Showing papers in "Applied Mechanics and Materials in 2013"
TL;DR: A review on the mother wavelet selection methods with particular emphasis on the quantitative approaches is presented in this paper, where a new technique to determine the optimum mother wavelets specifically for machinery faults diagnosis is also presented.
Abstract: Wavelet analysis, being a popular time-frequency analysis method has been applied in various fields to analyze a wide range of signals covering biological signals, vibration signals, acoustic and ultrasonic signals, to name a few. With the capability to provide both time and frequency domains information, wavelet analysis is mainly for time-frequency analysis of signals, signal compression, signal denoising, singularity analysis and features extraction. The main challenge in using wavelet transform is to select the most optimum mother wavelet for the given tasks, as different mother wavelet applied on to the same signal may produces different results. This paper reviews on the mother wavelet selection methods with particular emphasis on the quantitative approaches. A brief description of the proposed new technique to determine the optimum mother wavelet specifically for machinery faults diagnosis is also presented in this paper.
168 citations
TL;DR: In this paper, the concept of correlation coefficients of interval valued neutrosophic set (INS) was introduced for the first time, and the first numerical examples are presented in the paper.
Abstract: In this paper we introduce for the first time the concept of correlation coefficients of interval valued neutrosophic set (INS for short). Respective numerical examples are presented.
141 citations
TL;DR: In this article, a two-stage design method for base isolation structures including simplified estimation and time history analysis was proposed, where simplified estimation is used in preliminary design stage for estimating the weight and first period of an isolated structure, the upper structure is simplified as a SDOF system.
Abstract: Two-stage design method for base isolation structures includes simplified estimation and time history analysis. Simplified estimation is used in preliminary design stage for estimating the weight and the first period of an isolated structure, the upper structure is simplified as a SDOF system. According to the expected response reduction goals and response spectrum, the first period of the isolated structure, stiffness of isolation device and number of isolation bearing can be induced. Time history analysis is employed in detail design stage, for determination and optimization of isolation device based on current standards. The author has made it realized based on the old Seismic Code. As there are some changes of provision on base isolation analysis in new code, including the value of bearing stiffness and safety factor, etc., the method mentioned above should be updated. Numerical investigation shows that for regular multi-storey frame structures, the difference of the maxium ratio of floor shear between the old and new Seismic Code increase with fortification intensity.
119 citations
TL;DR: A brief introduction of PET is given in this paper, concentrating on the following aspects: the preparation process, the properties and the application of this product, market perspectives and some recommendations of PET industry are also discussed in this report based on the current market analysis.
Abstract: PET is a ubiquitous material in modern life which is used in diverse applications from drink bottles and film to shirts and fabrics. A brief introduction of PET is given in this report, concentrating on the following aspects: the preparation process, the properties and the application of this product. Market perspectives and some recommendations of PET industry are also discussed in this report based on the current market analysis.
101 citations
TL;DR: In this article, a new method of multi-focus image fusion based on Nonsubsampled contourlet transform (NSCT) with the fusion rule of region statistics is proposed.
Abstract: t is mostly difficult to get an image that contains all relevant objects in focus, because of the limited depth-of-focus of optical lenses. The multifocus image fusion method can solve the problem effectively. Nonsubsampled Contourlet transform has varying directions and multiple scales. When the Nonsubsampled contourlet transform is introduced to image fusion, the characteristics of original images are taken better and more information for fusion is obtained. A new method of multi-focus image fusion based on Nonsubsampled contourlet transform (NSCT) with the fusion rule of region statistics is proposed in this paper. Firstly, different focus images are decomposed using Nonsubsampled contourlet transform. Then low-bands are integrated using the weighted average, high-bands are integrated using region statistics rule. Next the fused image will be obtained by inverse Nonsubsampled contourlet transform. Finally the experimental results are showed and compared with those of method based on Contourlet transform. Experiments show that the approach can achieve better results than the method based on contourlet transform.
96 citations
TL;DR: Wang et al. as mentioned in this paper proposed an adaptive dynamic threshold improved Canny edge detection algorithm, which uses image gradient variance as the criterion of the image block according to the four forks tree principle, then uses the Otsu method to get the corresponding sub-block threshold value for each subblock and obtains threshold value matrix by interpolation, finally, gets image edge with improved edge connected algorithm.
Abstract: Traditional Canny edge detection algorithm uses a global threshold selection method, when large changes are in the background of the image and the target gray, global threshold method may lose some local edge information. For this problem, this paper therefore proposes an adaptive dynamic threshold improved Canny edge detection algorithm. The method uses image gradient variance as the criterion of the image block according to the four forks tree principle, then uses the Otsu method to get the corresponding sub-block threshold value for each sub-block, and obtains threshold value matrix by interpolation, finally, gets image edge with improved edge connected algorithm. Experimental results show that, the algorithm not only has good anti-noise performance, but also better detection accuracy.
76 citations
TL;DR: In this article, an approach to investigate the environmental impact of screw manufacturing and to choose suitable material for selected screw-making processes for the best performance with minimum environmental impact is presented.
Abstract: This study is an approach to investigate the environmental impact of screw manufacturing and to choose suitable material for selected screw-making processes for the best performance with minimum environmental impact. The parameters involved were types of material and screw-making process using the environmental data available in Asia region. The two different manufacturing approaches being evaluated were machining and forging. The types of material considered were low carbon steel, stainless steel, titanium alloy and aluminium alloy. As for machining process, the materials being considered in screw manufacturing were low carbon steel, stainless steel, titanium alloy, aluminium alloy, magnesium alloy and cast iron. The information of environmental impact are generated by SolidWorks. Sustainability tool was used in the formation of pair-wise comparison matrices for Analytic Hierarchy Process (AHP). Then, the ranking of global priorities had enabled the determination of appropriate material to be used for those selected screw manufacturing process. As a result, aluminium alloy was found to give minimum environmental impact for forging process whereas cast iron was found to excel in machining process. At the same time, titanium alloy was not suggested to be used in either process.
65 citations
TL;DR: In this article, a microstructural model of surface layer of machine elements from a non-uniform material is developed and a calculation scheme that includes basic structural elements is created.
Abstract: A microstructural model of surface layer of machine elements from a nonuniform material is developed. With using of this model a calculation scheme that includes basic structural elements is created. Each element is characterized by the following properties: density, elastic modulus, thermal conductivity, linear expansion coefficient and Poisson's ratio. A mathematical model of surface layer of machine elements from a sintered nonuniform material is formulated on the basis of solution of two-dimensional heat-conduction and elasticity problems by the finite-element method. The created algorithms for solution of these problems are used for formation of an automated system for thermal strength calculations. This system is surrounded with some original techniques which provide the investigation of the stress-strain state of surface layer of machine elements from a sintered nonuniform material.
59 citations
TL;DR: A broad classification of the most commonly used welding processes for dissimilar materials is presented in this article, with examples of common material combinations, critical factors for good welding, and practical difficulties arising from the physical and chemical properties of materials.
Abstract: The welding of dissimilar materials finds a wide variety of applications in the fields of industrial construction and manufacturing, where the characteristic features of the different materials are optimized for the desired application to result in cost effectiveness and value addition. Non-fusion welding methods such as solid state welding and high energy beam welding are more popular for welding dissimilar metal combinations, due to fewer complications, than fusion welding, which melts the base metal and forms brittle intermetallic compounds (IMCs) that may lead to failure. Various factors have to be considered when assessing the feasibility of welding dissimilar metals and producing a sound weld joint. This paper presents a broad classification of the most commonly used welding processes for dissimilar materials, discusses some of the commonly used welding processes with examples of some common material combinations, critical factors for good welding, and practical difficulties arising from the physical and chemical properties of materials. From the findings, it can be inferred that continuous improvement and research is still required in the field of dissimilar metal welding, particularly in the light of increasing demand for tailored material for modern engineering and industrial applications.
58 citations
TL;DR: In this paper, the development of the concept of sustainable development has been made extremely limited progress in view of what is happening further aggravation of poverty and environmental degradation, and the global community requires an innovative approach of building business and education in general.
Abstract: For two decades, the development of the concept of sustainable development has been made extremely limited progress in view of what is happening further aggravation of poverty and environmental degradation. The global community requires an innovative approach of building business and education in general. The building complex has a special role in the functioning of the economy, as it creates the material basis of all its branches , determines the character of the country for a long period and forms the living environment of the population. Consider what innovations will be needed in the coming period.
56 citations
TL;DR: An overview of key machine vision system, and demonstrates some machine vision applications will be proposed in this paper.
Abstract: With the development of modern industry, manual labor has been far from meeting the needs of modern industry. In recent years,with the development of artificial intelligence algorithms and other related field. Machine vision has been applied in a wide field of industry. An overview of key machine vision system, and demonstrates some machine vision applications will be proposed in this paper.
TL;DR: In this article, the authors used the generalized Riccati transformation and the inequality technique to obtain sufficient conditions for the third-order nonlinear neutral delay dynamic equations on time scales.
Abstract: The oscillation for certain third-order nonlinear neutral delay dynamic equations on time scales is discussed in this article. By using the generalized Riccati transformation and the inequality technique, three new different sufficient conditions which ensure that every solution is oscillatory or converges to zero are established. The results obtained essentially generalize and improve earlier ones.
TL;DR: In this paper, a systematic analysis of standards of "green" building and the existing methodologies for life cycle assessment back is discussed in order to ensure sustainable development of the territory and incentives to increase the green building by improving the competitiveness of the buildings that have higher environmental and economic performance at all stages of the life cycle.
Abstract: Purpose - to ensure sustainable development of the territory and incentives to increase the "green" building by improving the competitiveness of the buildings that have higher environmental and economic performance at all stages of the life cycle. A systematic analysis of standards of "green" building and the existing methodologies for life cycle assessment back. Developed and studied environmental-economic model of the life cycle of the building effectively, by identifying and organizing the quantitative and qualitative characteristics and to calculate the total cost of the building. These issues are discussed in this article.
TL;DR: The Direct Optimized Probabilistic Calculation (“DOProC”), which uses a purely numerical approach without any simulation techniques, provides more accurate solutions to probabilistic tasks, and, in some cases, to considerably faster completion of computations.
Abstract: Reliability of load-carrying structures has been assessed by various calculation procedures based on probability theory and mathematic statistics, which have been becoming more and more popular. The calculation procedures are well-suited for the design of elements in load-carrying structures with the required level of reliability if at least some input parameters are random and contribute to a qualitatively higher level of the reliability assessment and, in turn, higher safety of those who use the buildings and facilities. This paper discusses application of the original and new probabilistic methods – the Direct Optimized Probabilistic Calculation (“DOProC”), which uses a purely numerical approach without any simulation techniques. This provides more accurate solutions to probabilistic tasks, and, in some cases, to considerably faster completion of computations.
TL;DR: In this article, the authors present the necessity of completion of the test stand of brake components of railway vehicles with the equivalent railway operation load simulator for the research of the wheel wear on it.
Abstract: The aim of the article is to present the necessity of completion of the test stand of brake components of railway vehicles with the equivalent railway operation load simulator for the research of the wheel wear on it. The other aim of presented research needs is to perform the analysis of the equivalent conicity as a parameter for the rail vehicles in operation ride properties prediction. The sub aims are the change of frame, wheel, braking forces load via SIMRAIL simulator program load collection performance.
TL;DR: In this paper, the spectral conditions for a graph to be Hamilton-connected in terms of the spectral radius of the adjacency matrix or signless Laplacian of the graph or its complement are established.
Abstract: Some spectral conditions for a graph to be Hamilton-connected in terms of the spectral radius of the adjacency matrix or signless Laplacian of the graph or its complement are established, and then the condition on the signless Laplacian spectral radius of a graph for the existence of Hamiltonian paths or cycles is given.
TL;DR: In this article, the effects of palm oil blending ratio on combustion process that strongly affects the vehicles performance and exhaust emissions were explored, and increased blends of biodiesel ratio is found to enhance the combustion process, resulting in decreased HC emissions with nearly equal of engine performance.
Abstract: Bio fuels based on vegetable oils offer the advantage being a sustainable, annually renewable source of automobile fuel. Despite years of improvement attempts, the key issue in using vegetable oil-based fuels is oxidation stability, stoichiometric point, bio-fuel composition, antioxidants on the degradation and much oxygen with comparing to diesel gas oil. Thus, the improvement of emissions exhausted from diesel engines fueled by biodiesel derived from palm oil is urgently required to meet the future stringent emission regulations. Purpose of this study is to explore how significant the effects of palm oil blending ratio on combustion process that strongly affects the vehicles performance and exhaust emissions. The engine speed was varied from 15003000 rpm, load test condition varied by Dynapack chassis dynamometer from 050% and palm oil blending ratio from 515vol% (B5B15). Increased blends of biodiesel ratio is found to enhance the combustion process, resulting in decreased the HC emissions with nearly equal of engine performance. The improvement of combustion process is expected to be strongly influenced by oxygenated fuel in biodiesel content.
TL;DR: In this article, a vehicle dynamical properties are determined with the help of this analysis during a new vehicle design, or renewal of an older existing vehicle, and the aim of a dynamical analysis is not only to judge the influence of an excitation on the mechanical system, but also to propose and perform the construction changes of a vehicle for the detected negative state elimination or improvement.
Abstract: The analysis of mechanical systems (for example the mechanical systems of vehicles) vibration is permanently very topical. The vehicle dynamical properties are determined with the help of this analysis during a new vehicle design, or renewal of an older existing vehicle. The Eigen frequencies are characteristic for a vehicle construction. A vehicle mechanical system is excited with various types of loads in the operation and this is the reason why its individual parts oscillate. The aim of a dynamical analysis is not only to judge the influence of an excitation on the mechanical system, but also on the base of that analysis, to propose and to perform the construction changes of a vehicle for the detected negative state elimination or improvement.
TL;DR: In this paper, the application of the silent composite brake blocks of type K affords the adaptation of the braking system of the vehicle, what is cost intensive, and for existing vehicles solutions having the same friction coefficient as the cast iron brake shoes were requested (LL-Brake).
Abstract: Reduction of noise due to rolling contact of wheel and rail for fright cars is one of the principal tasks of the European railways to be solved. Experts of railways, industries and universities were engaged during the last about ten years to search for technical solutions. An important noise reduction of fright cars can be achieved by replacing the cast iron brake shoes by composite brake shoes. Doing that, two directions have been taken into consideration. This is due to the fact, that at that time most composite brake shoes were based on friction coefficients were far away from that ones of the cast iron brake shoes. Applying such friction materials on existing vehicles would have as a consequence the change of braking forces acting on the wheels. These types of brake shoes (K-block) show a friction coefficient which is higher than that one of cast iron. As a consequence the application of the silent composite brake blocks of type K affords the adaptation of the braking system of the vehicle, what is cost intensive. For these reason, the application of K-brake block was proposed for new built vehicles. For existing vehicles solutions having the same friction coefficient as the cast iron brake shoes were requested (LL-Brake doing in this way, the modification of the braking equipment of existing fright cars could be avoided.
TL;DR: In this article, the authors compare the energy and economic performances of two buildings: a real residential bioclimatic building located in Cinisi (a small town near Palermo, Sicily) and an imaginary residential building supposed having the same geographical location, cubature, shape and orientation as the real building but built by conventional building materials.
Abstract: The use of bioclimatic principles can reduce energy demands and CO2 emissions in the building sector [1-. Costs are one of the most important barriers to a widespread adoption of the green architecture technologies [4-. The aim of this study is to compare the energy and economic performances of two buildings: a real residential bioclimatic building located in Cinisi (a small town near Palermo, Sicily) and an imaginary residential building supposed having the same geographical location, cubature, shape and orientation as the bioclimatic building but built by conventional building materials. The tools used for this study were TRNSYS and HOMER
TL;DR: In this article, the authors consider a soft network shell in the presence of several external point loads concentrated at some pairwise distinct points and prove that the set of solutions of the generalized problem is non-empty, convex, and closed.
Abstract: We consider a spatial equilibrium problem of a soft network shell in the presence of several external point loads concentrated at some pairwise distinct points. A generalized statement of the problem is formulated in the form of integral identity. Then we introduce an auxiliary problem with the right-hand side given by the delta function. For the auxiliary problem we are able to find the solution in an explicit form. Due to this, the generalized statement of the problem under consideration is reduced to finding the solution of the operator equation. We establish the properties of the operator of this equation (boundedness, continuity, monotonicity, and coercitivity), which makes it possible to apply known general results from the theory of monotone operatorsfor the proof of the existence theorem. It is proved that the set of solutions of the generalized problem is non-empty, convex, and closed.
TL;DR: In this article, the chemical-looping combustion process of solid fuels has been investigated using thermogravimetric analysis (TGA), and experimental results showed that CuO showed high reactivity during reduction process with coal.
Abstract: The chemical-looping combustion process of solid fuels has been investigated using thermogravimetric analysis (TGA). Experimental results showed that CuO showed high reactivity during reduction process with coal. The coal conversion rate increased with the increase of reaction temperature, and the optimum reaction temperature was about 800 °C. When CuO was supported on TiO2, the temperature to initiate the reaction decreased and the coal conversion rate also increased. Candlenut wood ash, which contained high amount of alkali metal, displayed catalytic activity in mixtures with coal during the CLC process. A key issue is to find the ways for increasing the gasification rates during the CLC process in an industrial process.
TL;DR: In this paper, a specialized building information model implemented in a Matlab environment is designed to evaluate the energy efficiency of a building, supporting water, heat and electricity as resources consumed during the usage phase of building.
Abstract: The article describes a specialized building information model implemented in a Matlab environment. It is designed to evaluate the energy efficiency of a building. It is supporting water, heat and electricity as resources consumed during the usage phase of a building. The danger of global warming, natural resources depletion and world ecosystem collapse currently is constantly increasing. When this happens 45% of world’s energy consumption, 65% of electric power, 40% of raw materials, building industry uses 14% of potable water supply. At the same time this industry provides 35% of all carbon dioxide emissions and almost half of all solid wastes. Therefore sustainability and energy efficiency development for buildings and structures is one of the main problems of modern building industry.
TL;DR: In this article, an experimental study is conducted in a university lecture hall that has a glazed surface covering the whole wall at one end, which provides a level of internal illumination that is only sufficient for the area next to the window itself, even when the outside lighting conditions are very bright.
Abstract: The reduction of electrical energy consumption in buildings is a subject of great interest in the international scientific community. In buildings with a lot of available natural light, designed with large glazed surfaces, the artificial lighting system is often oversized and cannot be divided into segments to meet lighting demands during daylight hours.This article presents an experimental study, conducted in a university lecture hall that has a glazed surface covering the whole wall at one end, which provides a level of internal illumination that is only sufficient for the area next to the window itself, even when the outside lighting conditions are very bright. It is therefore necessary to turn on the artificial lighting system.The mathematical approach used in this paper has been successfully applied by the authors in other fields of science [1-2].Using an automatic dimmer system, the calibration of which is based on experimental measurements, the lighting is arranged in such a way as to illuminate the most disadvantaged areas of the room, and then to extend itself gradually to the whole of the room, over the period of time that the lecture hall is in use.
TL;DR: In this paper, the authors used the Hertz method to find the size and shape of the contact area as well as the normal stress distribution which has the impact on the impact of a wheel on the rail.
Abstract: An important parameter influencing the power effect of a wheel on the rail is the size and shape of the contact area as well as the normal stress distribution which has the impact on it Nowadays various methods are used to find out the size of contact areas and stresses [ It is necessary to mention the Hertz method as one of the oldest up to date used methods It provides acceptable results for a large area in spite of many simplifications Another computational procedure is the Kalker variation method [ or the strip method [ which is, thanks to its results, close to reality and is used in the following calculations Nowadays, another group of calculation program systems (ANSYS, ADINA) is used in certain situations The systems work on the base of finite elements method theory
TL;DR: The Internet of Things is currently the most popular field of communication and information research directions, and how to ensure the transmission efficiency of business information under the premise of improving networking applications data security to protect the user's privacy data will be particularly important.
Abstract: The Internet of Things is currently the most popular field of communication and information research directions. Their application in the amount of information involved, are extremely large amount of data. How to ensure the transmission efficiency of business information under the premise of improving networking applications data security to protect the user's privacy data will be particularly important. Paper uses a custom data packet encapsulation mechanism, reducing the overhead of data resources; another based on their cross-platform communication features, combined with secure encryption and decryption, signature and authentication algorithm, the establishment of a secure communication system of things model for the differentiation of things communications environment, providing a standard packet structure, namely smart business security IOT application Protocol intelligent Service Security Application Protocol (ISSAP).
TL;DR: In this article, the features of process of mine working with application of geo-walkers, defines a number of tasks for determination of parameters of an external propulsor and proves their urgency.
Abstract: The work describes the features of process of mine working with application of geo-walkers, defines a number of tasks for determination of parameters of an external propulsor and proves their urgency
TL;DR: Improved periodogram method (welch method) is used to estimate the motor imagery EEG power spectrum, with Matlab for tools, through the simulation on the experimental data, comparativing and analysising the welch method’s different spectrum estimation properties with different window functions, which provides the theoretical guidance for selecting a suitable window function.
Abstract: Welch method is a direct evolution from the periodogram method. Periodogram method is also commonly used in the power spectrum estimation, there are some inherent shortcomings in periodogram method, such as the variance and resolution of the spectrum estimation is not good, it does not satisfy the consistency estimation conditions and so on, so this paper uses improved periodogram method (welch method) to estimate the motor imagery EEG power spectrum, with Matlab for tools, through the simulation on the experimental data, comparativing and analysising the welch method’s different spectrum estimation properties with different window functions, which provides the theoretical guidance for selecting a suitable window function and makes the welch method play a good role in the EEG feature extraction.
TL;DR: In this paper, the authors deal with the way of calculation of tangential stresses over non-elliptical contact patch, where it is possible to utilize with advantage the Kalkers simplified method FASTSIM.
Abstract: The articles deals with the way of calculation of tangential stresses over non-elliptical contact patch, where is possible to utilize with advantage the Kalkers simplified method FASTSIM. This method named FASTSTRIP is adapted for non-elliptical contact area calculated by means of the Strip method. This method is almost quick as FASTSIM and the results are similar to the CONTACT results. This method may be useful for rail vehicles in track dynamics computation.
TL;DR: In this article, the effect of lithium addition on properties, physical metallurgy, various phases developed during processing of these alloys is examined, and the new developed aluminum lithium alloys series Al-Li-Cu-X are potential candidate to replace existing conventional alloys in terms of enhanced properties with reduced density.
Abstract: Significant advantages in weight reduction and increased strength have place advanced aluminum-lithium alloys at forefront of aerospace materials research. These alloys are being developed to fulfill the ever increasing need for high strength, high properties, light weight and cost effective for aerospace industry. Conventional aluminum alloys has long been in service for aerospace application. The addition of lithium to aluminum improves modulus and decrease density compared to conventional aluminum alloys. Atomic weight of lithium is 7 mass units compared to aluminum 23 mass units, hence there is density reduction of about 3% for each weight percent addition of lithium and about 6% increase in Youngs modulus. In principle weight saving for aerospace structural parts could reach up to 15 %. This paper examines effect of lithium addition on properties, physical metallurgy; various phases developed during processing of these alloys. The addition of Lithium to aluminum form coherent, low density Al3Li (δ׳) precipitates. However the binary alloys have poor mechanical properties which are attributed to strain localization and shearing of soft Al3Li (δ׳) precipitates. This problem has been solved by development of ternary and quaternary alloys containing copper and magnesium. In all aluminum-lithium alloys, small addition of zirconium or scandium is done to improve recrystallization. The new developed aluminum lithium alloys series Al-Li-Cu-X are potential candidate to replace existing conventional alloys in terms of enhanced properties with reduced density.