bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimization Method Research for Stiffened Thin Wall Structure’s Vibration Suppression Based on Parametric Modeling Technique
Authors: Jin Wei , Mou Bin Jie , Huang Hu , Fu Huan Bing
Published: October 2015

Stiffened Thin Wall Panel Structure is a widely used structural configuration in the design of aircraft’s inlet duct and large open bay. Vibration fatigue failure of stiffened panel structure will quickly emerges under strong broadband random loading environment which caused by shock waves moving at the inlet lip and cavity vortex and shear layer oscillation during flight. At present, a main research focus on dynamic strength design of aircraft’s light-weight structure is to reduce the dynamic stress response level in broadband random vibration environment ,so as to improve the ability of thin wall panel’s vibration fatigue property with light structure weight. Taking a stiffened thin panel of inlet duct as a typical case under random vibration excitation environment, an Advanced dynamical topology optimization methods is established based on the parametric modeling technique . Within the main frequency domain of external dynamic load, the maximum root mean square of stress (MRMSS) for global element of stiffened panel structure is calculated and optimized under the weight constraint with Genetic Optimization Algorithm (GOA). The comparison of structural stress response before and after optimization design shows that the maximum element RMS dynamic stress is reduced by 38% with the weight increased by about 9.8% and the purpose of improving vibration fatigue property is reached.
Noise and Vibration Measurements for the Assessment of Damping Efficiency in Power Transformers
Authors: Kmita Grzegorz , Kozupa Michał , Bustreo Gianluca , Hrkac Miljenko , Zannol Roberto , Kolber Karolina
Published: October 2015

Power transformers emit a very characteristic harmonic sound during operation. The sound spectrum consists of the harmonics of double frequency of the power grid with the fundamental of 100Hz or 120Hz in different countries around the world. This fundamental frequency dominates in the sound spectrum during the load condition while the higher harmonics are representative for the no-load operating state. Regardless of loading conditions, all the harmonics build rather unpleasant noise, which is difficult to suppress. Moreover, this noise is sometimes difficult to measure and interpret, due to the harmonic nature and a content of harmonics of relatively low frequencies.This paper presents the exemplary study on the assessment of noise damping efficiency, performed with the use of laser vibrometry and sound intensity measurements, which can provide the most complete information, when it comes to the identification of the sources of noise as well as to the proper evaluation of damping solutions.
An Investigation of Internal Viscous Damping Effects on the Vibration of a Microbeam Made of Functionally Graded Materials
Authors: Maleki Erfan , Sherafatnia Khalil , Pasharavesh Abdoreza , Zabihollah Abolghasem
Published: October 2015

In this paper, effect of the internal viscous damping on the frequency shift and damping ratios of a microbeam made of functionally graded materials is investigated for different boundary conditions. To achieve this goal the FGM microbeam is modeled by an Euler-Bernoulli beam and utilizing Hamilton principle the governing partial differential equation of motion and corresponding boundary conditions are obtained. Applying mode summation method, the governing ordinary differential Eq. is derived from the PDE. Solving the ODE analytically, frequency shift ratio of the FGM microbeam is evaluated for different boundary conditions. Results are presented in terms of material damping coefficient. The effects of design parameters such as boundary conditions, geometrical parameters, distribution function and viscous damping coefficient on the frequency shift and damping ratios are assessed.
Modal Analysis as the Base of Dynamic Analysis
Authors: Monkova Katarina , Monka Peter , Cizikova Andrea , Murgas Filip , Rehor Jan , Edl Milan
Published: October 2015

The article deals with the modal analysis as a tool for specification of natural frequencies and the mode shapes of the turning tool. This type of analysis is the first step that is necessary to do at the dynamic analysis of technical components. At the beginning, the verification of numerical method was realized in laboratory conditions, where the fixed beam substituted the turning tool. Vibrodiagnostics of the real cutting tool in the workshop and the modal analysis using FEM in the software PTC Creo followed. It can be said that the results of the numerical method based on FEM were comparable with the data achieved by means of experimental measurements. The work described in this paper can be considered as a foundation for the dynamic tool life analysis.
Evaluation and Improvement of Performance Parameters for a Mechanical System Used in Minirobotics
Authors: Dumitru Violeta , Dumitru Sorin
Published: October 2015

The concept, design and construction of mechanical systems performance is limited by the ranges prescribed for different performance parameters (size, accuracy, repeatability, quality, safety, and cost). The aim of the research is to evaluate and improve the performance parameters for a mechanical system with multiple vertebrae drive by wire, to perform functions of exploration, inspection and intervention in limited space environments (anatomical). New mechanical structure contains modules that allow changing the work parameter and the algorithms to control the location (position, orientation) of the end effector. Sensory system can be configured depending on the product and the program chosen, embracing suitable position, bending and strength sensors. Error compensation by a feedback process has become the most economical solution and easier to apply. Rigidity functions and bending forces resolution are presented along with a simulation of robotic arm positions for all vertebrae. The results demonstrate the capability of this system to perform precise movements to an imposed target.
Experimental Study of Defluidization by Continuous Water Injection into a Gas-Solid Fluidized Bed Using Pressure Fluctuation Measurements
Authors: Tramontin Silveira Schaffka Flavia , Tramontin Giulia Kaminski , Parise Maria Regina
Published: October 2015

This work studies the induced defluidization condition of a gas-solid fluidized bed system when distilled water is continuously injected into the bed of particles. Experimental tests carried out to different water flow rates were analyzed through a technique based on pressure signals measurements. The bed material used was glass beads (Geldart D particles), with mean diameter of 1.55 mm. Experiments were performed in an acrylic Plexiglas tube with 0.11m in inner diameter and 1.0 m in height, with the bed led from an initially bubbling regime up to attain a fixed bed condition. Pressure fluctuations were acquired and processed using LabVIEW 10.0TMsoftware. Results showed that the defluidization condition promoted by water injection in a bubbling fluidized bed can be efficiently identified using pressure fluctuation measurements.
Ethanol Lean Combustion Characteristics of a GDI Engine
Authors: Costa Roberto B.R. , Gomes Carlos A.J. , Pujatti Fabricio J.P. , Valle Ramon Molina , Barros José E.M.
Published: October 2015

In the present study, ethanol combustion analysis was carried in a wall guided type GDI engine, to achieve combustion stability under lean burn operation and to expand the flammability limit for increasing engine efficiency. Tests were performed at constant engine speed, load and injection pressure (1000 rpm, NIMEP = 3 bar, 100 bar), for a wide range of injection, ignition and mixture formation parameters. NISFC, combustion stability, PMEP and burn duration were evaluated at each excess air ratio. An improvement on fuel economy and, consequently, increased engine efficiency was achieved for excess air ratios of λ = 1.1 and λ = 1.2.
Numerical Analysis of a Torch-Ignition System for an Internal Combustion Engine
Authors: Radicchi Fábio , Braga Raphael M. , Coelho Raniro A. , Costa Roberto B.R. , Valle Ramon Molina
Published: October 2015

Torch ignition systems in spark-ignition engines represents an interesting option in the efforts to reduce pollutants emission and specific fuel consumption. Based on this idea, this paper presents a 3D model of a prechamber created for a spark-ignition engine and focuses on the numerical analysis of the fluid flow inside the modified chamber. This kind of analysis is very important once it allowed evaluating aspects like turbulence parameters, pressure inside the chamber and prechamber, fluid recirculation and a possible prechamber’s geometry for the engine. The studies were done in a four valve Single Cylinder Research Engine – SCRE. For the numerical modeling and fluid flow investigation was used STAR-CD software. Results show higher values of tumble ratio and kinetic energy with the prechamber.
Flanged Connections of Steel Tubular Sections under High Bending Stresses: A Comparison between Two Thickness Design Methods
Authors: Velten A.M. , Pinto R.L.U. de F.
Published: October 2015

This work presents a comparison of different possibilities of flange design of an aeolian tower structure, focusing the thickness determination, the critical connection parameter. The dimensioned structure is a fifteen-meter length tubular arm under bend stresses caused by wind loads and by gravitational loads, since the tubular arm might be horizontal or vertically positioned. The tubular sections connected by the flanges are all circular with external diameter varying from 270 to 360 mm and the flange modules are also circular shaped. Since the tubular diameters are relatively large, the lever effect plays a definitive role in the design. Most of the fluid conduits flange design criteria are not applicable for such diameters sizes and have a load case different from those of an aeolian tower. Two different approaches are presented and their flange thickness results compared.
Formation Control of Quadrotor UAVs by Vision-Based Positioning
Authors: Kim Wooh Yun , Kwon Ji Wook , Seo Ji Won
Published: October 2015

In this paper, a formation control method of quadrotor Unmanned Aerial Vehicles (UAVs) by vision-based positioning is presented. The relative positions and attitudes of two UAVs with respect to a visual marker attached to the third UAV is estimated by a camera calibration method. Based on the estimated positions and attitudes, two UAVs are controlled to the desired positions to form a given formation with respect to the third UAV. A simplified dynamics model of a quadrotor UAV is utilized to design a controller. The proposed formation control method is validated by an experiment with a motion capture system which provides the ground truth of the position data.
Mapping by Optimization of the Minimum Volumetric Error in Coordinate Measuring Machines
Authors: di Giacomo Benedito , de Morais César Augusto Galvão
Published: October 2015

The CMM (coordinate measuring machines) are able to perform dimensional inspections in workpieces with complex geometries, in a short time compared to conventional methods, however, errors on volume of CMM harm the performance of measurement. Faced with this, the purpose this investigation is to identify regions in the machine with large and small values of volumetric errors. The mapping of volumetric error is performed by optimization of objective function with SQP method. The objective function is defined by modeling errors of the CMM using a method of the homogeneous transformation, and, by calibration curves of individual errors. The optimization allowed to obtain the smallest value of volumetric error, 1.1796 μm, located near the linear encoder of the y axis. The mapping the volumetric error by optimization allows to know regions with minor harm the performance of measurement, therefore, it's possible to select regions of measurement to obtain reliable results.
Teaching Industrial Robot Manipulators by Easy to Use Interface Systems
Authors: Capi Genci , Hossain Delowar , Kaneko Shi Ichiro , Bode Koco
Published: October 2015

The need for simple and safe teaching methods for robot manipulators need to be considered because: 1) Small size robots presence in everyday life environments is increasing requiring non-experts operators to teach the robot; 2) In small applications, the operator has to teach several different motions in a short time. In this paper, we evaluate the performance of three teaching systems for robot manipulators which utilize the following devices 1) i-phone; 2) haptic and 3) kinect. In difference from previous force sensor based teaching, proposed systems are safe because the operator keeps the distance with the robot. The performance is compared in terms of time to complete the task and accuracy. The results of 10 non-experienced subjects show the advantages of one method over the others.
Design of Passive Weight Compensation for a Robotic Manipulator
Authors: Uriza Pablo Andrés , Rodriguez Carlos F.
Published: October 2015

A serial link manipulator consist of various unbalanced bars (links) attached by torsional joints that are subjected to torque loads due to the weight and configuration of the manipulator. This paper proposes a solution to passive weight compensation for serial link manipulators, using torsional springs. A set of characteristic points is selected and evaluated through sensibility analysis to define the required maneuvers. A nonlinear optimization methodology is used to find the springs parameters to minimize the energy consumption during the execution of the defined maneuvers. The energy saving is estimated through simulation as well as the effect of the maximum preload allowed for the spring.
In  Situ X-Ray Diffraction Measurements of the Apparent Modulus of Human Dental Tissue in the Vicinity of the Dentine-Enamel Junction (DEJ)
Authors: Sui Tan , Ying Si  Qi , Baimpas Nikolaos , Landini Gabriel , Korsunsky Alexander M.
Published: October 2015

The dentine-enamel junction (DEJ) is an important biological interface between the highly mineralized hard out layer (enamel) and the comparatively softer tooth core (dentine) of teeth. The remarkable performance of this interface provides the motivation for investigation into the detailed structure and function of the DEJ. In this study, synchrotron X-ray diffraction measurements of the DEJ subjected to the in situ uniaxial loading were carried out to capture the structure-property relationship between the DEJ architecture and its response to the applied force. The knowledge of the architecture and properties of the natural DEJ will hopefully help in biomimetic engineering of superior dental restorations and prostheses, and the development of novel materials to emulate the DEJ.
A FEM Frontal Impact Study of Square-Section Tubes with Different Structural Solutions for Vehicle Safety
Authors: Maia Ciro Faria , Lima Guilherme Silame Maranhão , Amorim Felipe Grossi L. , Vera Evandro Queiroz Nunes , Pasqual Alexander Matioli
Published: October 2015

The present paper presents a study of square-section tubes conditioned to a FE dynamic frontal impact analysis, considering a 10.0 m/s initial velocity against an infinitely rigid plane. A 50.0 kg punctual mass is positioned on center of the cross-sections, on the farthest side from the rigid plane and the deceleration pulse is measured along the simulations. After validating the numerical model with analytical solutions, the results are compared for four geometries with little structural differences in order to access the role of each difference on the geometry under crash situations. The results show that adding many triggers to the geometry may not be the best performance solution for crash boxes, since the geometry with few triggers achieved better values of deceleration peak than the others. In addition, the presence of holes showed to be an instability cause to the system. The structural solutions presented could be of great value for future vehicle crash box developments.
Multi-Cycle Nanoindentation Studies on TiN/TiAlN Nano-Multilayer Coating: Effects of Mechanical Properties and Coating Structure
Authors: Khlifi Kaouthar , Dhifelaoui Hafedh , Zoghlami Lassaad , Ben Cheikh Larbi Ahmed
Published: October 2015

TiAlN/TiN nanomultilayer coating was deposited on 100C6 steel (AISI 52100) substrate with the PVD technique using magnetron sputtering. Morphological examination showed the presence of domes and craters which are uniformly distributed over the entire surface.Microstructural observations revealed a columnar structure. Mechanical properties, plastic and elastic deformation resistance of TiAlN/TiN multilayer coating were studied using conventional indentation method. Multi-cycle nanoindentation technique, with variation of loading rate, was used to analyze the failure modes and mechanical behavior of TiN/TiAlN 200 cycles were performed and when the loading rate was increased from 200mN/mn to 600mN/mn, the mechanical proprieties were decreased.
Environmental Effects on the Static and Fatigue Behaviours of Hemp Fibre under Tensile Loading
Authors: Ngo Anh Dung , Ho Thu Nga , Sefrioui Manar Khalid
Published: October 2015

Environmental and loading mode effects on the tensile properties of Hemp fibre were investigated. At first, absorption of moisture into the fibre from ambient air and absorption of water into the fibre in immersion were studied. Then static and cyclic loadings tensile tests were conducted in various temperature and humidity conditions. It was found that, in ambient air (0% < RH < 80%) the moisture content of the studied fibre decreased with the increase of temperature conformed to the GAB model suggesting a multilayer absorption mechanism. On the contrary, for the fibre immersed in water, the moisture content increased with the increase of temperature. The activation of temperature on the diffusion of the water into the fibre by micro-pores and lumens jointly with the lack of possibility for the imprisoned water to evaporate might be the cause of this effect. Experimental results suggested that temperature and humidity could individually reduce the mechanical properties of Hemp fibre. Their interaction caused even a more harmful effect. Semi empirical and neural networks were used to predict the hygro-thermal effects on the mechanical properties under static tensile loading. Broken surfaces of the specimens were also examined showing different failure modes for static and cyclic tensile loadings. Finally, the value of the cellulose micro-fibrils angle (MFA) estimated using the static tensile stress-strain curve was 8.4o±1.9o.
Predicting Mechanical and Thermal Behavior of Multiphase Composite Containing Phase Change Material (PCM) by Micromechanical Approaches
Authors: Barboura Salma , Meddour Jugurtha , Haboussi Mohammed , Kachi Mouhand Said , Royon Laurent
Published: October 2015

This work is devoted to the study of thermal and mechanical properties (stiffness and thermal conductivity tensors) of multiphase composite materials (mortar with PCMs). A micro-macro modeling is presented in order to predict these properties by using some classical homogenization schemes. The effective thermo-mechanical behavior is then analyzed by considering various PCM particle forms, concentrations, and orientations.
Comparative Study of Effect of Cryogenics Heat Treatment and Case Hardening on the Wear Property of 20MnCr5
Authors: Ambekar S.D. , Kadam Sandeep , Sonawane S.A.
Published: October 2015

This research is limited to study of wear resistance of 20MnCr5 (SAE 5120) alloy steel hardened by Carburizing and Cryogenics, which has wide application in industries like gears, shafts, bearings, pins etc. Cryogenics is used as a supplement treatment that is performed after carburizing. The abrasive wear study is performed on pin-on-disc tribotester. The counterface disc was kept same for both the heat treatments (carburizing and cryogenics). Sliding velocity of 0.8 m/s, 1.6 m/s, 2.4 m/s, Sliding Distance of 1200 m, 1400 m, 1600 m and Load of 3 kg, 4 kg and 5 kg were used to evaluate the wear resistance.
Intellectualization of Surface Layers, Working under Cyclic Loading and Reversing Friction
Authors: Blednova Zhesfina Michailovna , Rusinov Peter Olegovich
Published: October 2015

The object of study is a multi-layer composition «steel – a material with shape memory effect (SME) – wear-resistant layer» (TiNiHf - WC-Mo-Co). Ni was deposited as an adhesion layer. The sequence of functional layers deposition, their composition, thickness, structural-phase state and dispersion are determined by the operating conditions and operated by processing modes. To enhance durability and longevity it is recommended to form a layer with shape memory effect in a way that its temperature, given the increase in friction, corresponded to martensitic state and had an increased relaxation and damping capacity to inhibit cracking.
FE Study of the Chips Morphology when Drilling Process
Authors: Glaa Nawel , Mehdi Kamel , Jaber Moez Ben
Published: October 2015

The finite element modeling allows manufacturers to reduce the cost of machining operations. During a drilling operation, the chips morphology their sizes and thicknesses have a great effect on the process, whatever the material to be machined. One approach to a 3D simulation of a drilling process with the finite element program Abaqus/Explicit is displayed. We studied the morphology of chips during the drilling process, the influence of cutting parameters on their shape, size and clear velocity. This study allows us to optimize the conditions and cutting parameters for a smooth process.
Analysis of Wood Biomass in Bubbling Fluidized Bed Reactors
Authors: Campos Julio Cesar Costa , Leiroz Albino J.K. , Resende Maysa T.
Published: October 2015

This article analysis the computational simulation of wood's gasification in a bubbling fluidized bed reactor. Most articles about this topic, on homogenous reactions, don’t consider methane reforming. However, this article has taken this into consideration in the process of gasification. The bubbling fluidized bed reactor was used in the simulation, in which the advantages of a good mixture is presented, one which provides high rates of mass and heat transfer. The gas-solid flow that occurs in this reactor was described through mass, energy, momentum, and chemical species balances. The model used for the simulation was the computational fluid dynamics (CFD), by means of an open-source program named MFIX (Multiphase Flow with Interphase eXchange). It is concluded that methane reforming is important in the process of gasification.
Passive Safety Analysis for the Commercial Vehicle Cab after Weight-Reduction Design
Authors: Chen Jing , Wang Hong Yin , Wang Qian , Tao Xiong Long
Published: October 2015

Lighter weight commercial vehicles facilitate faster transport, higher mobility and fuel conservation. Weight reduction and safety are mutually competing objectives. And the safety should not be compromised after weight reduction. Full size crash tests are expensive and time consuming to organize. Using a numerical simulation for predicting crash to the occupants’ safety can minimize the number of such trials. In this paper three virtual crash simulations for the three load cases: Front impact test, Roof strength test and Rear wall strength test are performed according to the European regulation ECE-R29. The explicit finite element program LS-DYNA is used for that purpose. The comparisons between simulation results and test data available in the literature are also presented in this paper.
Toolholder Internally Cooled by a Phase Change Fluid in Turning of SAE XEV-F
Authors: Roberto Ingraci Neto Rubens , Luis Fragelli Renan , Alves Fiocchi Arthur , Luis Scalon Vicente , de Angelo Sanchez Luiz Eduardo
Published: October 2015

An internal cooling system inside a toolholder was developed aiming to eliminate the need of using cutting fluid without compromising machining efficiency. A phase change coolant (R141-b), with boiling point of 32oC around 101.3 kPa (atmosphere pressure), was used to improve heat dissipation in the cutting tool. Turning tests on SAE XEV-F were carried out using coated cemented carbide inserts. The results showed that the cutting tools lives were greater with internally cooled method than in dry cutting conditions. Nevertheless, the results were limited due to the low thermal conductivity of the steel (14.5 W.m/K) that is similar to Inconel®, its abrasivity, and absence of lubricant effect of the internal cooling method. On the other hand, the cutting tool geometry was not modified as was done in others solutions found in literature and the cooling system operated in a closed loop. It has a great possibility of use by the industry because is an environmentally friendly technology.
Numerical Analysis of the Trajectory of a Basketball Considering Lift and Drag
Authors: Nikhilesh T.R , Kulkarni Prahlad
Published: October 2015

Basketball players are taught to release the ball with a backward spin. This causes a lift due to the Magnus effect. Added to this there is a drag on the ball which always acts opposite to the direction of motion. In this paper, the trajectory of a basketball considering the lift and drag is calculated using numerical methods and also the force required to shoot the ball with different initial conditions from a distance of 25 feet away from a basket which is at a height of 10 feet is analyzed. A differential equation of motion of the ball in air is framed which accounts for all the forces on the ball. It is solved by discretizing the equation and solved using a C++ code. The trajectory of the balls with different initial conditions is plotted and it is found that as the spin on the ball increases, the effort required to shoot decreases.
Third Order ENO Scheme on Non-Uniform Grid for Supersonic Flows II
Authors: Moisseyeva Yekaterina , Naimanova Altynshash , Beketaeva Asel
Published: October 2015

In the present paper we extend our earlier work on the finite-difference shock-capturing essentially non-oscillatory (ENO) scheme for a non-uniform grid. The design of the ENO scheme is based on the methodology for uniform grids. We provide the analysis of the different variations of the limiter functions for the developed algorithm to define the optimal function producing the smallest spread of the solution. The effect of the limiter choice on the mixing layer dynamics was studied for the non-uniform grid. The numerical experiments revealed that the nonoptimal choice of limiter can result in the overgrowth of the mixing layer, that is important for the numerical modeling of the combustion.
Unsteady Aerodynamic Characteristics of the Pitched Supersonic Biplane
Authors: Zhao Cheng Xi , Hua Ru Hao , Ye Zheng Yin , Jiang Yue Wen
Published: October 2015

In this work, supersonic biplanes of the Busemann concept have been analysed, focusing on the unsteady aerodynamic characteristic due to flow disturbance using Computational Fluid Dynamics (CFD) codes in viscous flow. Flow disturbance is modelled by sinusoidal pitch motion simulated by mesh morphing using radial basis functions (RBF) method. The results suggest that there are two flow patterns of the Busemann biplane: oblique wave sequences flow (Pattern A) and choke-flow (Pattern B) with higher wave drag. Unsteady aerodynamic disturbance represented by pitch motion may cause flow pattern transformation. We have also obtained that Pattern B is more stable than Pattern A and choke-flow cannot be eliminated even after returning to the initial flight attitude. Moreover, amplitudes and frequencies of sinusoidal pitch motion play important roles in flow pattern transformation and there exist critical amplitudes and frequencies.
Simulating Torsional Slip in V-Band Clamp Joints
Authors: Sahboun Salahaddin M. , Barrans Simon M.
Published: October 2015

In this paper a finite element technique to predict the torsional load capacity of V-band clamp joints is presented. The development of this complex, multi-step analysis is explained and the results compared with alternate theories which ignore or take account of transverse friction in the band to flange contact region. It is shown that accounting for transverse friction yields a better comparison with the finite element results for lower coefficients of friction whilst ignoring this component gives better results for higher coefficients of friction. Torsional load capacity is shown to increase with band diameter and T-bolt tension but to be less dependent on the coefficient of friction.
Numerical Study of the Particle Dispersion on a Supersonic Shear Layer
Authors: Makasheva Altyn , Naimanova Altynshash , Belyayev Yerzhan
Published: October 2015

The numerical study of the two-dimensional supersonic hydrogen-air mixing in the free shear layer is performed. The system of the Favre-Averaged Navier-Stokes equations for multispecies flow is solved using the ENO scheme of the third order accuracy. The k-ε two-equation turbulence models with compressibility correction are applied to calculate the eddy viscosity coefficient. The dispersion of the particles is studied by following their trajectories in the shear layer by Euler method. In order to produce the roll-up and pairing vortex rings, an unsteady boundary condition is applied at the inlet plane. At the outflow, the non-reflecting boundary condition is taken. The influence of different Mach numbers on the formation of vorticity structures and shear layer growth rate are studied. The obtained results are compared with the available experimental data and the numerical results of other authors. The numerical simulation of the particle dispersion in the shear layer with large scale vortical structure is conducted.
A Modified Discriminance in Performance Reliability Simulation of Solid Rocket Motor
Authors: Xu Hao , Bao Fu Ting , Cheng Chen , Wang Bin Hang
Published: October 2015

In the assessment of internal ballistic performance reliability of Solid Rocket Motor (SRM), eigenvalue discriminance method has long been used. In order to avoid the limitations of the traditional methods, a curve similarity discriminance modification combined with Hausdorff Distance was introduced. A Monte-Carlo simulation model of internal ballistic performance was established, and several uncertain parameters were chosen. A sample analysis of performance reliability of a designed SRM was presented. The result was credible, which proved the modification is feasible and it can meet the needs of the assessment of the internal ballistic performance reliability.
A Simple and Robust Subsonic Boundary Layer Method to Be Used with the Panel Method for Wing Calculations Using a Wing Strip Approach
Authors: Reis R.F. Francisco , Santana Guilherme A. , Iscold Paulo , Cimini Carlos A.
Published: October 2015

This paper will present the development of a simple subsonic boundary layer method suitable to be used coupled with panel methods in order to estimate the aerodynamic characteristics, including viscous drag and maximum lift coefficient, of 3D wings. The proposed method does not require viscous-inviscid iterations and is based on classical integral bi-dimensional boundary layer theory using Thwaites and Head ́s models with bi-dimensional empirical corrections applied to each wing strip being therefor robust and efficient to be used in the early conceptual stage of aircraft design. Presented results are compared to the Modified CS Method in an IBL scheme and experimental data and are shown to provide good results.
Inverse Design Method for a Supersonic Ring Wing Based on the Busemann Concept
Authors: Zhao Cheng Xi , Chen Zi Hang , Ye Zheng Yin
Published: October 2015

In this work, three new types of supersonic ring wings have been developed when cruising at a given angle. The first one is designed by a new variable-section approach based on the Licher concept with the consideration of three dimensional flow effects. The other two are designed by an inverse optimization method, which can modify the discrepancies between the CFD (Computational Fluid Dynamics) results and the linearized theory. A new stair target pressure distribution, as the key of the inverse design method, is developed to overcome drawbacks of the original one by some aerodynamic force analyses. The new ring wings have better aerodynamic performance than the initial one with the largest increment of drag-lift ratio (57.5%) and sustain the advantages at a series angles of attack.
A Contact Nonlinear Thermo-Structure Fully-Coupled Simulation for Nozzle Based on One-Time Adhesive Failure
Authors: Sun Lin , Bao Fu Ting , Zhang Ning , Xu Hao
Published: October 2015

To simulate a fully-coupled thermo-structure of a nozzle with adhesive failure, a flow field result is obtained based on a grid-independent check. The heat transfer coefficient along the nozzle is gained by Bartz formulation as an initial condition for thermo-structure simulation. A check for interface failure based on the adhesive, GD414, property is done to investigate the failure behavior, also to gain a simplified interface treatment. The gaps are chosen by experience. Then the simulation is carried out. The results show that gaps can release the stress of the interfaces while it can’t affect the whole stress distribution too much. The method is suggested to be used in the future and a more reasonable method is suggested.
Design of Walking Mechanism for All-Terrain Mobile Platform
Authors: Zhou Fa Liang , Xu Xiao Jun , Pan Cun Yun , Xu Hai Jun
Published: October 2015

The new all-terrain mobile platform can improve the human mobility in non-structure environment, which is mainly determined by the walking mechanism quality. In this paper, the walking mechanism structure is designed, and its working principle is analyzed. Theoretical analysis and parameter optimization are completed during the parameter design of the tracked circle, which verifies the parameter rationality of the self-tension mechanism. Besides, the dynamic analysis of the multi-degree of freedom suspension system is accomplished. The results show that the structure and parameter design of the walking mechanism is available, which provides theoretical basis for the new mobile platform parametric design.
Assessment of a FEM-Based Formulation for Horizontal Axis Wind Turbine Rotors Aeroelasticity
Authors: Calabretta Angelo , Testa Claudio , Greco Luca , Gennaretti Massimo
Published: October 2015

This paper presents an aeroelastic formulation based on the Finite Element Method (FEM) for performance and stability predictions of isolated horizontal axis wind turbines. Hamilton’s principle is applied to derive the equations of blade aeroelasticity, by coupling a nonlinear beam model with Beddoes-Leishman sectional unsteady aerodynamics. A devoted fifteen-degrees-of-freedom finite element to model kinematics and elastic behaviour of rotating blades is introduced. Spatial discretization of the aeroelastic equations is carried-out to derive a set of coupled nonlinear ordinary differential equations solved by a time-marching algorithm. The proposed formulation may be enhanced to face the analysis of advanced-shape blades, as well as the inclusion of the presence of the tower, and represents the first step of an ongoing activity on wind energy based on a FEM approach; as a consequence, results have to be considered as preliminary. Due to similarities between wind turbine and helicopter rotor blades aeroelasticity, validation results firstly concern with the aeroelastic response of helicopter rotors in hovering. Next, the performance of a wind turbine in terms of blade elastic response and delivered thrust and power is predicted and compared to that provided by a validated aeroelastic solver based on a modal approach as well as with experimental data.
A New Design Concept for Wind Turbine Airfoil
Authors: Ye Kun , Ye Zheng Yin , Qu Zhan
Published: October 2015

Wind energy has been attracting more and more attentions due to its clean and renewable source. The aerodynamic characteristic of wind turbine airfoil directly affects the turbine efficiency. In order to improve the airfoil aerodynamic characteristic, a new concept airfoil configuration for wind turbine is presented. A cave on the upper surface near the trailing edge is designed to generate a trapped vortex in the cave. The trapped vortex is used to stabilize the separated flow when the airfoil at high angle of attack. Combining with the Gurney flap, the airfoil with the cave behaves very good aerodynamic characteristics at wide range of incidences, especially at high angles of attack. The method is used on the well-known FFA-W3-301 turbine airfoil. By using numerical simulation, it is shown that the new airfoil has a higher lift than the original airfoil at the same angle of attack, the stall angle of attack increases from 12 degree to 17 degree, and the maximum lift coefficient increases approximately 64 percents. In addition, the effects of the chord-wise location of starting point of the designed cave are discussed. Therefore, it is believed that the new-designed concept can be investigated and explored further for wind turbine.
Energy Analysis of Ethanol Steam Reforming Integrated Solid Oxide Fuel Cell for Electrical Power Generation
Authors: Srisiriwat Nawadee
Published: October 2015

As Thailand is importantly an agricultural country driving the bio-ethanol production from agricultural feedstock via fermentation process and a solid oxide fuel cell (SOFC) has been known as an attractive energy conversion device due to its high efficiency and fuel flexibility, SOFC fueled by ethanol for electrical power generation has been performed. Hydrogen-rich gas from ethanol steam reforming is used as fuel carrier converting to generate electrical energy in SOFC. This paper presents an energy analysis of integrated steam reformer and SOFC system to determine the suitable ethanol concentration giving the optimum SOFC electrical efficiency. In this study, the ethanol concentrations between 20 and 56 %wt corresponding to water-to-ethanol ratios from 10 to 2 were varied at a fixed feed flow rate of 1 g/s of ethanol solution for hydrogen production. The SOFC power efficiency increased although the amount of hydrogen and SOFC electrical power decreased with decreasing the ethanol concentration. However, for the first law analysis, the heat load of each unit was calculated and it can be concluded that the overall system efficiency increased with increasing the ethanol concentration.
Design a Transformable Wheel for Enhancing Mobility of 4-Wheeled Mobile Robot
Authors: Kim In Ho , Park Jung Wan , Lee Jae Seong , Jeong Woo Young , Yang Hyun Seok
Published: October 2015

This paper proposes a design of transformable wheel for enhancing mobility. Mobility evaluation is performed by mechanical theories as stability margin and obstacle overcoming and its calculating methods are used for simulations. A feasibility of suggested transformable wheel is investigated by simulations. The mobility is able to verify by stability margin angle and ability of climbing up an obstacles which is higher than radius of wheel. Simulation results show that suggested transformable wheel can help overcoming a mobility limitation of former designed robot which is with non-transformable wheel.
Design a New Worm-Type Mechanism of Mobile Robot Applicable in Colonoscopy
Authors: Park Jae Hyun , Kim In Ho , Cho Woong Hee , Park Jung Wan , Yang Hyun Seok
Published: October 2015

This paper presents a new mechanical design of mobile robot which can travel in the condition of continuous varying environment, such as colon of human body. Especially, the human colon environment contains an intense diameter change. The suggested mechanical design is capable to adapt in wide diameter changing system by generating two basic motions, rotational and linear motion, with a single actuator. Prototypes is fabricated, and tested result is presented in this paper. Also, experimental result is compared with the mathematical model of the mechanism to verify the feasibility of the proposed mechanism.
Equilibrium Control on Four-Limbed Climbing Robot
Authors: Nguyen Anh Dung , Shimada Akira
Published: October 2015

This research represents a method to improve the technology that enables the design andsimulation of a four-limbed climbing robot, named FLC-Robot. It is equipped with planning capabilitiesto free climb vertical terrain. It means to extend the robot's ability to a vertical direction underthe gravity force. However, we need to analyze climbing and create the theory in parallel with hardwaredevelopment. In this paper, the equilibrium allowance area of the four-limbed climbing robotis introduced and the corresponding torque is calculated. Hence, this paper starts with a rudimentaryanalysis of mechanical structure and kinematics of FLC-robot. Secondly, a 3D climbing robot modelis built and simulated in Matlab-Simscape environment. Finally, the corresponding motion planningand control method is performed considering statics and dynamics.This research represents a method to improve the technology that enables the design andsimulation of a four-limbed climbing robot, named FLC-Robot. It is equipped with planning capabilitiesto free climb vertical terrain. It means to extend the robot's ability to a vertical direction underthe gravity force. However, we need to analyze climbing and create the theory in parallel with hardwaredevelopment. In this paper, the equilibrium allowance area of the four-limbed climbing robotis introduced and the corresponding torque is calculated. Hence, this paper starts with a rudimentaryanalysis of mechanical structure and kinematics of FLC-robot. Secondly, a 3D climbing robot modelis built and simulated in Matlab-Simscape environment. Finally, the corresponding motion planningand control method is performed considering statics and dynamics.
Development of Indirect Adaptive Control for Underwater Vehicles Using Nonlinear Estimator of Disturbances
Authors: Pshikhopov Viacheslav , Medvedev Mikhail , Gurenko Boris
Published: October 2015

In this paper, authors propose a new method of disturbance estimation that can be used for marine and air vehicles. As stability area for nonlinear systems is connected with performance of estimation, indirect measurement is proposed to estimate the error. The base for calculation is vehicle accelerations provided by navigation system. New algorithms were tested in simulation for which authors developed a block diagram of indirect adaptive control system that features independence of estimator from controller. Analysis of results showed that the error of the developed estimator in transient mode is 30-40% less than error of the linear estimator. In steady state mode, gain of the proposed estimator is equal to gain of the linear estimator and output noise is the same. Simulated system was implemented in mini motor boat, and showed good results in experiment. New estimator allowed to increase the accuracy of moving along the paths.
Reliability Analysis for Parallel-Serial Robots in Automotive Assembly Plant: A Case Study
Authors: Fudzin Ahmad Fauzi , Abd Majid Mohd Amin
Published: October 2015

Robot arrangement in the automotive assembly plant in manufacturing environment consists of series and parallel configurations. Robot subsystems at painting lines were configured in series configuration while overall system was configured in parallel. Interruption of operations due to breakdown at both subsystems during operation would affect the production throughput. The robots’ breakdown data for each subsystem were acquired for reliability analysis of parallel-serial configuration of robots. This study is to analyze the serial subsystems robot reliability compared to reliability of robots in overall system in parallel-serial configuration. The seven years actual breakdown data were acquired from the automotive painting plant. By using the reliability block diagram (RBD) method, at the 5000 operating hours, the two subsystems at the painting lines were evaluated. Reliability of the two subsystems are 0.029 and 0.119 respectively. While the overall parallel-serial system has the reliability of 0.145. It is proven that the parallel-serial reliability of the system is better compared to series configuration of the subsystems. With parallel-serial system, the production line would not be interrupted during the corrective or preventive maintenance worked.
Energy Minimization of Humanoid Robot through Combining Dynamic Power Management Method with Real-Time Scheduling Method
Authors: Luo Lu Ping , Yuan Chao , Xue Gang , Yang Mei Zhi , Zhang Xue Wei
Published: October 2015

An approach of energy minimization in humanoid robots is proposed in our paper. The techniques of dynamic power management method and real-time scheduling method are combined to be used in the humanoid robots. The common components of humanoid robots are motors, sensors, computers and controllers and so on which are electronic systems, and humanoid robots are real-time systems. Therefore, the dynamic power management method is used to dynamically adjust power state of components adaptive to the task’s need to reduce energy consumption, and the real-time scheduling method is applied to schedule multiple tasks and meet the deadlines. Through simulation of the humanoid robot developed by our lab, the feasibility of our method is proved.
Simulation of 8-Degrees of Freedom Based Bio-Inspired Humanoid Robotic Arm Using MATLAB/ADAMS Co-Simulation Environment
Authors: Sudharsan Jayabalan , Karunamoorthy L.
Published: October 2015

This research work presents a dynamic control of a 8 – Degrees of freedom (DOF) based bio-inspired humanoid robotic arm which was simulated using MATLAB / Adams Co-Simulation environment. The robotic arm has been modeled using PRO-E and its invoked in ADAMS and Controlled by MATLAB programming environment. With the help of the simulation results, parameters like torque, position, etc of the system have been analyzed for various trajectories or path of the robot and the results have been discussed in detail. This research work is part of a real time humanoid robot project titled – RALA (Robot based on Autonomous Learning Algorithm).
System of Telecontrol with Two Manipulators
Authors: Katsurin Alexey , Gerasimenko Denis
Published: October 2015

This paper describes the system of telecontrol with two manipulators, that allows to grasp synchronously the object, position and orientation of which is determined by the vision system. The proposed algorithm of the computing system forms the control signals for all drives of manipulators. The simulation results confirm the efficiency of this algorithm and the overall system.
Patient-Driven Hand Exoskeleton Based Robotic with Active Control System for Early Post Stroke Rehabilitation
Authors: bin Ab Patar Mohd Nor Azmi , Komeda Takashi , Low Cheng Yee , Mahmud Jamaluddin
Published: October 2015

The development of a robotic exoskeleton to restore and rehab, hand and finger function is highly competitive nowadays. The robotic exoskeleton is an active actuated mechanism implemented in rehabilitation system, in which each finger attached to an instrumented lead screw mechanism allowing force and position control, according to the normal human setting. The robotic device is a direct driven actuated based on ergonomics measurements, capable to assist in flexion and extension motion. As an adaptation mechanism, it's also compatible with various sizes and shapes of anthropometric human‘s finger. The integration of DC servo motor and lead screw mechanism were the main features of the interface, which allows independent motion of the five fingers with small and lightweight actuators. The device is easily transportable, efficient safety performance, user friendly and offer multiple modes of training potentials. This paper presents the measurements implemented in the system to determine the requirements for finger and hand rehabilitation device, the design and characteristic of the whole system.