by using the factor analysis approach. The change laws are grasped by the analysis of the machining errors, so as to take the appropriate measure to reduce the machining error and improve the machining accuracy.

Abstract: The paper proposes a novel insulator-contour-detection-algorithm on power transmission lines images. The insulator-contour-detection-algorithm will have very important academic and practical significance in helicopter or robot patrol system on power transmission lines. The physical characteristics of insulator are analyzed in detail to obtain image features of insulator, and the Hough transform based on gradient information is used to detect the ellipse on the image. After double thresholds processing to the size of ellipse, linear fitting about the center of ellipse, template matching of the center of ellipse based on hausdorff distance, the insulator ellipse is determined. The consuming time of the algorithm is about 50 to 200 ms, so the algorithm can meet the requirement of real-time system. The experiment result approves it.