bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a Graphical User Interface for Design of Thin Curved Beams
Authors: Navaee Shahnam
Published: October 2013

The problem of nonlinear bending of beams has been of special interest to many engineering mechanics researchers through the years. In the presented paper, the development of an interactive Graphical User Interface (GUI) module for investigating large deflections of circular shaped flexible beams subjected to an end concentrated load is discussed. The numerical computations in the developed module are performed using various special tools available in MATLAB. The module employs the GUIDE (Graphical User Interface Development Environment) feature of this software package to allow the user to interactively prescribe various beam and loading parameters to generate the output in the desired form. Even though MATLAB is widely used in many educational institutions and corporations all across the world, the utility of the GUIDE feature of this powerful tool is relatively unrecognized or underutilized. The developed module can serve as an effective and invaluable tool for the design of flexible beams.

In an earlier paper of the author published in the proceedings of the 2009 ASME International Mechanical Engineering Congress and Exposition (IMECE), the development of a toolkit created using LabVIEW for determining multiple equilibriums configurations of straight cantilever beams subjected to inclined end loads were discussed. The present paper additionally compares and contrasts some of various important features of these two premier engineering software tools (MATLAB & LabVIEW) while presenting the solution for this new problem. The paper can be of special interest not only to the researchers specifically interested in the problem of large deformations of flexible structural components, but also to those searching to find a perfect tool to investigate other class of engineering problems.
Actuation of Carbon Nanofiber Reinforced Electro-Active Paper Actuators
Authors: Chowdhury Nargis A. , A.-Jumaily Ahmed , Ramos Maximiano V. , Uddin Afsar , Robertson John
Published: October 2013

Actuation of two types of electro-active paper actuators composed of functionalized carbon nanofiber, polypyrrole, and regenerated cellulose (FCNF/PPy/RC) and functionalized carbon nanofiber, ionic liquid, and regenerated cellulose (FCNF/IL/RC) is evaluated for different preparation processes. FCNF/PPy/RC nanocomposite films are prepared by dispersing functionalized carbon nanofiber and polypyrrole into cellulose solution in DMAC/LiCl, and then casting the solution onto glass. FCNF/IL/RC nanocomposite films are fabricated simply by adopting a bimorph configuration with a regenerated cellulose-supported internal ionic liquid electrolyte layer sandwiched by electrode layers with a view to getting quick and long-lived operation in air at low applied voltage. The electrode layers include functionalized carbon nanofiber, ionic liquid and regenerated cellulose. The results indicate that the bending displacement decreases with increasing frequency and increases with increasing voltage for both types of actuators. These low voltage driven solid state actuators show maximum stress and strain of 12.73 MPa and 3.0%, respectively, which are comparable with other low-voltage driven solid-state electro-active polymer actuators. The advantages of these types of actuators are their ability to perform well in air and easy process of fabrication.
Study for Starting Characteristics of Scramjet Engine Test Facility (SETF)
Authors: Lee Yang Ji , Kang Sang Hun , Yang Soo Seok
Published: October 2013

Korea Aerospace Research Institute started on design and development of a hypersonic air-breathing engine test facility from 2000 and completed the test facility installation in July 2009. This facility, designated as the Scramjet engine test facility (SETF), is a blow-down type high enthalpy wind tunnel which has a pressurized air supply system, air heater system, free-jet type test chamber, fuel supply system, facility control/measurement system, and exhaust system with an air ejection. Unlike most aerodynamic wind-tunnel, SETF should simulate the enthalpy condition at a flight condition. To attain a flight condition, a highly stagnated air comes into the test cell through a supersonic nozzle. Also, an air ejector of the SETF is used for simulating altitude conditions of the engine, and facility starting. SETF has a storage air heater (SAH) type heating system. This SAH can supply a hot air with a maximum temperature of 1300K. Using the SAH, SETF can achieve the Mach 5.0 flight at an altitude of 20 km condition. SETF has a free-jet type test cell and this free-jet type test cell can simulate a boundary layer effect between an airplane and engine using the facility nozzle, but it is too difficult to predict the nature of the facility. Therefore it is required to understand the starting characteristics of the facility by experiments. In 2009, a Mach 3.5 test of SETF was done for acceptance testing which is a maximum air supply condition of 20 kg/s. SETF showed the facility efficiency of a 100% without a test model at the Mach 3.5 condition. In 2010, a Mach 6.7 aerodynamic test campaign with a scramjet engine intake. But SETF could not start at the Mach 6.7 condition with the existing ejector system at that time. To get a facility starting, we modified the ejector system. After modification of the ejector system, SETF started at the Mach 6.7 condition with a facility efficiency of 58%. In this paper, the starting characteristics of the SETF with various flight conditions, and modifications of the ejector system will be described.
Investigation on Wear Behavior of Electrostatic Micro-Solid Lubricant Coatings Under Dry Sliding Conditions
Authors: Paturi UmaMaheshwera Reddy , Suresh Kumar Reddy Narala
Published: October 2013

Dry sliding experiences high friction and wear thus influencing the life and quality of the parts under sliding. To provide low friction and improve wear resistance, solid lubricants have an edge over conventional choice. This article features a specific study of the application of solid lubricant in dry sliding operations and presents its influence on wear resistance. Using a pin-on-disc tribometer designed according to ASTM G99 standard, dry sliding wear tests on aluminum alloy AA6351-T6 specimens were performed against uncoated EN31 steel and molybdenum disulphide (MoS2) coated EN31 steel discs. In this study, counter surfaces (discs) were coated with micron sized MoS2 solid lubricant powder particles using electrostatic spray coating (ESC) method. The best results for wear volume and friction coefficient (minimum values) were registered when aluminum specimen slid against MoS2 coated EN31 steel. Outcome of this study shows that the presence of solid lubricant film on disc specimen will greatly influence the sliding performance of pin material in lubricating and preventing wear through reduction in the frictional force due to presence of lamellar structure as a transfer film and favorable change in sliding interaction.
Analytical and Numerical Study of Hard Rock Cutting With Roller Disc Cutters
Authors: Serati Mehdi , Alehossein Habib , Williams David J.
Published: October 2013

Steel roller discs are an efficient mechanical tool for cutting soft to medium strength rocks in both civil and mining projects. However, their application for hard rock cutting has been hindered since steel discs wear quickly and fail prematurely due to high concentrated stresses generated at the sharp corners and thin elements of the disc. To overcome this problem, the current generation roller discs comprises a steel shaft connected to a tungsten carbide (WC) disc. In other words, while the material of the disc itself is replaced by a stronger WC material, steel continues to be used for the shaft body.

In this paper, to comprehend the influence of material parameters on the induced stresses inside different parts of a roller cutter, an analytical closed-form solution and a series of finite element (FEM) numerical studies are performed. By considering the problem as a traction boundary-value problem in an elastic domain, the analytical solution is based on the Airy stress formulation in Cartesian coordinates with a Fourier series representing the boundary conditions. The analytical result is developed for both plane stress and plane strain conditions, encompassing all possible loading configurations and shaft geometries. To verify the numerical models, these results are also compared with laboratory experimental data obtained from cutting granite using mini discs for the penetration range 1 to 3 mm.
Design of Short-Pipe Restrictor of Hydrostatic Thrust Bearings
Authors: Nakao Yohichi , Nakatsugawa Shota , Komori Masataka , Suzuki Kenji
Published: October 2013

High stiffness hydrostatic bearings are needed in order to achieve precise motions of the machine components of ultra-precision machine tools or other precision machines. Design procedure of restrictors of hydrostatic thrust bearings, making bearing stiffness maximize under given conditions, is considered in the paper. In particular, the paper focuses on design of short pipe restrictors that are used in the hydrostatic thrust bearings in many industrial applications. Derived mathematical model predicting load capacity and stiffness of the hydrostatic bearings with short pipe restrictors are verified by compared with experimental results. Based on the derived mathematical model, an optimum condition of a ratio between the diameter and length of the short pipe restrictor is then derived. Designed short pipe restrictors are used in a water hydrostatic thrust bearing. Then the experimental results show that the bearing stiffness significantly increased. It is noted that the optimum condition of the restrictors is represented by defined non-dimensional parameters.
Hydrothermal Ageing Mechanism of Natural Fiber Reinforced Composite in Hot Water
Authors: Liao Mengyuan , Yang Yuqiu , Yu Ying , Hamada Hiroyuki
Published: October 2013

As well known, sustainability issues represented by the environment and resource protection have been paid close attention nowadays. Natural fiber has been an increasing interest and promising as reinforcing fiber in polymeric composites due to its low density, cost, acceptable specific strength and biodegradation. Even though, the principle challenge for natural fibers used as reinforcement is their internal strong water-absorption ability when the exposed in wet and water environment.

Long-term hydrothermal degradation behavior of Glass reinforced composite (GFRP) and jute reinforced composite (JFRP) have been discussed in previous study on the basis of the great amount of physical and mechanical testing results. As former working reported, gained water content increases linearly against the square root of aging time followed by gradual increase trend in longer duration both in JFRP and GFRP. In particularly, JFRP’s weight loss performance occurred earlier with higher value compared to GFRP. However, water absorption and weight loss mechanism, relationship between weight change and retention of mechanical property for JFRP didn’t report and illustrate clearly and extensively. Therefore, in order to figure it out comprehensively, the current study was focus on hydrothermal ageing mechanism and corresponding degraded mechanical behavior.

Firstly, 2 layers of deeply dried and natural dried jute woven fabric reinforced unsaturated polyester were fabricated by hand-layup method. The cut samples were immersed into 80°C hot water bath for predetermined durations and inspected by ultrasonic wave. Afterwards, 3-point bending test with acoustic emission (AE) measurement was carried out for aged samples. The weight change mechanism, evolution of internal deterioration and mechanical property along with ageing time was investigated. The result indicated that JFRP can absorb water easily and quickly compared with GFRP owing to jute fiber’s hydroscopic nature. Weight loss was caused as a result of resin particle loss and pectin dissolution from the developed micro-crack owing to hydrothermal water environment. What’s more, internal serious deterioration occurred after 24 hours immersion leading to larger reduction of mechanical property.
Optimization of Induction Hardened AISI 1040 Steel by Experimental Design Method and Material Characterization Analysis
Authors: Onan Mert , Baynal Kasım , Ünal H. İbrahim , Katre Furkan
Published: October 2013

Nowadays, some of the steel parts have been applied induction hardening for better mechanical properties in the automotive and aerospace industry sectors. Induction hardening is commonly used in steels, are high magnetic permeability. Martensite formation was observed application as a result of non-diffusion transformation after induction hardening. At this period, there were chosen three factor such as power supplied, scan rate, distance between work piece and coil, were affected material properties. Developed response variables such as surface hardness and case depth were determined after the experiments were done in the industrial conditions. In this study, data were taken by Taguchi method using L27 experiment orthogonal arrays table. Analysis of Variance (ANOVA) was employed with the help of data taken and regression equation was determined. As a result of these experiments and analyses, the optimization of the process conditions for induction hardened steel was investigated. As a consequence of the optimization, microstructural characterization using Light microscopy was carried out to determine the effects of the hardness from the outer surface to the center and nevertheless transformations associated with structural changes are investigated and so that results are determined.
A KBE Design Methodology to Support Li-Ion Battery Cooling for Hybrid and Electric Vehicles
Authors: Landi Daniele , Cicconi Paolo , Germani Michele
Published: October 2013

In a scenario of a small and customized production of Electric Vehicles, it is important to have methodologies and tools able to guarantee high flexibility, good quality, and reduced time to market. The optimisation of electric motors and battery design stages is a key factor to achieve the expected results. Specific activities such as design automation, virtual prototyping and simulation are fundamental to obtain high-performance customised solutions. In this context the study of cooling systems for Li-Ion battery packs is one of the most important problems regarding EV and PHEV powertrain design.

The proposed research presents a Knowledge Based methodology to support the cooling design of a battery pack and an analytical tool to evaluate the temperature and heat generation due to electrochemical reactions. All the research project is finalized to a definition of a Knowledge Based System to define a battery layout including engineering knowledge. The current strategies of battery pack design depend on the market size. In particular, the research activity is focalized on customized production of a SME (Small Medium Enterprise).

The main question concerns the estimation of heat generated from electrochemical reactions in a single battery cell. In order to achieve these objectives, a preliminary phase for knowledge acquisition is necessary and a process of formalization has been carried out using the Knowledge Management methods. A first prototype of the Knowledge Based Engineering tool has been developed to determine the optimal cooling condition of a battery pack. The main module is based on an analytical approach which has been formulated to evaluate the average thermal flow generated by a standard LiFePO4 polymeric cell at different values of current and state of charge (SOC). This method can be used for different types of geometry and different chemical compositions. Finally, the proposed approach has been validated by experimental measures and numerical simulations in collaboration with a medium enterprise of electric energy storage systems and light ecological vehicles.
Microdrilling of Biocompatible Materials
Authors: Mohanty Sankalp , Wells Stephen , Hung Wayne
Published: October 2013

Product miniaturization trend is inevitable. The needs for minimum invasive surgery, smaller sensors for smart machinery, packing more features on a product… require mass production of smaller components from engineering materials. Fabrication of microcomponents requires knowledge of micromachining to avoid costly tool failure and part damage. This research investigates microdrilling of commercially pure titanium, nickel titanium (Nitinol), and 316L stainless steel.

A surface was polished and drilled in rows of ten holes. Through hole drilling at 6:1 aspect ratio was performed on NiTi sheets while blind holes were drilled at 10:1 aspect ratio on Ti or 316L blocks. Microdrills with 100–150 μm diameter and 1.5–3.5 mm flute length were utilized up to 50,000 rpm in minimum quantity lubrication. Finite element models were developed to find upper limits of drilling parameters. Flank wear of 15μm on fine grained WC-Co uncoated tools and peeling of coating layer were used as tool life criteria. Scanning electron microscopy was used to observed tool failure mechanism. Tool life modeling and hole quality were performed to evaluate and compare tool performance.

Although successfully drilling all materials at 10:1 aspect ratio, excessive built-up-edge (BUE) was found on microdrills at all drilling parameters. Such BUE effectively blunted the drill tips and caused drill wandering, degraded hole quality due to rubbing against the drilled wall, work-hardened the drilled surface and accelerated drill wear, and formed burrs at both entrance and exit ends. Wear of a microdrill at the outer corner was more pronounced when drilling CP titanium, but attrition wear at chisel edge was more significant for 316L stainless steel. The classical Taylor equation for macromachining was applicable in microdrilling to rank tool performance and machinability of tested materials. For the same cutting speed of 20 m/min and comparable drilling distance of about 35 mm, CP titanium can be microdrilled 400% faster than 316L stainless steel when applying 0.1 μm/flute chip load for the former and 0.02 μm/flute for the latter. The AlTiN coated drills improved tool life by at least 120%. This coating reduced BUE, drastically improved hole position accuracy by 115%, and decreased hole diameter variation from 0.110% to 0.003% for each mm of drilling distance.
Reverse Engineering the Structure and Function of the Allegheny Mound Ant Neck (Insecta, Hymenoptera, Formica, Exsectoides)
Authors: Nguyen Vienny N. , Lilly Blaine W. , Castro Carlos E.
Published: October 2013

Insects as mechanical systems have been optimized for form and function over millions of years. Ants, in particular, can lift and carry extremely heavy loads relative to their body mass. Loads are lifted with the mouthparts, transferred through the neck joint to the thorax, and distributed over six legs and feet that anchor to the supporting surface. While previous research efforts have explored attachment mechanisms of the feet, little is known about the mechanical design of the neck — the single joint that connects the load path from the thorax to the head. This work combines mechanical testing, computed tomography (CT) and scanning electron microscope (SEM) imaging, and computational modeling to better understand the mechanical structure-function relation of the ant neck joint.
Optimization of Failure Rate of Centrifugal Pumps Using Genetic Algorithm
Authors: Makarachi Peymaan , Pourgol-Mohammad Mohammad
Published: October 2013

Centrifugal pumps are the most common type of kinetic pumps, and are used most often in applications with moderate to high flow and low head. In order to increase the reliability of the pumps, researches have been conducted on pump design and maintenance approaches in recent years in order to reduce their failure rates. In this article, Genetic Algorithm (GA) is used to find the optimum value for the total failure rate of a centrifugal pump. The total failure rate of the pump is modeled here as a combination of the failure rates of its individual components such as pump seals, shaft, bearings, casing and fluid driver ( by a weakest link model).

Considering that all failure modes are statistically independent and any component failure breaks down the pump, the pump total failure rate is the sum of the components’ failure rates. The failure rate function of seals, shaft, bearings, casing, and fluid driver components which are given in [1], are used as objective functions in the optimization problem. Finally, the optimized parameters and failure rate value of the pump’s specific components are obtained.
Study on the Degradation Mechanism of the Urushi Products
Authors: Shimode Yutaro , Endo Atsushi , Narita Chieko , Higashi Seiji , Murakami Masuo , Takai Yuka , Yasunaga Hidekazu , Goto Akihiko , Hamada Hiroyuki
Published: October 2013

Japanese lacquer is called “Urushi” in Japanese. Urushi have meanings such as Urushi tree, its resin and also Urushi crafts. Urushi has been used 9000 years ago in Japan. In this long history, Urushi crafts techniques have been developed, refined and inherited by many Urushi craftspeople. As a result, Urushi affect Japanese culture and aesthetic feeling greatly.

Urushi has various characteristics. For example, Urushi coating surface is very smooth and glossy. And more, Urushi is strong to acid and alkali. However it is very weak to ultraviolet rays. As a result, Urushi coating is degraded very quickly in sunlight.

In this study, 6 specimens were prepared by painting 6 kinds of Urushi resins on PMMA (polymethylmethacrylate) boards. Weathering tests of these 6 specimens were done to clarify the degradation of Urushi coating. Additionally, L* value (Brightness), C* value (Chroma) were also measured by spectrophotometric colorimeter to investigate the influence of the degradation on the optical characteristics. Both L* value and C* value were increased after weathering test in most specimens. Glossiness values of specimens were measured by gloss checker. As a result, glossiness values were decreased after weathering test in most specimens.

There was a difference in advance of degradation according to the kind of Urushi. Then when Urushi is used, there are necessities of proper use and change of refining method for Urushi.
Investigation of Size Scale Effects on the Fatigue Crack Growth Characteristics of an Aluminum Alloy
Authors: Prakash Raghu V. , Satheesh Kumar S.
Published: October 2013

Size scale effect on the fatigue crack growth characteristics of 6063 aluminum alloy is examined in this paper. This is important, as often, a small scoop of material is removed from an in-service component or structure such as pressure vessels, chemical plants and pipe lines are used to decide on life extension. Constant amplitude fatigue crack growth tests were carried out using single edge notched (SENT) specimens and compact tension (CT) specimens to study the effect of size scale on the fatigue crack growth behavior of the material. The thicknesses of the specimens were varied from 10 mm to 0.36 mm. The size of the test specimens were varied from the ASTM standard size to miniature size of 20 mm × 5 mm × 0.36 mm. Tests were conducted at two different stress ratios in load control mode to study the effect of stress ratio on fatigue crack growth rate (da/dN). Seven point incremental polynomial methods was used to deduce the (da/dN) values to plot the fatigue crack growth curves for different specimens. The fracture surfaces were examined under a scanning electron microscope (SEM) to understand the nature of crack propagation at initial, intermediate and terminal stages of crack growth.
Jute Fiber Reinforced Polymeric Composites With Flexible Interphase
Authors: Koshino Tetsushi , Aly-Hassan Mohamed S. , Hamada Hiroyuki
Published: October 2013

In this research, the flexible interphase concept was introduced to enhance the poor mechanical properties of jute fiber reinforced unsaturated polyester matrix composites. The jute cloth reinforcement was obtained from recycled coffee bags. These jute cloths after washing by water and drying were soaked in mixture of Polybutadiene Epoxydied as flexible resin and acetone for 10 seconds. Several mixtures consist of 0, 2, 3.5, 5 and 8 wt% of Polybutadiene Epoxydied and 100, 98, 96.5, 95 and 92 wt% of acetone, respectively, to form flexible interface around the jute fibers. Jute cloth reinforced unsaturated polyester matrix composites with different flexible interphase incremental weight ((Wa-Wb)/Wb) ratios were fabricated by hand lay-up method and examined by a series of mechanical tests. The mechanical testing including tensile, bending, Izod strength impact and drop impact was carried out for these composites to evaluate the effect of the flexible interphase and acetone on the jute cloth composites. The flexible interphase succeed to control the mechanical properties of jute fiber reinforced unsaturated polyester matrix composites. Inserting flexible interphase between unsaturated polyester matrix and jute fibers leads to smooth fluctuation, less matrix cracking, in the second part after the knee point of each stress-strain curve as exhibited in composites with higher flexible interphase incremental weight ratio. This means not only the brittle matrix but also interface/interphase dominates the multiple matrix cracking behavior in jute cloth reinforced unsaturated polyester matrix composites. Inserting flexible interphase between unsaturated polyester matrix and jute fibers leads to less number of multiple cracking as shown in the second portion of flexural stress-displacement curve. This means the number of multiple cracking are dominated by flexible interphase. The impact strength of jute cloth reinforced unsaturated polyester matrix composites with flexible interphase incremental weight ratio of 1.2% is higher than that of jute cloth reinforced unsaturated polyester matrix composites without flexible interphase by about 45%. The impact energy after maximum load has increased significantly with all flexible interphase incremental weight ratios.
Optimal Control of an Unmanned Lighter-Than-Air Vehicle Through Way-Point Navigation
Authors: Atmeh Ghassan M. , Subbarao Kamesh
Published: October 2013

The work presented in this paper deals with designing two, optimal, Linear-Quadratic controllers that are capable of navigating an airship through a series of planar waypoints. Two guidance laws are considered, a track-specific guidance law and a proportional navigation guidance law. Each provides commands to their corresponding controller based on vehicle and waypoint positions. A novel implementation of the extended Kalman filter (EKF) provides the required states and wind speed estimates to enhance the performance of the track-specific guidance law in the presence of wind disturbance.
Modeling and Simulation of Gas Turbine System on a Virtual Test Bed (VTB)
Authors: Thirunavukarasu Eshwarprasad , Fang Ruixian , Khan Jamil A. , Dougal Roger
Published: October 2013

Gas Turbine is a complex system and highly non linear in its overall performance. In order to study its impact on electric power quality under various load conditions, it is essential to create a high quality performance model of gas turbine to simulate its behavior in real time efficiently. This paper focuses on dynamic modeling of generic gas turbine model using alternate simulation environment for better feasibility. The model is developed on a virtual test bed which is an advanced dynamic simulation environment and can run a dynamic co-simulation effectively. The approach is by developing mathematical models of individual components of gas turbines and utilizing component performance map matching method to run the simulation. The paper discusses briefly about the VTB simulation environment and its use for dynamic modeling of gas turbine. The simulation studies carried out include design condition, off design condition and transient conditions. Working model of twin shaft turbine engine using compressor and turbine maps are validated with established gas turbine simulation software and results are shown.
Engine Life Evaluation Based on a Probabilistic Approach
Authors: Daroogheh Najmeh , Vatani Ameneh , Gholamhossein Maryam , Khorasani K.
Published: October 2013

In this paper Fouling and Erosion damages as two main sources of deterioration in the engine performance are modelled for a single spool engine. The effects of these phenomena on the Low Cycle Fatigue (LCF) and Creep status of the engine turbine blades are studied. A Matlab/Simulink model is developed for the LCF and Creep damages evaluation based on the available measured outputs. Several simulations are performed to investigate the effects of different levels of the Fouling and the Erosion degradations on the LCF and Creep damages propagation in the take-off mode of the flight. The probability of failure is calculated in each simulation scenario according to the Weibull distribution. The obtained results can be used as a prognostic tool to predict an appropriate next cycle for the engine maintenance schedule.
Prediction of the Jet Engine Performance Deterioration
Authors: Gholamhossein Maryam , Vatani Ameneh , Daroogheh Najmeh , Khorasani K.
Published: October 2013

This paper deals with performance deterioration modelling of a single spool gas turbine engine based on time-series methods. Towards this end, two univariate and multivariate methods, namely the Autoregressive Integrated Moving Average (ARIMA) and the Vector Autoregressive (VAR) schemes are applied to predict the Turbine Entry Temperature (TET) evolution during the flight cycles for maintenance purposes. In the VAR scheme, two engine process parameters i.e. the Turbine Entry Temperature (TET) and the Compressor Temperature are employed to achieve this prediction goal. The results show that employing multivariate modelling methods lead to better prediction horizons. For each method two scenarios are considered to demonstrate the effectiveness of the models.
Deterioration Detection and Health Monitoring in Aircraft Jet Engines
Authors: Daroogheh N. , Baniamerian A. , Nayyeri H. , Khorasani K.
Published: October 2013

In this paper the problem of jet engine deterioration detection and health monitoring is investigated by utilizing two methods. The first method is based on the fusion of the modified CUSUM (CUmulative SUM) method with the differential analysis approach. An enhanced differential analysis method is developed through which the degradation is captured from the unsymmetrical performance analysis of both engines on an aircraft. This is achieved by considering the effects of minor maintenance actions that are not reported. In the second approach, a statistical method based on the Hotelling’s T2-test approach is utilized to detect gradual degradations in the engine performance. The performance of our proposed approaches is evaluated by implementing them on a dual spool engine model that is developed by using the GSP software.
A Device for Performing Controlled Cutting Operations
Authors: Phan Andrew M. , Parmigiani John P.
Published: October 2013

Cutting operations using blades appear in several different industries such as food processing, surgical operations, gardening equipment, and so forth. Many practitioners of cutting operations will notice that it is easier to cut something by pressing and slicing at the same time versus doing each motion individually. They will also notice that certain angles or certain blade geometries make it easier to cut certain materials. As our society continues to increase our technological prowess, there is an ongoing need to better understand the underlying causes of simple tasks such as cutting so that cutting operations can be performed with more precision and accuracy than ever before. For many applications it is not possible to achieve the most optimum cutting force, cutting angle, and push to slice ratio and a compromise must be made in order to ensure the functionality of a cutting device. A means of objectively and efficiently evaluating cutting media is needed in order to determine the optimum parameters such as cutting force, cutting angle, and push to slice ratio for certain applications. The approach taken in this work is to create a testing apparatus that uses standard cutting media and performs controlled cutting operations to determine key parameters to specific cutting operations. Most devices used for performing experimental controlled cutting operations are limited to a single axis of motion, thus not incorporating the effect of the push to slice ratio. The device created and discussed in this paper is capable of performing controlled cutting operations with three axes of motion. It is capable of accurately controlling the depth of cut, push to slice ratio, and angle of cut in order to accurately capture motions seen in typical cutting operations. Each degree of freedom on the device is capable of withstanding up to 1550 N of cutting force while still capable of maintaining smooth motions. The device is capable of controlling the velocity of the push and slice motions up to 34 mm/s. Depth of cut, for both pushing and slicing, the reaction forces, and the angle of cut are all controlled and measured in real-time so that a correlation can be made between them. Data collected by this device will be used to investigate the effects of the push to slice ratio and angle of cut on cutting force and overall quality of cutting operations. Preliminary testing in wood test samples evaluates the effectiveness of the device in collecting cutting data. This device will also be used to validate several finite element analyses used in investigating cutting mechanics.
Static Testing of Compliant Plate Seals
Authors: Deo Hrishikesh V. , Trivedi Deepak
Published: October 2013

Self–correcting Compliant Plate Seals are being developed for various turbomachinery sealing applications including gas turbines, steam turbines, aircraft engines and oil & gas compressors. These seals consist of compliant plates attached to a stator in a circumferential fashion around the rotor. The compliant plates have a slot that extends radially inwards from the seal outer diameter, and an intermediate plate extends inwards into this slot from stator. This design is capable of providing passive hydrostatic feedback forces acting on the compliant plates that balance at a small tip–clearance. Due to this self–correcting behavior, this seal is capable of providing high differential pressure capability and low leakage within a limited axial span, and robust non–contact operation even in the presence of large rotor transients. In this paper we have described the testing of Compliant Plate Seals in a static leakage test rig (“shoebox” rig) to study the impact of different design parameters on leakage and vibration. A novel high–speed visualization set–up is described and the high–speed videos demonstrate robust non–contact operation for different assembly clearances, bridge–gaps and bridge–heights, for various differential pressure and pressure ratio conditions. The reported leakage results indicate that the leakage is relatively insensitive to assembly clearances due to the self–correcting behavior.
Curvature Effect Quantificaiton for In-Vivo IR Thermography
Authors: Cheng Tze-Yuan , Deng Daxiang , Herman Cila
Published: October 2013

Medical Infrared (IR) Imaging has become an important diagnostic tool over recent years. However, one underlying problem in medical diagnostics is associated with accurate quantification of body surface temperatures. This problem is caused by the artifacts induced by the curvature of objects, which leads to inaccurate temperature mapping and biased diagnostic results. Therefore, in our study, an experiment-based analysis is conducted to address the curvature effects toward the 3D temperature reconstruction of the IR thermography image. For quantification purposes, an isothermal copper plate with flat surface, and a cylindrical metal container filled with water are imaged. For the flat surface, the tilting angle measured from camera axis was varied incrementally from 0° to 60°, such that the effects of surface viewing angle and travel distance on the measured temperature can be explored. On the cylindrical curved surface, the points viewed from 0° to 90° with respect to the camera axis are simultaneously imaged at different temperature levels. The experimental data obtained for the flat surface indicate that both viewing angle and distance effects become noticeable for angles over 40°. The travel distance contributes a minor change when compared with viewing angle. The experimental results from the curved surface indicate that the curvature effect becomes pronounced when the viewing angle is larger than 60°. The measurement error on the curved surface is compared with the simulation using the non-dielectric model, and the normalized temperature difference relative to 0° viewing angle was analyzed at six temperature levels. These results indicate that the linear formula associated with directional emissivity is a reasonable approximation for the measurement error, and the normalized error curves change consistently with viewing angle at various temperatures. Therefore, the analysis in this study implies that the directional emissivity based on the non-dielectric model can be applied for the calibration of measurement error. The normalized error curve serves as a consistent basis to correct the measurement error due to curvature artifacts.
Nanoscale Fluid-Structure Interactions in Cytoplasm During Freezing
Authors: Ozcelikkale Altug , Han Bumsoo
Published: October 2013

In this study, a theoretical model is developed to simulate the biophysical events in the intracellular spaces considering the biphasic, i.e., poroelastic, behavior of the cytoplasm. Most previous studies in the cryobiology literature have modeled the biophysical response of cells to freezing assuming the spatial homogeneity of all physical properties within the intracellular space without considering fluid-structure interaction in both the intracellular and extracellular spaces. However, a few recent studies strongly indicate that spatial heterogeneity in the intracellular space occurs during freezing. We thus model the cytoplasm as a poroelastic material considering nanoscale fluid-structure interaction between the cytoskeleton and cytosol, and the effects of hierarchical fluid-structure interaction across the cell during freezing.
Post-Fire Mechanical Properties and Hardness of 5083 and 6082 Aluminum Alloys
Authors: Summers P. T. , Matulich R. D. , Case Scott W. , Lattimer Brian
Published: October 2013

Aluminum alloys are being increasingly used in lightweight transportation applications such as naval vessels and passenger rail. The primary aluminum alloys considered are Al-Mg (5xxx) and Al-Mg-Si (6xxx) due to their mechanical strength, corrosion resistance, and weldability. A major concern in the use of aluminum alloys for lightweight structural applications is fire exposure. Aluminum mechanical properties begin to significantly degrade at temperatures above 300°C. After fire exposure, structural integrity will be governed by the residual, post-fire strength of the aluminum. However, scarce data is available regarding the post-fire mechanical response.

The post-fire mechanical properties were characterized for several aluminum alloys: 5083-H116, 6082-T651 plate, and 6082-T6 extrusion. The alloys were exposed to elevated temperatures in a furnace to simulate a fire environment. Tension tests were performed to determine the mechanical response of the alloys. Vickers hardness measurements were also performed on specimens exposed for varying durations and temperatures to quantify the time and temperature-dependent behavior. The observed behaviors were explained in relation to the microstructural strengthening mechanisms for each alloy. Correlations were developed between the mechanical properties and Vickers hardness indentations.
Thermochemical Compatibility and Optical Properties of Gd2Zr2O7 and YSZ for Thermal Barrier Coatings
Authors: Wang Li , Zhang Peigen , Habibi M. H. , Guo S. M. , Eldridge Jeffrey I.
Published: October 2013

In this paper, the phase stability of 50wt% gadolinium zirconate (Gd2Zr2O7, GZ) and 50wt% yttria-stabilized zirconia (YSZ) powder mixture heat treated at 1300 °C for different time was investigation by X-ray diffraction (XRD). Results showed that due to the gadolinium and yttria ion diffusion, the lattice parameter of GZ decreased with increase of the heat treatment time, and a part of YSZ had phase transformation which might be one of the reasons for the interface failure in double-layered or functionally gradient TBC systems. In addition, the room-temperature hemispherical reflectance, transmittance and absorptance spectra over the wavelength range from 0.8 to 15 μm were also determined for free standing GZ, YSZ and 50wt% GZ+50wt% YSZ plasma sprayed coatings. All of the ceramic coatings are semitransparent due to the high transmittance in the wavelength range <6 μm where turbine engine thermal radiation is concentrated. GZ is transparent to longer wavelengths than 8YSZ and has unique small peaks at wavelength 2.4 μm. The mixed coating is intermediate in behavior to GZ and YSZ coatings.
Stiffness Characteristics of Membrane Space Structures Supported by Booms
Authors: Tamaru H. , Akita T. , Natori M. C. , Yamakawa H.
Published: October 2013

A systematic parametric study on the stiffness characteristics of compound space structures consisted of membranes and booms is presented. Using a tension field finite element code including membrane wrinkle effects, basic vibration characteristics of a square planar membrane structures are shown, and the effects of various conditions of applied tension between membrane and boom elements are discussed.
Influence of Shot Peening Parameters on Process Effectiveness
Authors: Elbella Abdalla , Fadul Fawaz , Uddanda Sri Harsha , Kasarla Nagender Reddy
Published: October 2013

The shot peening process is known for the surface treatment of metallic components. The process is used to enhance surface strength and extend component fatigue life by introducing a compressive residual stress pattern in the surface layers of the component. Numerical simulation of the shot peening process is a tool that has been recently used to help control the process. The simulation helps in investigating the effects of the process parameters with an aim of attaining the optimum residual stress profile and maximum process gain. In this paper, elasto-plastic finite element simulation is used to perform this investigative analysis. The process parameters that are varied in this analysis are: the shot diameter, shot velocity, incidence angle and target material. The analysis is to be carried for three different materials, namely, steel, aluminum and titanium. An Explicit commercial finite element code (ABAQUS) is used to simulate the impact phenomenon. The results of the analysis are sets of varying plots of residual stress through the depth of the targets.
Skill Level Differences of Urushi Craftspeople in Urushi Products
Authors: Shimode Yutaro , Endo Atsushi , Narita Chieko , Takai Yuka , Goto Akihiko , Hamada Hiroyuki
Published: October 2013

There are various traditional crafts in Japan. Japanese modern manufacturing industries have stemmed from the traditional crafts. And there is craftspeople’s wisdom in the traditional crafts technique inherited for years, which is well known as “tacit knowledge”. Especially in Kyoto which has 1200 years history, many traditional crafts have been inherited. In this study, Urushi crafts was focused.

Japanese lacquer is called “Urushi” in Japanese. Urushi have meanings such as Urushi tree, its resin and also Urushi crafts. Urushi has been used 9000 years ago in Japan. In this long history, Urushi crafts techniques have been developed, refined and inherited by many Urushi craftspeople. As a result, Urushi affect Japanese culture and aesthetic feeling greatly. Urushi has been viewed as special, and admired as black with the highest grade. Therefore, the Japanese word “Shikkoku” has been generated, inhere, “Shi” means Urushi, and “Kkoku” means black color.

Urushi has various characteristics. For example, Urushi coating surface is very smooth and glossy. It is considered that these characteristics are influenced by skill level of craftspeople. Then this study aims to analyze a difference between expert craftspeople and non-expert craftspeople in the painting process of Urushi. Body and eye motion between expert and non-expert craftspeople were analyzed and compared. As a result, there were differences in the time of painting with brush. And more there were differences in eye movement. It is considered that these differences were due to the difference of skill level, and in turn, the quality of Urushi products has been influenced.
Modeling and Experimental Evaluation of Monocrystalline Piezoelectric Materials for Electromechanical Actuation
Authors: Shetty Devdas , Campana Claudio , Nazaryan Nikolay
Published: October 2013

A great amount of research is being conducted to incorporate smart material actuators in aerospace applications such as (1) turbo fan engines (2) servo flap actuators for helicopter rotor control. For example, a piezoelectric stack actuator, coupled with mechanical or hydraulic amplification could provide the actuation required for the variable pitch fan system with a potentially higher level of reliability. In addition, piezoelectric actuation system could do so at a lower overall weight. However, there are limitations with existing piezoelectric stack actuators relative to power requirements in high load applications, resulting heat that is generated due to resistance and internal friction within the piezoelectric materials currently being utilized. Therefore, a new approach has been investigated to improve these characteristics in order for piezoelectric stacks to be a feasible solution for these types of large scale applications. A new configuration involving dielectric, conductor, piezoelectric material in a particular sequence of stack actuation is examined and experimented. This configuration is recommended due to the advantage that the metallic layers will allow creating the equipotential surfaces of the quartz and dielectric layers. This circumstance is very important because, in this case, it will take place instantly changing the electric potential of the surface of the piezoelectric material and the dielectric when the force or voltage applied to the actuator changes instantly. A nonlinear lumped parameter model of a piezoelectric stack has been developed to describe the behavior for the purpose of control actuation analysis.