Applied Mechanics and Materials Vol. 472

Abstract: Design of new industrial objects characterized by high stylistic content often starts from sketches or images of the product to be, subsequently, represented in a 3D digital form by using CAD software. To speed up this phase, a number of methods for automatic or semi-automatic translation of sketches or images into a 3D model have been devised all over the world also for reverse engineering purposes. When the image shading is a crucial information for recovering the final 3D shape, Fast Marching is recognized to be among the best method to date, especially for frontally illuminated scenes. Unfortunately, such a method cannot be directly applied when object illumination in the considered image is oblique. The present work is aimed to propose a simple, but effective, approach for recovering 3D shape of objects starting from single side illuminated scenes i.e. for solving non-eikonal SFS problems. Tested against a set of case studies, the method proved its effectiveness.

Abstract: In this paper, in order to produce smooth curve, we design a class of n-point p-ary smooth interpolatory subdivision schemes that can reproduce polynomials of degree n-1 with approximation order n. Many classical interpolatory subdivision schemes are special cases of this kind of subdivision. We illustrate the approach with a new 5-point quaternary interpolatory subdivision scheme with two parameters, which reproduces polynomial of degree 4 with approximation order of 5 and can generate new interpolatory curves.

Abstract: In order to integrate design resources of powertrain in wheeled combine harvester chassis, and improve its design quality, the process and methods of constructing a design platform for the powertrain in wheeled combine harvester chassis is presented in this paper. Based on the characteristics of the specific knowledge of powertrains design, this paper discourses methods of knowledge gathering, sorting, classification and presentation. Meanwhile, how to use Oracle database to store design knowledge also been discussed. According to the features of different parts, using method of parametric model constructing based on Pro/E, a set of parametric models of powertrain is built. After the forming of knowledge base, the reasoning mechanism is studied. Taking Visual Studio 2008, Oracle, Pro/E as major development means, the design platform of the powertrain in wheeled combine harvester chassis is finally established.

Abstract: In order to detect fertilized eggs nondestructively to improve hatching rate, this paper uses the method of image processing and Learning Vector Quantization neural network to identify fertilized eggs. Firstly, we use image collection device to collect images of the unfertilized and fertilized eggs and extract the feature of egg image, and then determine 5 principal component characteristics of the egg shape. Learning vector quantization neural networkis 5 dimensional input and 1 dimensional outputs.Finally,we use Genetic Algorithm to optimize the weights and threshold of neural network, which can be used to predict the condition of fertilization. The experiment shows that, compared with the traditional LVQ neural network, it is more accurate to recognize the fertilized eggs when using optimized LVQ neural network by genetic algorithm. The rate can reach 98.21%, which meets therequirements of recognizing fertilized eggs.

Abstract: In this study, two new sharp perturbed midpoint inequalities are proved by establishing proper kernel functions. These results enlarge applicability of the corresponding quadrature rules with respect to the obtained error bounds. Applications in numerical integration are also given.

Abstract: Knowledge discovery (KDD) method aims to solve the problem of massive data. For bridge engineering, the structural health monitoring (SHM) system is cumulative data from time to time, but the whole system should be understudied in real time. Data mining should be used in one of the KDD process. This article proposed a regular rule of analyzing the SHM data from a real sited bridge. The data aim to help engineers understanding the system degradation of the bridge.

Abstract: Wind turbine gearbox is the key component. Because of alternating loads caused by gear engagement, variations of wind speed and fluctuation of load, it is prone to get fatigue damage, which lead to the high failure rate and low life. In this paper, obtaining the stress time histories through multi-body dynamics simulation, then base on the simulation data, statistical processing load time histories by used rain flow counting method, the last is that estimating fatigue life of components, combined with P-S-N curves of parts material and linear cumulative damage law. The fatigue life prediction of each component in gearbox would be implemented by matlab programming. Through the fatigue analysis of a megawatt-class wind turbine gearbox transmission chain, the design was verified feasibility, but not economic, and it show that this method has certain reference value and potential for improvement.

Abstract: This paper presents the application of artificial immune systems for analysis of the structural integrity of a building. Inspired by a biological process, it uses the negative selection algorithm to perform the identification and characterization of structural failure. This paper presents the application of artificial immune systems for analysis of the structural integrity of a building. Inspired by a biological process, it uses the negative selection algorithm to perform the identification and characterization of structural failure. This methodology can assist professionals in the inspection of mechanical and civil structures, to identify and characterize flaws, in order to perform preventative maintenance to ensure the integrity of the structure and decision-making. In order to evaluate the methodology was made modeling a two-story building and several situations were simulated (base-line condition and improper conditions), yielding a database of signs, which were used as input data for the negative selection algorithm. The results obtained by the present method efficiency, robustness and accuracy.

Abstract: In order to effectively reduce evacuation time of pedestrians in emergencies, a novel evacuation model is proposed based on the three-dimensional cellular automation. The model, according to Moore cellular structure, firstly defines location income and estimates evacuation time parameter, and then gives calculation formula for moving probability of pedestrians at next moment. Meanwhile, in combination with the degree of fear and moving speed, evacuation strategies and cellular evolution rules suited to the three-dimensional condition are raised. At last, by establishing simulation model, the article profoundly analyses key factors that affect evacuation time of pedestrians, and finds that the evacuation time shows a negative correlation with the exit width, but a positive correlation with pedestrian density. Appropriate increase of pedestrians fear degree is good for reducing the whole evacuation time.

Abstract: The pool fire mathematical model of hermetically closed room is built by different plume models, the time of smoke filling and smoke layer temperature are calculated combined with experimental heat release rate. Theoretical calculations are compared with the experimental results to verify the usefulness of different plume models. The results indicate that: in initial period of fire, the smoke filling speeds of four plume models are similar, and McCaffrey plume model is most close to physical processes; in later period of fire, Zukoski plume model is most close to physical processes of smoke filling; during the fire, the results of Thomas plume model and Zukoski plume model are almost identical, and Thomas model is more suitable for engineering application; the smoke layer temperature discrepancy between theoretical calculation and experimental data is huge, and the theoretical calculation method of temperature is not recommended for predicting temperature in engineering.