Showing papers in "Advances in Mechanical Engineering in 2016"
TL;DR: Computational and statistical results demonstrate that the proposed co-evolutionary particle swarm optimization outperforms most of the other metaheuristics for majority of the problems considered in the study.
Abstract: Industries utilize two-sided assembly lines for producing large-sized volume products such as cars and trucks. By employing robots, industries achieve a high level of automation in the assembly pro...
251 citations
TL;DR: It is a contradiction to homogeneous material fatigue behavior characterized by widely used linear Paris law, welded-joint fatigue issues need to be reassessed because fatigue crack growth behavior.
Abstract: It is a contradiction to homogeneous material fatigue behavior characterized by widely used linear Paris law, welded-joint fatigue issues need to be reassessed because fatigue crack growth behavior...
204 citations
TL;DR: In this article, the authors improved upon the traditional polynomial detrending method in order to correct the vibration acceleration signals with inconsistent initial velocity and displacement more rationally and efficiently.
Abstract: This study improves upon the traditional polynomial detrending method in order to correct the vibration acceleration signals with inconsistent initial velocity and displacement more rationally and efficiently. When numerical integration of recorded acceleration signals using assumed initial velocity and displacement values (which are generally inconsistent with real values) is performed, baseline shift or drift phenomenon can arise in velocity and displacement curves obtained. Baseline correction must be performed if an inconsistent acceleration signal is to be used in dynamic analyses. Polynomial detrending is generally used to remove unreasonable trends in time series, but the consistency among acceleration, velocity, and displacement has not received sufficient attention. The traditional polynomial detrending method is improved by purposefully removing the shifted trends in velocity and displacement. Two inconsistent vibration signals are selected to be corrected using both the traditional method and t...
192 citations
TL;DR: A refined spinal cord finite element method showed that all the geometrical parameters are involved in the spinal cord contusion mechanisms, and spinal cord injury criteria must be considered at each vertebral level.
Abstract: Traumatic spinal cord contusions lead to loss of quality of life, but their pathomechanisms are not fully understood. Previous studies have underlined the contribution of the cerebrospinal fluid in spinal cord protection. However, it remains unclear how important the contribution of the cerebrospinal fluid is relative to other factors such as the white/gray matter ratio. A finite element model of the spinal cord and surrounding morphologic features was used to investigate the spinal cord contusion mechanisms, considering subarachnoid space and white/gray matter ratio. Two vertebral segments (T6 and L1) were impacted transversely at 4.5ms-1, which demonstrated three major results: While the presence of cerebrospinal fluid plays a significant contributory role in spinal cord protection (compression percentage decreased by up to 19%), the arachnoid space variation along the spine appears to have a limited (3% compression decrease) impact; Differences in the white and gray matter geometries from lumbar to thoracic spine levels decrease spinal cord compression by up to 14% at the thoracic level ; Stress distribution in the sagittal spinal cord section was consistent with central cord syndrome, and local stress concentration on the anterior part of the spinal cord being highly reduced by the presence of cerebrospinal fluid. The use of a refined spinal cord finite element method showed that all the geometrical parameters are involved in the spinal cord contusion mechanisms. Hence, spinal cord injury criteria must be considered at each vertebral level.
167 citations
TL;DR: In this paper, an overview of common failure modes of rotating machinery is provided along with the most relevant degradation mechanisms and their application for prognostics are discussed, while the majority of the research in health condition monitoring focuses on data-driven techniques, physicsbased techniques are particularly important if accuracy is a critical factor and testing is restricted.
Abstract: Health condition monitoring for rotating machinery has been developed for many years due to its potential to reduce the cost of the maintenance operations and increase availability. Covering aspects include sensors, signal processing, health assessment and decision-making. This article focuses on prognostics based on physics-based models. While the majority of the research in health condition monitoring focuses on data-driven techniques, physics-based techniques are particularly important if accuracy is a critical factor and testing is restricted. Moreover, the benefits of both approaches can be combined when data-driven and physics-based techniques are integrated. This article reviews the concept of physics-based models for prognostics. An overview of common failure modes of rotating machinery is provided along with the most relevant degradation mechanisms. The models available to represent these degradation mechanisms and their application for prognostics are discussed. Models that have not been applied...
166 citations
TL;DR: The proposed rule is more effective to perform fault diagnosis than classical evidence theory in fusing multi-symptom domains and seems more reasonable than before using the new belief function to determine the weight.
Abstract: Dempster–Shafer evidence theory is widely used in information fusion. However, it may lead to an unreasonable result when dealing with high conflict evidence. In order to solve this problem, we put forward a new method based on the credibility of evidence. First, a novel belief entropy, Deng entropy, is applied to measure the information volume of the evidence and then the discounting coefficients of each evidence are obtained. Finally, weighted averaging the evidence in the system, the Dempster combination rule was used to realize information fusion. A weighted averaging combination role is presented for multi-sensor data fusion in fault diagnosis. It seems more reasonable than before using the new belief function to determine the weight. A numerical example is given to illustrate that the proposed rule is more effective to perform fault diagnosis than classical evidence theory in fusing multi-symptom domains.
146 citations
TL;DR: In this article, a review of the state-of-the-art analytical, computational, and experimental techniques have been developed, which greatly contribute to the exploration of turbulence and heat transfer mechanisms.
Abstract: Turbulent flow and heat transfer are key issues in nature and numerous engineering applications such as human body, fluid machinery, machining facilities, and refrigeration systems. Insight into relevant transient and steady-state thermo-fluidic physics in such scenarios acts as constructive guidance for both engineers and scientists to improve the performance and reliability of facilities, analyze engineering failures, and understand complicated natural phenomena. Unfortunately, such complex fluid flow and heat transfer problems can rarely be solved analytically due to the strong nonlinearity of the Navier–Stokes equations and the complex nature of turbulence with heat transfer. Instead, advanced modeling and measurement techniques become compensatory yet powerful tools and have been widely used. Especially in recent years, a large number of advanced analytical, computational, and experimental techniques have been developed, which greatly contribute to the exploration of turbulence and heat transfer mechanisms. The main objective of this Special Issue is to bring important information on advanced modeling and measurement techniques together. Their feasibility and performance in investigating various engineering problems are evaluated. In this Special Issue, five original research papers were accepted for publication based on critical peer review by qualified reviewers. We hope that such a frontier of turbulence and heat transfer could be continued to track the updated trend year by year. An introductory review of the accepted papers is presented here. In the paper entitled ‘‘The impact research of control modes in steam turbine control system (digital electric hydraulic) to the low frequency oscillation of grid,’’ theoretical models for frequency domain analysis were developed to investigate the effects of steam turbine control modes on low-frequency oscillation of grid. The effectiveness of such theoretical analysis was well validated by simulation using the control system’s toolbox in MATLAB. In the paper entitled ‘‘Research on the aerodynamic characteristics of a lift drag hybrid vertical axis wind turbine,’’ the effects of various parameters on unsteady aerodynamic and starting performances of a newly designed lift drag hybrid vertical axis wind turbine were numerically investigated. The performances of various turbulence models were evaluated based on experimental data. Fruitful guidance for engineering design was also obtained. In the paper entitled ‘‘Pressure fluctuation prediction in pump mode using large eddy simulation and unsteady Reynolds-averaged Navier–Stokes in a pump-turbine,’’ both large eddy simulation and unsteady Reynolds-averaged Navier– Stokes equations in conjunction with a two-equation turbulence model were adopted to predict pressure fluctuation in pump mode of a pump-turbine. By comparisons between experimental and numerical results, the performances of these two different modeling methods were evaluated. In the paper entitled ‘‘Temperature field measurement of spindle ball bearing under radial force based on fiber Bragg grating sensors,’’ fiber Bragg grating temperature sensors were proven to be an effective method in the measurement of temperature distribution in outer ring of a spindle ball bearing. Such a temperature field is physically beneficial for the reduction of spindle thermal error. Finally, in the paper entitled ‘‘Experimental investigation of flow boiling heat transfer and pressure drops characteristic of R1234ze(E), R600a, and a mixture of R1234ze(E)/R32 in a horizontal smooth tube,’’ the effects of mass flux, heat flux, and quality of several refrigerants on flow boiling and pressure drop characteristics in a horizontal smooth tube was experimentally investigated. The corresponding experimental methods and findings from this study are useful for the design of evaporators.
137 citations
TL;DR: A novel robot grasp detection system that maps a pair of RGB-D images of novel objects to best grasping pose of a robotic gripper and presents a two-stage closed-loop grasping candidate estimator to accelerate the searching efficiency of grasping-candidate generation.
Abstract: Autonomous manipulation has enabled a wide range of exciting robot tasks. However, perceiving outside environment is still a challenging problem in the field of intelligent robotic research due to ...
136 citations
TL;DR: In this paper, the effect of utilizing semi-attached rib on heat transfer and liquid turbulent flow of nanofluid water-copper oxide in three-dimensional rectangular microchannel has been investigated.
Abstract: In this research, the effect of utilizing semi-attached rib on heat transfer and liquid turbulent flow of nanofluid water–copper oxide in three-dimensional rectangular microchannel has been investigated. The results of numerical examination of this study in comparison to those of smooth channel have also been evaluated. The range of Reynolds numbers is between 10,000 and 60,000 and the volume fraction of copper oxide nanoparticle in 0%, 2%, and 4% was examined. In this numerical simulation, the effects of the changes in parameters such as dimensions of semi-attached rib, volume fraction of the nanoparticle, and Reynolds number were considered. The results of this study showed that utilizing semi-attached rib in microchannel with a ratio of 0 < R/W ≤ 0.325 in producing stronger vortices, which causes better mixture in fluid layers, is weaker than that with tooth mode of R/W = 0 ratio. However, the main advantage of using tooth with a ratio of 0 < R/W ≤ 0.325 in comparison to ordinary tooth is the increase ...
132 citations
TL;DR: In this article, the friction materials were classified by matrix categories, and their major components were introduced first, then, the advantages and disadvantages of each friction material were summarized and analyzed, and the micro-contacting behaviors on friction interface and the formation mechanism of various friction films were discussed.
Abstract: The friction brake works as an indispensable guarantee for regular work and safety operation of vehicles and industrial equipments. Friction and wear behaviors of brake’s friction materials are considered as an important subject. In this article, friction materials were classified by matrix categories, and their major components were introduced first. Then, the advantages and disadvantages of each friction material were summarized and analyzed. Furthermore, the micro-contacting behaviors on friction interface and the formation mechanism of various friction films were discussed. Finally, the influential rules and mechanism of braking conditions (temperature, pressure, and velocity) on the friction and wear behaviors of friction materials were summarized. It is concluded that the friction film, an intermediate product in braking, is greatly beneficial to protect friction materials from being seriously abraded. The braking conditions have complicated influences on friction and wear behaviors of brake. Genera...
111 citations
TL;DR: Nanofluids are solid/liquid suspensions of higher thermal conductivity and viscosity compared to common working fluids as mentioned in this paper, and their application in heat transfer enhancement is prospective. But their performance is limited.
Abstract: Application of nanofluids in heat transfer enhancement is prospective. They are solid/liquid suspensions of higher thermal conductivity and viscosity compared to common working fluids. A number of ...
TL;DR: In this paper, an acquisition system for the measurement of micro-electro discharge machining process parameters and the statistical analysis of their influence on the process performance is presented. Butt et al. used a linear and non-linear regression approach in order to obtain predictive equations for the most important aspects of micro electro discharge process, such as the machining time and the electrode wear.
Abstract: This article is about the implementation of an acquisition system for the measurement of micro-electro discharge machining process parameters and the statistical analysis of their influence on the process performance. The micro-electro discharge machining drilling of 316L stainless steel with copper tubular electrodes was studied and the exchanged power was taken into account as a comprehensive variable able to represent the effect of the peak current and voltage on the final result. The direct proportionality between the exchanged power and the nominal process parameters was verified. A linear and non-linear regression approach was used in order to obtain predictive equations for the most important aspects of micro-electro discharge machining process, such as the machining time and the electrode wear.
TL;DR: The results have experimentally proven that self-adaptive probabilistic neural networks have a more accurate prediction and better generalization performance when addressing the transformer fault diagnosis problem.
Abstract: Probabilistic neural network has successfully solved all kinds of engineering problems in various fields since it is proposed. In probabilistic neural network, Spread has great influence on its performance, and probabilistic neural network will generate bad prediction results if it is improperly selected. It is difficult to select the optimal manually. In this article, a variant of probabilistic neural network with self-adaptive strategy, called self-adaptive probabilistic neural network, is proposed. In self-adaptive probabilistic neural network, Spread can be self-adaptively adjusted and selected and then the best selected Spread is used to guide the self-adaptive probabilistic neural network train and test. In addition, two simplified strategies are incorporated into the proposed self-adaptive probabilistic neural network with the aim of further improving its performance and then two versions of simplified self-adaptive probabilistic neural network (simplified self-adaptive probabilistic neural network...
TL;DR: Failure mode and effects analysis is an important methodology, which has been extensively used to evaluate the potential failures, errors, or risks in a system, design, or process as mentioned in this paper.
Abstract: Failure mode and effects analysis is an important methodology, which has been extensively used to evaluate the potential failures, errors, or risks in a system, design, or process. The traditional ...
TL;DR: The aim of this Special Issue is to highlight the most significant recent developments on the topics of SI and to apply SI algorithms in real-life scenarios.
Abstract: Swarm intelligence (SI) is an artificial intelligence technique based on the study of cooperation behaviors of simple individuals (e.g. ant colonies, bird flocking, animal herding, and bees gathering honey) in various decentralized systems. The population, which consists of simple individuals, can usually solve complex tasks in nature by individuals interacting locally with one another and with their environment. Although a simple individual’s behavior is primarily characterized by autonomy, distributed functioning, and self-organizing capacities, local interactions among the individuals often lead to a global optimal. Therefore, SI is a promising way to develop powerful solution methods for complex optimization problems in mechanical engineering. Recently, SI algorithms have attracted much attention of researchers and have also been applied successfully to solving optimization problems in mechanical engineering. However, for large and complex problems, SI algorithms often consume too much computation time due to the stochastic features of their searching approaches. Thus, there is a potential requirement to develop efficient algorithms that are able to find solutions under limited resources, time and money in realworld applications. The aim of this Special Issue is to highlight the most significant recent developments on the topics of SI and to apply SI algorithms in real-life scenarios. Contributions containing new insights and findings in this field are welcome. Papers selected for this Special Issue present new findings and insights into this field. A broad range of topics are discussed, especially in the following areas: SI algorithms for scheduling of machinery production line, mechanical parameters adjustment based on SI, application of SI algorithms in mechanical fault diagnosis and SI and mechatronics. In the paper titled ‘‘Pareto optimal train scheduling for urban rail transit using generalized particle swarm optimization,’’ W. Chu et al. established a bi-objective optimization model to study the Pareto optimal urban rail train scheduling problem. The aim of the model was to minimize the passengers’ total travel time and the number of used train stocks at the same time. A Pareto-based particle swarm optimization procedure was designed to solve the model. Finally, two different scaled urban rail lines were applied to test the model and the algorithm. In the paper titled ‘‘Estimation of vessel collision risk index based on support vector machine,’’ L. Gang et al. proposed a collision risk index estimation model based on support vector machine and applied genetic algorithm to optimize the corresponding parameters. And the comparison between cross-validation-support vector machine, particle swarm optimization–support vector machine, and genetic algorithm–support vector machine models showed that genetic algorithm–support vector machine model generally provided a better performance for collision risk index estimation. In the paper titled ‘‘Automobile chain maintenance parts delivery problem using an improved ant colony algorithm,’’ J. Gao et al. solved the automobile chain maintenance parts delivery problem by transferring the multi-depot vehicle routing problem with time windows to multi-depot vehicle routing problem with the virtual central depot. Then an improved ant colony optimization with saving algorithms, mutation operation, and adaptive ant-weight strategy was proposed to solve the problem. And the computational results indicated that the proposed algorithm was effective to solve the problem. In the paper titled ‘‘Pareto front–based multiobjective real-time traffic signal control model for intersections using particle swarm optimization algorithm,’’ P. Jiao et al. proposed a Pareto front–based multi-objective traffic signal control model to obtain real-time signal parameters and evaluation indices. The objectives of the model were to minimize delay time, minimize number of stops, and maximize effective capacity. In addition, a step-by-step particle swarm optimization algorithm based on Pareto front was
TL;DR: In this article, the design and development capabilities, which provided products with vitality and value, had become one of the key factors in transforming and upgrading enterprises, and also, the ind...
Abstract: In recent years, the design and development capabilities, which provided products with vitality and value, had become one of the key factors in transforming and upgrading enterprises. Also, the ind...
TL;DR: The proposed computer-aided diagnosis system is effective in detecting abnormal breasts and is better than both the proposed “weighted-type fractional Fourier transform+principal component analysis+k-nearest neighbors” and other five state-of-the-art approaches in terms of sensitivity, specificity, and accuracy.
Abstract: Abnormal breast can be diagnosed using the digital mammography. Traditional manual interpretation method cannot yield high accuracy. In this study, we proposed a novel computer-aided diagnosis system for detecting abnormal breasts. Our dataset contains 200 mammogram images with size of 1024 × 1024. First, we segmented the region of interest from mammogram images. Second, the fractional Fourier transform was employed to obtain the unified time–frequency spectrum. Third, spectrum coefficients were reduced by principal component analysis. Finally, both support vector machine and k-nearest neighbors were used and compared. The proposed “weighted-type fractional Fourier transform+principal component analysis+support vector machine” achieved sensitivity of 92.22% ± 4.16%, specificity of 92.10% ± 2.75%, and accuracy of 92.16% ± 3.60%. It is better than both the proposed “weighted-type fractional Fourier transform+principal component analysis+k-nearest neighbors” and other five state-of-the-art approaches in term...
TL;DR: In this article, the residual power series method for solving nonlinear time fractional reaction diffusion equations is introduced, which gets Maclaurin expansion of the s.r.t.
Abstract: In this article, the residual power series method for solving nonlinear time fractional reaction–diffusion equations is introduced. Residual power series algorithm gets Maclaurin expansion of the s...
TL;DR: In this paper, the authors reviewed the state-of-the-art for the hybrid wheel loader and excavator, which focuses on powertrain configuration, energy storage devices, and energy management strategies.
Abstract: With the increasing attention of energy saving and emission reduction technology, the recent application of hybrid powertrain technology affects the development of construction machinery industry. This article reviews these publications and provides comprehensive references. This article reviews the state-of-art for the hybrid wheel loader and excavator, which focuses on powertrain configuration, energy storage devices, and energy management strategies. The basis of classification and characteristic of each powertrain configuration are described. Advantages and disadvantages of batteries, supercapacitors, hydraulic accumulators, and flywheel used in hybrid construction machinery are summarized. The existing energy management strategies for hybrid construction machinery are also elaborated. The technological challenges and developing trends in the near future for hybrid construction machinery are discussed.
TL;DR: In this paper, the authors argue that diesel engines are inevitable parts of our daily life and will be in the future and that expensive after-treatment technologies to fulfil normative legislations about the harmful tail-pipe emissions and fu...
Abstract: Diesel engines are inevitable parts of our daily life and will be in the future. Expensive after-treatment technologies to fulfil normative legislations about the harmful tail-pipe emissions and fu...
TL;DR: In this article, the effects of severe wear on railway vehicles and maintenance costs of tracks are explored, which strongly affects the dynamic performance of railway vehicles, as well as their maintenance costs.
Abstract: Severe wear is a common damage mechanism in railway turnouts, which strongly affects the dynamic performance of railway vehicles and maintenance costs of tracks. This article explores the effects o...
TL;DR: In this paper, the authors present a virtual real-time approach for assembly operations in modern manufacturing systems, where the assembly operations represent an important part of the cost of a product.
Abstract: Assembly operations are a key component of modern manufacturing systems. Designing, planning, and conducting assembly operations represent an important part of the cost of a product. Virtual realit...
TL;DR: In this paper, the non-differentiable solution of the linear and non-linear partial differential equations on Cantor sets is implemented in a local fractional operator sense, and four illustrative examples are given to show the efficiency and accuracy features of the presented technique.
Abstract: The non-differentiable solution of the linear and non-linear partial differential equations on Cantor sets is implemented in this article. The reduced differential transform method is considered in the local fractional operator sense. The four illustrative examples are given to show the efficiency and accuracy features of the presented technique to solve local fractional partial differential equations.
TL;DR: The research reported in this article was supported by the European Commission within the project "Minimizing Defects in Micro-Manufacturing Applications (MIDEMMA)" (FP7-2011-NMP-ICT-FoF-285614) as discussed by the authors.
Abstract: The research reported in this article was supported by the European Commission within the project ‘Minimizing Defects in Micro-Manufacturing Applications (MIDEMMA)’ (FP7-2011-NMP-ICT-FoF-285614).
TL;DR: A comprehensive survey of reconfigurable modular robots can be found in this article, which covers the origin, history, state of the art, key technologies, challenges, and applications of modular robots.
Abstract: This article presents a comprehensive survey of reconfigurable modular robots, which covers the origin, history, the state of the art, key technologies, challenges, and applications of reconfigurab...
TL;DR: In this paper, a hybrid gas-path analysis approach integrating gray relation algorithm into gaspath analysis method has been proposed in order to improve the robustness of gas turbine gaspath fault diagnosis.
Abstract: Gas-path analysis method has been widespread applied to gas turbine engine health control and has become one of the key techniques in favor of condition-oriented maintenance strategy. Theoretically, gas-path analysis method (especially nonlinear gas-path analysis) can easily quantify gas-path component degradations. However, when the number of components within engine is large which highly expands the dimension of fault coefficient matrix, maybe leading to strong smearing effect (i.e. predicted degradations are located almost in all component health parameters, although some of them are not really degraded), the degraded components may not be accurately identified. In order to improve the robustness of gas turbine gas-path fault diagnosis, a hybrid gas-path analysis approach integrating gray relation algorithm into gas-path analysis method has been proposed in this study. The gray relation algorithm and gas-path analysis method approach includes two steps. First, the faulty components are recognized and i...
TL;DR: In this article, a bidirectional shaft tubular pump was proposed for low head water conservation projects for drainage and irrigation purposes, which is a new type of low head pump.
Abstract: The low head pump is widely used in many important water conservation projects for drainage and irrigation purposes. A new type of low head pump, the bidirectional shaft tubular pump, consists of a...
TL;DR: In this article, the authors demonstrate the use of an empirical and simplified approach based on an optical technique and a home-made ad hoc code that gives knowledge of the shape and fallin...
Abstract: The work presented in this article demonstrates the use of an empirical and simplified approach based on an optical technique and a home-made ad hoc code that give knowledge of the shape and fallin...
TL;DR: In this article, the authors proposed a collision risk index for assessing vessel collision risk, which is one of the key problems in the research field of vessel collision avoidance, and obtained accurate collision risk indices.
Abstract: Collision risk index is important for assessing vessel collision risk and is one of the key problems in the research field of vessel collision avoidance. With accurate collision risk index obtained...
TL;DR: In this paper, a compression ignition engine with a mechanical fuel system was converted into a common rail fuel system by means of a self-developed electronic control unit, and the engine was modified to be operated by a locomotive.
Abstract: A compression ignition engine with a mechanical fuel system was converted into common rail fuel system by means of a self-developed electronic control unit. The engine was modified to be operated w...