bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the Stop Position of the Mobile Manipulator for Painting on Big Parts
Authors: Ren S. , Yang X. , Wang G. , Liu Z. , Yu Q. , Chen K.
Published: March 2016

The industrial manufacturers are pleased to set up robotic manipulators instead of human workers to execute painting tasks which greatly reduces the risk of workers’ being poisoned and is more conductive to maintain stable quality because of the manipulator’s high repetitive accuracy. When the industrial manipulator is employed to paint on big parts, the operating mode is also changed. The manipulator is mounted on a mobile platform, which is usually a NC-machine, to extend its workspace for painting on big parts. And the manipulator starts operation just as the mobile platform arrives at a proper position and stops.

However it is difficult for a human worker to figure out a proper stop position in which the manipulator can reach all goal points with a regular process velocity due to the special mechanical structure of serial revolute joints and the compound free-form surfaces, which is the most significant barrier to develop robotic big-parts painting.

In this paper, we put forward a novel idea based on analysis of the base’s workable location space (BWLS) of the manipulator to solve the stop position optimizing problem in order to get a bigger continuous operating area for the manipulator once stops and improve painting quality. Compared to previous study on the reachability of the end-effector fixing the base of the manipulator, we explore the BWLS while the center wrist point of the manipulator is determined. Through formulating an analytical expression, we can describe the BWLS more precisely and the intersection curves between these workable spaces can be also obtained when the wrist moves to the target points. With considering these boundary surfaces derived from the physical limits of the manipulator, the planning results will be more efficient and reliable.

The optimization results are verified by computer simulation. A 3D model of the manipulator with a mobile platform has been constructed. The painting trajectory for a target plane surface is firstly performed and the corresponding optimized stop position is then provided. Thus the method is proved to be effective and less time cost which could significantly reduce the planning time in comparison with manual operation.
Stress State and Deformation Pattern During the Infeed Swaging of Tube Without Mandrel
Authors: Mu Dong , Zhang Qi , Zeng Fei , Wang Fengjun
Published: March 2016

Infeed swaging is a type of rotary swaging process. It is usually used to reduce the cross section from the beginning to the end of the tube. Compared with the infeed swaging with mandrel, the infeed swaging without mandrel has the advantages of less-loading, chipless forming, giving high production rate and low tool costs. It has been widely used in aeronautic and automotive industries. In this paper, using the finite element (FE) simulation code, TRANSVALOR FORGE 2011, three-dimensional (3D) FE model and experiment were developed to investigate the stress state and deformation pattern during the infeed swaging of tube without mandrel. Results show that the stress state varies with the regions. In the sinking zone, the stress state in the middle of the tube is biaxial compressive, while that at the other regions is triaxial. In the forging zone, the material suffers from tensile axial stress, compressive thickness stress and circumferential stress. After unloading, tensile residual stresses occur at the forging zone and the inner surface in the sinking zone. The maximum tensile residual stress is 69.5MPa, which is 77.3% of the yield stress. In the sinking zone, more metal flows radially inside and the deformation type is compressive. In the forging zone, more material tends to flow along the axial direction. The deformation type in the forging zone is tensile. Moreover, experiments were also conducted to validate the FE model. The experimental and simulated results have a good agreement. After the infeed swaging, the microstructure of the tube became smaller and denser. The metal flow lines are continuous, contributing to improve the strength and the fatigue life of tube.
A Review of Smooth Variable Structure Filters: Recent Advances in Theory and Applications
Authors: Gadsden S. Andrew , Afshari Hamed H.
Published: March 2016

The smooth variable structure filter (SVSF) is a relatively new state and parameter estimation technique. Introduced in 2007, it is based on the sliding mode concept, and is formulated in a predictor-corrector fashion. The main advantages of the SVSF, over other estimation methods, are robustness to modeling errors and uncertainties, and its ability to detect system changes. Recent developments have looked at improving the SVSF from its original form. This review paper provides an overview of the SVSF, and summarizes the main advances in its theory.
A Novel Rotary Magneto-Rheological Damper for Haptic Interfaces
Authors: Topcu Okan , Tascioglu Yigit , Konukseven Erhan Ilhan
Published: March 2016

Haptic interfaces require lightweight, small actuators with high force capability and low friction. In this paper, based on the structure of conventional shear mode disc and drum type MR fluid dampers, a lightweight continuous rotary MR damper working in valve mode is designed for haptic interfaces. The proposed design is compared to shear mode disc-type and drum-type designs with similar torque–to–mass ratio via computer simulations. Mathematical models for the resistant torques of both the shear mode and the valve mode are derived. Subsequently, the finite element analysis of electromagnetic circuit calculations was carried out by FEMM software to perform an optimization of the dimensions of the parts such as gap size and thickness. It is shown that the proposed continuous rotary valve mode MR damper is a fine candidate that meets the requirements of haptic interfaces.
Project Management and Implementation in EcoCAR 3
Authors: Jambor Eric J. , Bradley Thomas H.
Published: March 2016

The EcoCAR 3 competition is the latest iteration of the Advanced Vehicle Technology Competitions sponsored by General Motors (GM) and the Department of Energy (DOE). The competition involves 16 universities from the US and Canada and requires the teams to design, develop, and implement a hybrid Chevrolet Camaro from the platform of GM’s choosing. The Colorado State University (CSU) team is a unique participant in this competition because it implements the program as a subset of the Mechanical Engineering and Electrical Engineering senior capstone courses. The advantages of this arrangement are that EcoCAR 3 can leverage course deliverables to achieve EcoCAR 3 objectives, and that students can receive credit for their efforts in support of the EcoCAR 3 program. The challenges with this approach center around having two sets of deliverables (competition and academic) on overlapping timelines with shared resources. These challenges must be resolved through project management activities to successfully meet all of the deadlines and requirements of each program.
Design and Development of a Low Cost Prosthetic Arm Control System Based on sEMG Signal
Authors: Azab Ahmed M. , Onsy Ahmed , El-Mahlawy Mohamed H.
Published: March 2016

The aim of this paper is to design and develop a low-cost prosthetic arm based on surface electromyography (sEMG) signal activities of the biceps muscle during upper-limb movement. Different methods are described in the literature, but many problems are encountered in dealing with the online processing of raw EMG (rEMG) signals, such as signal sampling and memory requirements. In this paper, the enveloped EMG (eEMG) signal is used as a control signal that reduces signal sampling rate and memory requirements. The relationship between elbow motion and the activity level of the biceps muscle is characterized using relevant extracted features (root mean square (RMS)). Validation of the proposed low-cost system is conducted using comparison with a professional biomedical system (Bioback MP150). In addition, the estimated equation of movements of each subject is estimated based on the recorded data. From this equation, the angle of motion is calculated as the control of the movement of the robotic arm. Finally, the system proposed in this paper considers the eEMG signal rather than the rEMG signal and deals with the signal based on a sample of 1 KHz rather than 10 KHz. This system reduces our target cost (reduction in hardware requirements and processing time) with acceptable accuracy. The experimental results illustrate that the eEMG signal has the same features-print as that of the rEMG signal, and the eEMG signal can generate the control signal required to move the prosthetic arm.
Comparison of Tensile Testing Flow Stress to Orthogonal Plate Machining Flow Stress in FCC, BCC, and HCP Materials at Various Levels of Hardness Using a Videographic Quick Stop Device
Authors: Payton Lewis N. , Hunko Wesley S.
Published: March 2016

Basic and advanced metal cutting research has been an ongoing effort since Cocquilhat’s early work directed towards measuring the work required to remove a given volume of material when drilling in the year 1851. Over the 150+ years since his experiments, one of the persistent issues in metal cutting has been how best to determine the flow stress in a metal undergoing cutting. In all the many models proposed since then, the flow stress of metal flowing in front of a cutting tool has not proven to be the same as the flow stress of metal undergoing a tensile pull. This paper examines the flow stress phenomenon using an improved Videographic Quick Stop equipment at Auburn University.

The orthogonal machining plates and tensile specimens were all cut from the same stock. Tensile testing of the stock was performed immediately prior to the machining of the plates in a standard MTS load frame to allow actual metal cutting experiments to be performed and compared to actual load frame data from the same stock.

Machining was conducted in a specially modified Cincinnati Horizontal Milling machine using an improved Videographic Quick Stop Device (VQSD) to capture the geometry of the cutting formation simultaneously with the forces in the X, Y and Z-axes using a standard Kistler force plate dynamometer. Utilizing the VQSD greatly increases the number of replicates available for statistical analysis by the metal cutting researcher. This allows for comprehensive multivariate analysis of the data with high confidence (> 95%) in the meaning of the results obtained, along with for powerful regression.

The results of the data collection and statistical analysis are then used to populate the various historical models predicting the flow stress in metal cutting. The results indicate that one model is superior to all the other models in predicting the flow stress as predicted by the accompanying tensile test data. Further improvements in this model may lead to instantaneous tensile strength measurement when metal cutting with the need for load frames. This in turn would allow optimization of cutting conditions to match material conditions, resulting in a better product and longer-lived tools.
Development and Characterization of a Portable Atmospheric-Pressure Argon Plasma Jet for Sterilization
Authors: Lin Zhi-Hua , Wu Jong-Shinn , Tschang Chen-Yon Tobias , Su Chi-Feng , Wu Tuoh , Shen Yi-Ning , Liu Chih-Tung , Jang Wen-Yea , Ho Min-Tzu
Published: March 2016

In this study, we would like to develop a portable round argon atmospheric-pressure plasma jet (APPJ) which can be applied for general use of bacteria inactivation. The APPJ was characterized electrically and optically, which include measurements of absorption power, gas temperature and optical properties of plasma generated species. Measured OH* number density at 5 mm downstream was estimated to be 5.8 × 1015 cm−3 and the electron density and electron temperature were estimated to be 2.4 × 1015 cm−3 and 0.34 eV, respectively, in the discharge region. This APPJ was demonstrated to effectively inactivate E. coli within seconds of treatment, which shows its great potential in the future use of general bacteria inactivation and sterilization.
Improved Mechanical Property in Fiber Reinforced Plastic Composites Using Spray Coated CNTs
Authors: Perry Kirsten , Burnett Miles , Demirtas Mehmet , Liu Yingtao , Saha Mrinal
Published: March 2016

Carbon nanotubes have been employed as prominent nanofillers in composite matrix systems to improve the mechanical properties as well as thermal and electrical properties. A spray coating method is being developed as an effective way to deposit carbon nanotubes onto carbon fiber fabrics with good control of network formation. Compared to conventional approaches, such as chemical vapor deposition and solvent based dispersion approach, the proposed method is simple and versatile with the potential for industrial scale-up. In this paper carbon nanotubes are dispersed in solvent with optimized fabrication experimental processing procedures and sprayed on carbon fiber fabrics. Once all the solvent has been evaporated, the coated carbon fiber fabrics are examined using scanning electron microscopy system. We fabricate carbon fiber reinforced composites using an optimized wet layer approach. Both the prepared carbon nanotube coated carbon fiber fabrics and pristine carbon fiber fabrics were used with the conventional epoxy for the composite fabrication. The enhanced mechanical properties of the composites are experimentally characterized, especially focusing on the Mode-I toughness and strength. The experimental results showed that the spray coated CNTs can significantly improve the mechanical properties of composite, especially under the Mode-I fracture load conditions.
Development of a Speech Controlled Robot in an Engineering Design Class
Authors: Xiao Angran , Zhang Andy S.
Published: March 2016

Project based learning (PBL) is a dynamic classroom approach in which students actively explore solving real world problems and gaining knowledge and skills through developing real products. In this paper, we introduce a student project that focuses on the integration of mechanical and electrical components in the development of a speech controlled service robot. The technical details of this project are presented, including the major components, system integration, and the software that enables the functions of the robot. A robot with such functions can be used in many applications such as military operations, speech controlled appliances, etc. Student assessment has shown that this project helps students learn valuable knowledge of product development that are usually only acquired through real world working experiences.
Human Knee Joint Inverse Dynamics Model for Walking and Moderate Squat Exercise
Authors: Caruntu Dumitru I. , Gomez Ricardo
Published: March 2016

This paper deals with human knee and hip joints’ forces in moderate squatting motion. The model developed for squatting is validated through simulations for walking (the stance phase of gait cycle) which are compared with data available in the literature. The knee model is two dimensional and includes tibia, femur, ligamentous knee structures, and muscles. The model is used to investigate the ligament, contact and muscle forces during both moderate squatting and walking.
A Method of Mobile Robotic Drilling Trajectory Planning for Large-Scale Components
Authors: Wang Mengyu , Guo Lianshui , Zhang Yunzhi , Liang Xuemei
Published: March 2016

This paper conducts an in-depth research on mobile robotic drilling trajectory planning for large-scale components. And it proposes a path planning method of step-close for mobile robotic station. According to the thought of “drilling area-robot station-process step”, the drilling order is defined. By adding conditions and simulation, we also present a simple method of optimizing robot posture in this paper. Using the actual position and the nominal position of two reference holes, a correcting algorithm of three-dimensional transformation is introduced to improve the drilling accuracy. Taking the aircraft wing-box drilling as main study object, this paper develops a trajectory planning and a drilling simulation system on the CATIA and DELMIA platform to validate the effectiveness of the methods introduced. Experiments show that the trajectory planning method and the three-dimensional transformation method for correcting drilling position in this paper not only improves the wing-box drilling efficiency and accuracy, but also reduces the production cost.
Spatially Resolved Gelled Propellant Spray Characteristics of Impinging Jets
Authors: Rodrigues Neil S. , Sojka Paul E.
Published: March 2016

The spatially resolved spray characteristics created by the like-on-like impingement of two gelled propellant simulants was experimentally investigated using Phase Doppler Anemometry (PDA). Water based gels of 1.0 wt.-% agar and 1.0 wt.-% kappa carrageenan, which were characterized using the Herschel-Bulkley rheological model, were used as the gel propellant simulants. Spatially resolved measurements for drop size and drop velocity were obtained up to 10 mm away from the centerline along the transverse axis in the plane of the sheet and up to 20 mm away from the centerline along the transverse axis in the plane normal to the sheet. All measurements were obtained at an axial plane 5 cm downstream of the impingement point. Larger D10 and D32 mean diameters and lower mean axial drop velocity Uz-mean were observed for transverse distances away from the centerline of the spray along both the axis in the plane of the sheet and in the plane normal to the sheet.
Additive Manufacturing of Complex Shapes Through Weld-Deposition and Feature Based Slicing
Authors: Panchagnula Jayaprakash Sharma , Simhambhatla Suryakumar
Published: March 2016

Fabricating fully dense and functional metallic components is one of the important challenges in Additive Manufacturing (AM). Additive Manufacturing is a technology in which functional components can be fabricated rapidly and efficiently from their CAD models. It is also referred as Layered Manufacturing (LM) as the object is created by slicing the CAD model into layers and realizing each layer at a time. These layers are thin and stacked or glued together to get the physical shape of the CAD model. However, realizing overhanging features is a difficult task due to deficiency of support mechanism for metals. A separate support structure has to be deposited to build overhanging structures. Although, use of a distinct support material is quite common in non-metallic AM processes, such as Fused Deposition Modelling (FDM), and the same for metals is not yet available. The various techniques in AM process for fabricating metal parts can be mainly classified as laser based, electron beam based and arc based processes. While some Additive Manufacturing processes like Selective Laser Sintering (SLS) employ easily-breakable-scaffolds made of same material to realize the overhanging features, the same approach cannot be extended to deposition processes like laser or arc based direct energy deposition processes. Even though it is possible to realize small overhangs by exploiting the inherent overhanging capability of the process or by blinding some small features like holes, the same cannot be extended for more complex geometries. A different approach to solve this problem is feature based slicing. Unlike uniform and adaptive slicing techniques, where the thickness of a given slice is constant, in feature based slicing inclined slicing; the thickness varies even within a given slice, based on its feature. The current work presents a novel approach for realizing complex overhanging features without the need of support structures. This can be possible by using higher axis kinematics or by adding extra degrees of mobility to the work piece or to the deposition system and suitably aligning the overhang with the deposition direction. Some Vital concepts required in realizing and depositing overhangs are feature based non-uniform slicing and non-uniform area-filling and the same are briefly discussed here. This research will summarize the issues and related approaches in the research, development, and integration. This includes understanding of the weld deposition process by establishing proper geometries, and automated process planning. This technique can be used to fabricate or repair fully dense and functional components for various engineering applications. Although this approach has been implemented for weld-deposition based system, the same can be extended to any other direct energy deposition processes also.
Experimental Investigation on the Transcritical Behaviour of Methane and Numerical Rebuilding Activity in the Frame of the HYPROB-BREAD Project
Authors: Ricci D. , Natale P. , Battista F. , Salvatore V.
Published: March 2016

The HYPROB Program, led by the Italian Aerospace Research Centre, has the aim to increase the Italian capabilities in the design and manufacture of liquid oxygen-methane rocket engines; in particular, the line, named HYPROB-BREAD, has the final goal of developing and testing a ground demonstrator of three-tons-thrust class, regeneratively cooled by liquid methane. Some intermediate breadboards have been conceived, realized and tested to deepen some technical issues: among them a specific breadboard, named MTP-B (Methane Thermal Properties Breadboard), has been designed and tested to investigate thermal characteristics of methane as a coolant, and perform the design validation activity by collecting experimental data. The concept is based on the electrical heating of a conductive material that transfers a thermal load, similar to those experienced in the regenerative cooling chambers, to a channel, having dimensions typical of regenerative cooling jackets. The test campaign has been successfully accomplished by collecting data, in terms of inlet/outlet fluid temperature and pressure, temperature at different stations and depth from the channel bottom surface. A numerical rebuilding activity has been planned to verify the numerical thermal models and engineering tools, adopted for the design of the final demonstrator. Thus, simulations on a fully 3-D model, including inlet and outlet interfaces, were performed on some test conditions after completing a preliminary activity on cold flow tests. The results of the numerical rebuilding are satisfactory since very good comparisons with the experimental data were observed.
Parameter Exploration in Acoustic Scattering Model With Limited Model Information
Authors: Segala David B. , Wettergren Thomas A.
Published: March 2016

In this paper, we fit we explore three different model approximation schemes in order to determine a representative model of measured data. As in many experimental settings where complex phenomenon is challenging to capture, limited sampled points of the physical process are known. However, there is knowledge of an upper and lower bounding solution. In the case where only the sampled points are known, a polynomial fit of order four (with only 5 known sampled points) produces a very crude fit with the largest amount of error. An average of the bounding solutions is able to provide a more accurate fit but still moderately crude. Finally, it is shown that the convex hull of the bounding solution with the sampled points is able to provide a fit with the least amount of error. We demonstrate this by predicting the target strength of an unknown acoustically scattering rigid sphere which is sampled at equally spaced frequencies over a vast range of frequency values.
A Computational Study of Fracture in the Calcaneus Under Variable Impact Conditions
Authors: Kantareddy Sai Nithin Reddy , Fielding Rebecca A. , Robinson Michael J. , Kraft Reuben H.
Published: March 2016

This preliminary study aims to computationally model and study the fracture patterns in the human calcaneus during variable impact loading conditions. A finite element model of the foot and ankle is used to understand the effect of loading rates and orientation of the foot on fracture patterns. Simulations are carried out by applying varying impact velocities of steel plate to the foot & ankle model in accordance with data regarding underbody blasts. These impact velocities are applied to reach a peak in 1.5 ms. Fracture of bone is represented using the plastic kinematic constitutive model with element erosion method, where elements are removed from the simulation after an inelastic failure strain is exceeded. The simulations last for 5 ms to observe the extent of fracture in the calcaneus.

Following simulations, the resulting fracture patterns are compared to available images from experimental impact tests to qualitatively assess the simufutions. A mesh convergence study is performed to determine the level of refinement of mesh necessary to represent this problem. The mesh appears to converge at the refinement level of the medium coarse mesh. The effect of impact velocities on fracture is studied on unjlexed and flexed foot models. At lower velocities, fracture is observed in the form of a single continuous crack, and a pronounced branched type of network is observed at higher velocities. Finally, variation in fracture networks due to variability in strength of the bone is studied. For lower values of failure strain, significantly larger and branched networks of fracture are observed.
A Method to Design Custom-Fit Stent Graft for Abdominal Aortic Aneurism
Authors: Colombo Giorgio , Bartesaghi Simone , Pallares Eduardo
Published: March 2016

Abdominal Aorta Aneurysm (AAA) affects aorta, especially above the iliac bifurcation where the Wall Shear Stress (WSS) is greater. Consequence may be fatal in case of breakage; a way to treat it is Endovascular Aneurysm Repair (EVAR) where a stent graft is placed inside the aorta without open surgery requirement. Because of the standards, stent graft can be chosen between several sizes: in some cases, this device cannot fit perfectly with the anatomy of the patient and this can lead to a not optimal behavior of the prosthesis and further complications.

This study present a method to design and test specific custom-fit stent graft able to better adapt to the patient artery improving the efficiency of the prosthesis and reducing the risk of the migration of the graft as well as the fabric torn. The design method is based on a 3D geometric model of the aorta, generated from CT scan data. Centrelines and geometric data for cross sections along the aorta are the inputs necessary to define the mesh of the stent. A custom algorithm is developed to size the stent in relation to the geometric data of the specific patient; when the frame of the prosthesis is defined, a CAD-based Loft Surface has used to define surfaces between the stent rings. For the bifurcation, again CAD-based Boundary Surfaces is used.

The described procedure has been also applied in a Augmented Virtual Reality simulation of the EVAR and, finally, it permits a CFD simulation to evaluate the behavior of the prosthesis inserted into the aorta.
3D Effects in Cyclorotor Propulsion Systems
Authors: Leger J. , Páscoa J. , Xisto C.
Published: March 2016

A cycloidal propeller is an aircraft propulsion system that is composed by several blades rotating about a horizontal axis perpendicular to the flight direction. The rotor blades prescribe a periodic change on their pitch angle over a cycle of rotation. Many experimental, analytical and numerical studies have been developed in order to calculate force production and power required as well as the real simulation of the blades motion and the cyclorotor mechanical system operation. An important aspect of cycloidal propellers is the study of their efficiency both in hovering state and in forward motion considering 3D effects. For this purpose, it is developed a two-dimensional and three-dimensional CFD model of a cyclorotor whose blades describe the cycloidal path imposed by the pitch mechanical system control. Then, it is taken into account the experimental data for the proper validation. With the validated model, it presented and analyzed the 3D flow field around the cyclorotor under different operating conditions.
Plasma Actuators for Boundary Layer Control of Next Generation Nozzles
Authors: Rodrigues F. , Páscoa José C. , Dias F. , Abdollahzadeh M.
Published: March 2016

DBD plasma actuators are simple devices comprising two electrodes separated by a dielectric layer. One of the electrodes is covered by the dielectric layer and is completely insulated from the other one, which is exposed to the atmosphere in the top of the dielectric layer. The DBD plasma actuator operates by applying to the two electrodes an high voltage at high frequency from a power supply. When the amplitude of the applied voltage is large enough, in the exposed electrode, an ionization of the air (plasma) occurs over the dielectric surface which, in the presence of the electric field gradient, produces a body force on the ionized air particles. This induces a flow that draws ionized air along the surface of the actuator and it accelerates this neutral air towards downstream, in a direction tangential to the dielectric. Herein we will present this next generation plasma actuator for boundary layer control, which is demonstrated on the acceleration of the flow in a Coanda nozzle wall, thus contributing to help vectoring the exit jet flow. It will be shown that using only the plasma actuator it will be possible to vectorize the exit jet flow even under pure axial flow at the nozzle exit. Experimental results are obtained using flow visualization and Particle Image Velocimetry.
Mechanical Properties of Additively Manufactured PEEK Components Using Fused Filament Fabrication
Authors: Rahman Kazi Moshiur , Letcher Todd , Reese Riley
Published: March 2016

Polyether ether ketone (PEEK) is introduced as a material for the additive manufacturing process called fused filament fabrication (FFF), as opposed to selective laser sintering (SLS) manufacturing. FFF manufacturing has several advantages over SLS manufacturing, including lower initial machine purchases costs, ease of use (spool of filament material vs powder material), reduced risk of material contamination and/or degradation, and safety for the users of the equipment. PEEK is an excellent candidate for FFF due to its low moisture absorption as opposed to other common FFF materials, such as Acrylonitrile Butadiene Styrene (ABS).

PEEK has been processed into a filament and samples have been manufactured using several build orientations and extrusion paths. The samples were used to conduct tensile, compression, flexural, and impact testing to determine mechanical strength characteristics such as yield strength, modulus of elasticity, ultimate tensile strength and maximum elongation, etc. All tests were conducted at room temperature. A microscope analysis was also conducted to show features on the failures surfaces. The mechanical property results from this study are compared to other published results using traditional thermo-plastic manufacturing techniques, such injection molding.

Tensile testing was conducted at three raster orientations, 0°, 90° and alternating between 0° and 90°. Average ultimate tensile stresses were determined to be 73 MPa for 0° orientation, and 54 MPa for 90° orientation, with alternating 0°/90° orientations of 66.5 MPa. Compression testing was conducted at two raster orientations, 0° and alternating between 0° and 90°. Average ultimate strength for the single orientation direction was 80.9 MPa with the alternating orientations at 72.8 MPa. Flexural testing was conducted at three raster orientations, 0°, 90° and alternating between 0° and 90°. Ultimate flexural stress was determined to be 111.7 MPa for 0°, 79.7 MPa for 90°, and 95.3 MPa for orientations alternating between 0° and 90°. Finally, impact testing was conducted at three raster orientations, 0°, 90° and alternating between 0° and 90°. Average impact energy absorbed was determined to be 17.5 Nm in the 0° orientation, 1.4 Nm in the 90° orientation, and 0.7 Nm for the alternating 0° and 90° orientations.
Filtering Techniques for Accurate Identification of Clinician Hand Posture
Authors: Hodes Alex T. , Weiner Carl P. , Fang Huazhen , Kieweg Sarah K. , Wilson Sara E.
Published: March 2016

Inertial and magnetic sensors are commonly used to determine orientation as they do not rely on a line of sight [1, 2]. There are many different techniques to fuse inertial measurement unit (IMU) data and obtain useful rotational data [1–3]. This study uses two separate data fusion techniques; a direction cosine matrix-based (DCM) technique and a quaternion-based Extended Kalman Filter (EKF) technique [1–3]. These techniques were altered based on performance metrics to weight sensor data when certain sensors proved not as reliable as others [2]. IMU sensors were tested on a hand mannequin and filters were developed using MATLAB software. Simulation results displayed a root-mean-squared error of less than .06° for each rotation angle. Experimental results maintained errors of less than 8° in each rotation angle.
Effect of a New Vortex Generator on the Performance of an Axial Compressor Cascade at Design and Off-Design Conditions
Authors: Diaa Ahmed M. , El-Dosoky Mohammed F. , Ahmed Mahmoud A. , Abdelhafez Omar E.
Published: March 2016

Secondary flows are noxious to axial compressor performance. To overcome and control those secondary flows, vortex generators are used as a passive control device. Controlling secondary flows will lead to a further improvements in the compressor performance. A new design of vortex generator is considered in this investigation in order to control secondary flows in axial compressor cascade at design and off-design conditions. Numerical simulations of a three-dimensional compressible turbulent flow have been performed to explore the effect of the vortex generators on the reduction of secondary flows. Six different incidence angles are used for the off-design operation investigations. Based on the simulation results, the pressure, velocity, and streamline are used to follow up the development of the secondary flows. Thence, total pressure loss coefficient, static pressure rise coefficient, difference in flow deflection angle, and diffusion factor are estimated. Results indicate that vortex generators have a significant effect on the development of secondary flows at off design operation as they cause a reduction in total pressure loss, they also affect the loading behavior of the cascade as they cause a slight change in the cascade deflection, and a slight decrease in the diffusion factor which causes unloading of the blade. Static pressure rise is significantly reduced at negative incidence angles while a slight reduction occurs at positive incidence angles. In a word, the new design of the vortex generator enhances the cascade aerodynamic performance and enlarges the operating range of the cascade towards the positive incidence region.
Control of Centrifugal Instability in Vortex-Surface Interaction
Authors: Kumar Vaibhav , Hiremath Nandeesh , Shukla Dhwanil , Thorrell Nikolaus , Komerath Narayanan
Published: March 2016

The interaction of a rotating conical flow with a solid surface generates a centrifugal instability. This occurs in the flow over the wings of certain types of aircraft at high angles of attack. Efforts at our laboratory have detected such structures using near-surface flow diagnostics, and shown that they can be effectively alleviated using passive flow control near the surface. Their alleviation removes the narrowband spectral peak at the nominal location of vertical fins on these aircraft. This paper explores the substitution of active flow control techniques that remain conformal to the surface and are only powered during high angle of attack operation. The occurrence of the phenomenon and its 15-dB alleviation with geometric fences are shown on a rounded-edge 42-degree swept, cropped delta wing at 25 degrees angle of attack. The feasibility and power requirements for the plasma actuator are estimated in this paper. The generation of counter-rotating vortices using a double dielectric barrier discharge actuator is demonstrated.
Development and Optimization of a Paper Punching System
Authors: Sousa João , Pinho Tiago , Figueiredo Luís , Mendonça João , Machado José
Published: March 2016

This paper focuses on the study and optimization of binding machine’s paper punching system, especially on the required actuating torque. The mechanical properties of paper, which are required to perform numerical simulation, are revised from current bibliography. Various hole types, required for the different binding systems are analyzed as well as the puncher’s geometry. The actuating mechanisms responsible for the punching movement from several binding machines are presented. Torque measurements were performed to demonstrate the potential improvements from a new puncher configuration and/or actuating mechanism.
A Method to Estimate Residual Stress in Metal Parts Made by Selective Laser Melting
Authors: Wang Xiaoqing , Chou Y. Kevin
Published: March 2016

Accurate evaluation of residual stresses in structures is very important because they play a crucial role in the mechanical performance of the components. As residual stresses can be introduced into mechanical components during various thermal or mechanical processes such as heat treatment, forming, welding and additive manufacturing. As an additive manufacturing method, selective laser melting (SLM) has become a powerful tool for the direct manufacturing of three dimensional nano-composite components with complex configurations directly from powders using 3D CAD data as a digital information source and energy in the form of a high-power laser beam. Therefore, the application of the SLM technology is necessary to manufacture Inconel 718 superalloy, which has been widely employed in industrial applications due to its remarkable properties. Hence, it is critical to measure and reduce the residual stress in the Inconel 718 parts formed by SLM due to rapid cooling and reheating. In this study, the process-induced residual stress in Inconel 718 parts produced by selective laser melting (SLM) has been investigated using the model established by Carlsson et al., which is an instrumented indentation technique based on the experimental correlation between the indentation characteristic and the residual stress. The samples were sectioned from an Inconel 718 block along its build direction, and subsequently prepared with general metallographic methods for Vickers indentation and measurements by optical microscopy. The residual stress on the scanning surface (Z-plane) and side surface (X-plane) at different build heights have been evaluated in micro-scale with the contact area, indentation hardness and the equai-biaxial residual stress and strain fields. The results show that the residual stress is unevenly distributed in the SLMed parts with some areas have an maximum absolute value around 350 MPa, about 30 percent of the yield strength of Inconel 718. The average residual stresses in the Z-plane and X-plane samples are tensile and compressive, respectively. Besides, the residual stress does not change significantly along the building direction of the part. Moreover, the Vickers hardness of the parts built with the SLM process is comparable to the literature, and the X-plane surface has a higher hardness than the Z-plane surface. The microstructures and texture evolution of the SLM processed Inconel 718 alloy are also investigated. The X-plane shows the columnar structure due to the large temperature gradient while the Z-plane presents the equiaxed structures. The random texture is shown in the SLM processed specimens.
Solving Koffee Karousel Design Problems: A Case Study in the Senior Mechanical Engineering Design Student Project
Authors: McCall Casey , Bzymek Zbigniew M.
Published: March 2016

The University of Connecticut Department of Mechanical Engineering has developed an industry recognized Senior Design Capstone course. The course provides fourth-year students the opportunity for a “major design experience in which they apply the principles of engineering, basic sciences, and mathematics to model, analyze, design, and realize physical systems, components or processes, and it prepares students to work professionally” [1]. The course is taught by a class instructor and is supported by the faculty of the Mechanical Engineering department at UConn. In the 2013–2014 academic year there were over 40 projects in the course. This paper presents the issues and challenges that students faced when working on a project for Koffee Karousel’s coin-operated K-Cup vending machine. Work on the project began with the problem statement, and was followed by the generation of possible solutions (accepting the most promising ones) and finally, choosing the ideal solution. The subsequent steps involved preliminary and detailed design, structural analysis, creating a 3D CAD representation, generating drawings, and producing a prototype. The prototype was then tested to verify its capabilities. The example of switching from a coin-operated design, with its limited potential use, to an electronically operated solution is described in this paper. The objective of this senior design project was to implement a credit card reader onto the original Koffee Karousel design. To accomplish this goal, a redesign of the Koffee-Karousel’s coin mechanism was required. An electrical engineering team of four students worked independently on the credit card and display setup, while a mechanical team worked on a lever mechanism and gears activated by the validation of a credit card. The implementation of this new mechanism included designing a replacement face, a couple of brackets for electrical hardware, and several new parts, including an actuator and a mini-stepper motor. In addition, students designed the new cam that would interface with stepper motor. Some parts were accepted from the current design of the lever and ejector. The new design still allows the customer to choose which K-Cup flavor they want by hand by operating a rotating knob at the top of the carousel, but no longer requires the user to trigger the ejector mechanism manually. Students tested the new mechanism to ensure it was not only efficient, but also worked properly. The stresses on each individual part were calculated for the first design iteration to ensure the new design would not yield or fail over time due to fatigue.

The project and its challenges are described in this paper, as well as the students’ contributions to the design of the Karousel mechanisms, switching it from a purely mechanical to a mechatronik solution.
Thermal Error Modeling Based on Genetic Algorithm and BP Neural Network of High-Speed Spindle System
Authors: Ma Chi , Zhao Liang , Shi Hu , Mei Xuesong , Yang Jun
Published: March 2016

In order to improve the prediction accuracy of the thermal error models, grey cluster grouping and correlation analysis were proposed to optimize and select the heat-sensitive points to improve the performances of the thermal error model and minimize the independent variables to reduce modeling cost. Subsequently, the neural network with back propagation (BP) algorithm was proposed to construct the strongly nonlinear mapping relationship between spindle thermal errors and typical temperature variables. However, the shortcomings of the BP network restricted the accuracy, robustness and convergence of thermal error models. Then, a genetic algorithm (GA), which regarded the reciprocal of the absolute value sum of the differences between the predicted and desired outputs as the number of nodes in the hidden layer, was proposed to optimize the structure and initial values of the network. And the number of the nodes in the hidden layer can be determined by performing such operations of GAs. Moreover, the reciprocal of the sum square of the difference between the predicted and expected outputs of individuals is regarded as the fitness function and the weights and thresholds of the BP neural network are optimized by setting the control parameters of GAs. Then, the elongation and thermal tilt angle models of high-speed spindles were proposed based on BP and GA-BP networks and the fitting and prediction abilities were compared. The results showed that the grey cluster grouping and correlation analysis could depress the multicollinearity among temperature variables and improve the stability and accuracy of the thermal error models. Moreover, although the traditional BP network had better fitting ability, its convergence and generality were far worse than the GA-BP model and it is more suitable to use the GA-BP neural network as the thermal error modeling method in the compensation system.
Numerical CFD Simulation and Test Correlation in a Flight Project Environment
Authors: Gupta K. K. , Lung S. F. , Ibrahim A. H.
Published: March 2016

This paper presents detailed description of a novel CFD procedure and comparison of its solution results to that obtained by other available CFD codes as well as actual flight and wind tunnel test data pertaining to the GIII aircraft, currently undergoing flight testing at AFRC.
The Creation of Collaborative Cyber Physical Environments for Micro Assembly
Authors: Lu Yajun , Cecil J. , Zafar Zak
Published: March 2016

Micro assembly refers to the assembly and manipulation of micron sized devices. This paper discusses an innovative cyber physical framework for the domain of micro assembly, which includes both cyber and physical components and resources. An advanced Virtual Assembly environment has been developed which is integrated to an assembly planning module and a path planning module. A cloud computing based approach is proposed to support collaboration and sharing of process engineering activities including assembly simulation scenarios and camera monitoring tasks among the distributed resources.
Design of an Electro-Mechanical Device for Knee Loading Applications
Authors: Prabhala Sai Krishna , Anwar Sohel , Yokota Hiroki , Chien Stanley
Published: March 2016

Mechanical loading of the knee is an innovative modality developed for rehabilitation of the knee joint as well as the femur and tibia that are subjected to bone fractures, osteoarthritis and osteoporosis. Loading essentially applies a lateral and periodic force to the knee joint [1]. In this paper, we propose the design of an electro-mechanical device that is capable of applying such dynamic loads. The key variable attributes of this device are the magnitude of the loading force, together with displacement and frequency. A DC motor with a controller actuates the device to produce the necessary force. The loading force is applied to the knee by a set of pads in a restricted linear motion. The operation of the device is approximated using the software package, SimMechanics of MATLAB. The simulations show that the device is capable of producing a suitable loading force with desired frequency. This simulation helps in constructing the device and performing experiments with appropriate frequencies. The device is expected to stimulate the fluids in porous skeletal matrix, resulting in strengthening the knee and bones. It can be employed for clinical trials for necessary evaluations and improvements.
Determination of Anisotropy Parameters via the Optimization Process of V-Bending
Authors: Ozturk F. , Toros S.
Published: March 2016

In recent years, the use of optimization methods in sheet metal forming has been increased remarkably. In the finite element simulation of the sheet metal stamping operations, the model parameters are determined from the several tests like tensile, compression, and biaxial stretching tests (bulge test). In this study, Yld2000-2d anisotropic yield function parameters are determined for DP800 advanced high strength steel using a 60° V-shaped die bending process. The difference between the simulation and experiment is found to be 1 degree using the classical determination method of the anisotropy parameters. The difference is 0.1 degree using the optimization method.