bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and Potential Application of Small Scale Wave Energy Converter
Authors: Aderinto Tunde O. , Haces-Fernandez Francisco , Li Hua
Published: January 2018

Although theoretical available wave energy is higher than most of ocean energy sources, the commercial utilization of wave energy is much slower than other ocean energy sources. The difficulty of integration with the electrical grid system and the challenges of the installation, operation and maintenance of large energy generation and transmission systems are the major reasons. Even though there are successfully tested models of wave energy converters, the fact that wave energy is directly affected by wave height and wave period makes the actual wave energy output with high variation and difficult to be predicted. And most of the previous studies on wave energy and its utilization have focused on the large scale energy production that can be integrated into a power grid system. In this paper, the authors identify and discuss stand-alone wave energy converter systems and facilities that are not connected to the electricity grid with focus on small scale wave energy systems as potential source of energy. For the proper identification, qualification and quantification of wave energy resource potential, wave properties such as wave height and period need to be characterized. This is used to properly determine and predict the probability of the occurrence of these wave properties at particular locations, which enables the choice of product design, installation, operation and maintenance to effectively capture wave energy. Meanwhile, the present technologies available for wave energy converters can be limited by location (offshore, nearshore or shoreline). Therefore, the potential applications of small scale stand-alone wave energy converter are influenced by the demand, location of the need and the appropriate technology to meet the identified needs. The paper discusses the identification of wave energy resource potentials, the location and appropriate technology suitable for small scale wave energy converter. Two simplified wave energy converter designs are created and simulated under real wave condition in order to estimate the energy production of each design.
Performance/Cost Assessment of a Variable Frequency Drive (VFD) Control Applied to a Brazilian Long Pipeline
Authors: Federico Heitor Honda , Bassetto Izeds , Módica José Eduardo
Published: January 2018

All through the last decade, the Brazilian pipeline industry has invested heavily in controlling long pipeline’s inventory, leak detection systems and in energy efficiency, the latter being object of study of this paper. A sensitive area to such investments can be perceived in the efforts made to control the energy supply to pumping stations. Nevertheless, one can clearly observe the weight of tradition pending over Brazilian projects resulting in a tendency toward the use of control valves as means of pump controlling. This solution is generally believed to be simpler, more reliable and less costly than the common alternatives. Still and all, as the Brazilian pipeline industry modernizes its facilities and procedures, particularly due to economic and environmental concerns, new strategies for traditional problems are considered and assessed in engineering projects.

Throughout this paper, the authors assess one such project in which the engineering staff chose to apply a variable frequency drive (VFD) instead of the traditional process automated control valve. The company that operates the system made available the necessary process data and project parameters in order to conduct a thorough assessment both from the financial and the technical points of view. Hydraulic data as well as electrical motor parameters were made available to this research as well as a yearlong worth of process instrumentation data. Brazil has a long history investing and developing technology to replace gasoline for ethanol as automotive fuel. The pumps studied, located at the city of Ribeirão Preto, are responsible for pushing ethanol through a pipeline all the way to the Refinery of Paulínia, delivering fuel to be consumed in São Paulo’s metropolitan area, the most populated location in the country. As a basis of comparison, the authors estimated the capital and operational expenditure as well as the energy consumption of a fictional control valve system for the same pipeline and then put them against actual data made available by the company.

As a conclusion, the paper brings to light that, although variable frequency drive systems indeed demand a higher capital expenditure, when the operational costs are considered, they can compensate that initial investment by presenting the facility with more energy efficient operation. Furthermore, after carefully assessing the provided data, the variable frequency drive seems to result in a more continuous and smooth operation maintaining a higher occupation rate of the pipeline. Suggestions are also proposed and assessed as a guide to further investments and operational procedure changes aiming at optimizing the company’s process.
Embedding the Innovation Process in the CDMIT: Mexican Engineers Face New Challenges Today
Authors: López-Parra Marcelo , Borja Vicente , Ramírez-Reivich Alejandro , Ricardo-Torres Osiris
Published: January 2018

Since 1976 the Mechanical Design Center of UNAM (CDMIT) has worked under the premise that experiential learning is a scheme that substantially helps in the task of educating engineers. The work of the CDMIT over the years has yielded good results that have underpinned the education process of its engineering students. Using real-world sponsored projects to integrate engineering knowledge taught in the classroom is not a novel idea though; CDMIT’s method of organizing teams of students essentially follows Kolb’s framework of learning through experience (LTE). The CDMIT implemented a way of bringing real-world engineering projects closer to the students, sometimes emulating such experiences in the classroom and some other times via the realization of senior capstone projects that involve the design and manufacture of automatic machine systems that are developed to either displace intensive manual work needed in production lines or to avoid importing expensive pieces of production equipment. This paper reports on the results and impact that these design projects and application of the LTE model have had on the students’ education. On the other hand, Mexico is also experiencing new opportunities and challenges; the country became the fourth world largest exporter of automobiles not long ago, in 2014. The automotive companies established in Mexico are mainly looking for engineers that have a generic and solid technical background in the core knowledge areas of the curriculum, this allows their training and development departments to better guide young engineers towards specific strategic technical fields that are considered important. The automotive industry boom, besides creating new job positions, has helped Mexico to come onboard the train of future transportation technologies. This trend has been particularly appealing to young engineers who envisage great business opportunities. Under this scenario, the LTE method has therefore to be strengthened in different ways. The second part of the paper explains how the CDMIT is embedding the innovation process in the curricula; the final goal is to help students learn the tools that will allow them to develop a design ability, emphasizing innovation and ingenuity.
Minimizing the Heat Transfer Effect on a Laser Robotic End of Arm Tooling During Manufacturing Process
Authors: Hamieh Abdallah , Jawad Badih , Liu Liping , Fernandez Vernon
Published: January 2018

Heat dissipation is considered as a challenging task in the manufacturing field. The main objective of this study is to design a new pressure wheel assembly of a laser weld system to maximize heat dissipation in order to endorse a better performance of the wheel and help achieve a long lasting cycle of life. In this study transient thermal and structural analysis of the pressure wheel is conducted by using ANSYS workbench. The work will examine the effects of geometrical parameters on the thermal performance of pressure wheel assembly during a period of time. Different design models and numerical simulations are performed in investigating the effects of geometrical holes and ventilated discs on the disk on the thermal performance, which include the shape, size, and distribution of pillar posts. The analysis will support the design process in monitoring different models in terms of performance, heat loss and manufacturing cost.

A comparison is made for three different designs and the best design is selected. The calculated results estimated in a period of time of 50 seconds show that the temperature drops with the 3rd design from T = 500 K to 453 K. Also under giving limitations the design with enhanced heat transfer has a better heat dissipation and the temperature decreases to T = 399 K. The present work will help improve the performance of pressure wheel in the welding industry by providing computational results for successive design testing and data validation.
Endwall Heat Transfer Enhancement Around Cylinders With a Wall-Mounted Vortex Generator Pair
Authors: Hussain Safeer , Liu Jian , Wang Lei , Sundén Bengt
Published: January 2018

Measurement of endwall heat transfer around a circular cylinder with a vortex generator pair has been investigated. Steady state liquid crystal thermography is adopted. Cylinders having two different height to diameter ratios have been employed. In one case, the cylinder has one end free in the flow and in the other case it has both ends attached on the walls. Local Nusselt numbers both upstream and downstream of the cylinder with and without the vortex generator pair are calculated. Nusselt numbers in streamwise and spanwise directions for both cases with vortex generator are compared with each other as well as with corresponding base cases. It is found from the experiments that the vortex generator influences the endwall heat transfer significantly downstream of the cylinder but has a small effect in the upstream region. Moreover, for different height to diameter ratio of the cylinder different heat transfer patterns are observed downstream of the cylinder. The vortex generator pair plays its major role on the endwall heat transfer enhancement in the spanwise direction and it expands as one moves from the upstream to downstream direction. To fully understand the advantage of the vortex generator pair, thermal performance is calculated for each case and it was found that in presence of the vortex generator pair, the cylinder with shorter height to diameter ratio shows higher thermal performance. Reynolds number dependence has also been investigated and it was found that the thermal performance decreases with increasing Reynolds number for both cases having a vortex generator pair.
Slung Load Amplification Detector
Authors: Hiremath Nandeesh , Shukla Dhwanil , Hale Emily , Sparacello Taylor , Komerath Narayanan
Published: January 2018

Externally slung loads and their mission applications are becoming more common on human and autonomously piloted air vehicles. Flight speed is often limited not by the performance envelope but by the danger of divergent load oscillations. Certifying this limiting speed for every load-vehicle combination, is a huge barrier to operations. The conservatism dictated by this uncertainty may itself be life-threatening in critical applications. Computing the dynamics of slung loads for a specific load/vehicle combination has been hindered by lack of knowledge on bluffbody aeromechanics. The prevailing top-down approach is to incorporate slung load aeromechanics calculations into large comprehensive aeromechanics codes for rotorcraft. We argue for a bottom-up approach. This allows on-the-fly system identification and dynamics simulation. The Slung Load Amplification Detector (SLAD) concept provides an on-board safety system to predict, detect, avoid and alleviate divergent oscillations. SLAD is based on a knowledge base derived from wind tunnel data and simulation results including canonical geometries, as well as practical shapes. Validation of simulation results against two practical test cases lends confidence. SLAD allows reliable distinction between pseudo and absolute divergence, permitting an increase of as much as 50% speed in safe flight speed, and guidance on active alleviation of oscillations.
Studies on Coal Ignition and Combustion Characteristics
Authors: Chen Xue , Gu MingYan , He XianHui , Yan Dan , Wang Jimin , Chu HuaQiang , Liu FengShan
Published: January 2018

A 2-D numerical model of flow, heat transfer, and combustion of coal particles in a laminar gas flow at O2/CO2 atmosphere was developed based on the Eulerian-Lagrangian methodology. The gas-phase combustion was modeled using the GRI-Mech 3.0. The motion of coal particles was simulated using a trajectory model. The model was employed to study the coal ignition time, temperature and mass changes. The effects of particle diameter, the flow temperature and oxygen concentration on the ignition time and the combustion characteristics of coal particles were also investigated. The results obtained show that smaller size particle experiences a shorter ignition time with a higher coal temperature. A higher gas temperature leads to a shorter coal particle ignition time; increasing the flow temperature the difference in the ignition time of different sized coal particles decreases. The coal particle ignition time is decreased when the oxygen concentration is increased.
Crystallinity-Induced Variation of the Yield Strength of Electroplated Copper Thin Films
Authors: Luo Yifan , Tei Kunio , Suzuki Ken , Miura Hideo
Published: January 2018

The quality of grains and grain boundaries of polycrystalline copper thin films was analyzed by using image quality (IQ) value obtained from the observed Kikuchi pattern by applying electron back-scatter diffraction (EBSD) analysis. It is considered that the IQ value strongly correlates with the order of atomic configuration in the observed area, in other words, density of various defects, and thus, the area with high IQ value was defined as the area with high crystallinity. The yield strength of a grain was measured by using micro tensile test system in a scanning electron microscope. A bicrystal structure which had two grains with different IQ values was cut from a copper thin film by using focus ion beam (FIB) and the sample was fixed to a single-crystalline silicon beam and a micro probe, respectively, by tungsten deposition. Finally it was thinned to 1μm and stretched to fracture at room temperature. In this micro tensile test, however, the tungsten deposition on the side surface of the test samples caused serious error on the measured strength. Therefore, in this study, the experimental method was improved by the development of an effective method for elimination the excess tungsten deposition. During the tensile test, a mass of plastic deformation and necking phenomenon were obviously observed. Ductile fracture always occurred in the grain with higher Schmidt factor. It was found that the yield strength of a copper grain decreased monotonically with the increase in the IQ value when the IQ value at the grain boundary was larger than 3500.
Acoustic Diagnostics Applications in the Study of the Oscillation Combustion in Lean Premixed Pre-Evaporation Combustor
Authors: Zhang Zilai , Zang Shusheng , Ge Bing , Sun Peifeng
Published: January 2018

The paper presents an experimental investigation of the thermoacoustic oscillations detection in a lean premixed pre-evaporation (LPP) combustor using acoustic signals. The LPP model combustion chamber oscillation combustion test platform was designed and built, and the combustion chamber oscillation combustion conditions of the sound - pressure - thermal parameters contrast experiment was complete. In this experiment, the thermal parameters signal, the acoustic signal and the dynamic pressure signal were collected under the oscillation state and the transition state (ignition condition, stable to the oscillation combustion condition, the oscillation to the stable combustion condition and the flameout condition), and been analyzed comparatively. The experimental result shows that the acoustic signal and pressure signal can reflect the changing of the main frequency in the combustion chamber. That is, at the same inlet air flow, the main frequency of the combustion chamber is proportional to the thermal load, while at the same fuel flow, the main frequency of the combustion chamber does not change with the changing of air flow. In addition, the frequency multiplication of the acoustic signal is more obvious than the pressure signal’s, which show that the interference of the acoustic signal is less, it can clearly reflect the thermoacoustic oscillation in the combustion chamber. In the transition state, the pulse energy of the acoustic signal is obviously increased after ignition. The main frequency energy increases when the working condition begins to change in the stable to the oscillation combustion condition. The main frequency energy decreases when the working condition begins to change in the oscillation to the stable combustion condition. During the flameout condition, the oscillating energy begins to decay from the high frequency region. For the acoustic signal is less disturbed than the pressure signal and it can obtained the same result with the pressure signal in the oscillation state and the transition state, it can replace the pressure signal in the thermoacoustic coupling oscillation analysis of the lean premixed pre-evaporation combustor the lean premixed pre-evaporation combustor.
Development of a Motorcycle Food Delivery System From an International Perspective
Authors: Vallee Glenn E. , Eheander Jonathan
Published: January 2018

An investment firm located in Peru has partnered with Western New England University to develop a novel, motorcycle mounted fast food delivery system for international markets. The project afforded students the opportunity to work on an international product development team, exposing them to the design requirements and constraints of international customers and companies. The often damp and cool climate in many countries makes food prone to becoming soggy during delivery as the moisture escaping from the hot food quickly fills the food containers and delivery box mounted to the back of the motorcycle, saturating the food. Delivery times, often in excess of 45 minutes, can also cause the food to become cold, resulting in decreased customer satisfaction, product returns and lost business.

The project was conducted over a three year period using nine mechanical engineering students. The project began in 2014 when a team of two students was tasked with developing a benchtop method of keeping food hot and preventing it from becoming soggy while being delivered. They determined that the use of ceramic heaters and small fans effectively kept the food warm and dry. In 2015, two teams of two students competed to develop a box design with integrated heaters and fans which could be powered using an alternator mounted to a delivery motorcycle. While effective fans and heating elements were found, it was decided that the mounting of an additional alternator was cumbersome and motorcycle dependent, rendering the concept poorly suited for field installations. In 2016 another team of two students integrated a hand-made lithium ion Battery pack and two 300W ceramic heaters and computer fans into a production delivery box. While the system maintained food quality for up to 50 minutes, the battery pack was unable to reliably provide the required power to the system. Finally, in the fall of 2016, a student improved this design by improving the heater and fan performance while adding urethane insulation into the box. Temperature was controlled using a commercially available thermistor, and all components were integrated into a retrofit kit which could be installed by a technician in the field. The power requirement was reduced by over 50% and the system operated for 110 minutes using two, commercially available 27 Ah lithium iron phosphate batteries.

Students gained global perspective of the product development process as they experienced the effects of various cultures on the requirements of customers and the international design and marketing team.
3D Printing a Bio-Polymer Cap for the Articular Femoral Condyles: A Feasibility Study
Authors: Olsen Luke , Wang Zhiyong
Published: January 2018

With approximately 12% of adults in the United States affected by osteoarthritis (OA), constant research is being performed to advance treatment techniques for this ailment. 3D printed bio-polymer caps have been proposed as a potential treatment for severe cases of OA, and are an alternative to traditional implants. This report considers the feasibility of one such bio-polymer cap using a simplified, linear, finite element analysis (FEA) model. Material properties for both Bionate 80A and articular cartilage are considered for comparison. The simulation modeled joint loading for a 195 lb, 867.4 N, adult male squatting from 0 to 90-degrees flexion with a mathematical model governing the changing contact area on the medial and lateral condyles. Menisci effects were neglected as a part of the model reduction. For Bionate 80A, minimum and maximum stress values of 1.124 MPa and 3.555 MPa were obtained, with corresponding deflections of 126.8 μm and 316.8 μm. The articular cartilage model gave stress values of 1.102 MPa and 3.623 MPa, with deflections of 170.2 μm and 420.8 μm. A maximum shear stress value of 1.988 MPa was obtained in the Bionate 80A simulation. From these results, it was determined that the Bionate cap is comparable to articular cartilage and could be a viable replacement in the cases of advanced OA, but the Bionate cap may have limitations on joint flexibility due to the relatively small 1.65 factor of safety at 90-degree. The maximum shear stress value indicates it would be viable to use specific biocompatible cements as a method of fixture.
Numerical Modeling of Crack Propagation in Human Aorta
Authors: Jayendiran Raja , Ruimi Annie
Published: January 2018

A 3D finite element model to predict the stress state and tear propagation on the human aorta is presented. The human aorta is modeled as a three-layered hyperelastic cylindrical shell with a radial tear in the intima layer and circumferential tear in the media layer. The ultimate strength and fracture energy required for the onset of crack propagation is obtained from the literature and used as an input to the simulations. The effect of depth and length of the tear on the critical pressure show that the critical pressure decreases when tear length and depth increase. The variation of von Mises stress on the aortic layers due to crack propagation is investigated. This study will provide additional insight into the mechanics of aortic dissection (AD) with the possibility of being used in designing new clinical protocols.
The Use of Dermestidae in Documenting Underbody Blast Injuries to Foot-Ankle-Leg Complex
Authors: Perry Brandon J. , Heltzel Sara B. , Salzar Robert S.
Published: January 2018

Conflicts in the Gulf have exposed warfighters to injury by means of improvised explosive device (IED) detonation beneath armored military vehicles, commonly referred to as underbody blast (UBB). Together with the pelvis, injuries to the foot-ankle-leg number among those most commonly sustained by warfighters in the event of a UBB. Multiple biomechanical tests are currently being conducted in order to develop injury thresholds and risk functions for warfighters subjected to these vertical loads. In a previous study of 38 foot-ankle-leg complexes tested under automotive and UBB load rates, a distribution of injuries was produced. High-speed x-ray video and post-test CT, Statscan (Lodox, Johannesburg, South Africa), and dissection were performed to document injuries. It is, however, difficult to thoroughly remove soft tissue and cartilage from the calcaneus and talus without inducing damage that could be mistaken as a test-induced injury. For this test series, Dermestidae macerated 31 tali and 18 calcanei revealing 12 and 4 injuries, respectively, that were previously undiagnosed through more traditional techniques. Logistic regressions were produced to quantify the significance of the findings. The pre- and post-maceration regressions predicted a 50% injury risk of 6626N and 4228N, respectively, or a 44% difference in mean.
Combined Effects of Variable Intake Manifold Length, Variable Valve Timing and Duration on the Performance of an Internal Combustion Engine
Authors: Sawant P. , Bari S.
Published: January 2018

Naturally aspirated internal combustion (IC) engines with a fixed intake assembly are generally tuned to produce an induction boost at a single engine speed by capitalizing the induction pressure waves only over a narrow speed range. This paper investigates the individual and combined effects of varying intake runner length and intake valve timing on the performance parameters of an IC engine at engine speeds from 3000 rpm to 9000 rpm. The 1-D model of the KTM SI engine built for simulations in Ricardo Wave software is validated with 98% accuracy against experimental test results. The performance parameters thus obtained, as a combined effect, show an average improvement of 7.02% throughout the engine’s speed range. With the co-existence of variable length intake runners and variable intake valve opening timing, the required number of variations to boost the engine performance are found to be reduced making variable intake assembly more feasible.
Micro-Contact Models for Metallic Line-Contact Based on Measured Surface Profile
Authors: Chen Jian , Hong Jun , Zhang Jinhua , Zhu Linbo , Liu Zhigang
Published: January 2018

In order to study the dry rough line-contact mechanism between two longitudinally rough metallic surfaces, the measured profile is mathematically described by quadratic functions for the application of the existing micro-contact models. The mechanical parameters are determined using the different approximating criteria. Next, based on these deterministic parameters, different micro-contact models are employed and extended to predict the characteristics of a line-contact. Comparison of different theoretical calculation results reveals that the greater maximum values of the contact deformation and the ratio of real to nominal contact area are predicted by the Hertz model as compared to the micro-contact models considering the elastoplastic deformation, and that the KE (Kogut and Etsion) and JG (Jackson and Green) models predict closer results. It is also found that when the rough surfaces are described by quadratic functions according to the same area criterion or same root mean square (RMS) criterion, the line-contact responses between them prescribed by any micro-contact models have the same tendency.
Analysis of Forming Limits in Biaxial and Dome Test
Authors: Nikhare Chetan P.
Published: January 2018

From centuries the metals and materials has been characterized using a traditional method called uniaxial tension test. The data acquired from this test found adequate for operations of simple forming where one axis stretching is dominant. Currently due to the demand of lightweight component production, multiple individual parts are eliminated by stamping in a single complex shape which further reduces many secondary operation. This need is driven by the requirement of 54 miles per gallon by 2025. Due to the complex part geometry, the forming method induces multi-axial stress states, which found difficult to predict using conventional tools. Thus to analyze these multi-axial stress states limiting dome height test and bulge test were recommended in many research. However, these tests limit the possibilities of applying multi-axial loading and resulting stress patterns due to contact surfaces. Thus a test machine called biaxial test is devised which would provide the capability to test the specimen in multi-axial stress states with varying load. In this paper, two processes, limiting dome test and biaxial test were modeled and compared. For this, the cruciform test specimens were used in biaxial test and conventional forming limit specimens for dome test. Variation of loadings were provided multi-axially in both test to capture the limit strain from uniaxial to equi-biaxial strain mode. In addition, the strain path, forming and formability was investigated and difference between the tests were provided.
90 Degree Impact Simulation of Steel Wheel
Authors: Gao Qian , Shan Yingchun , Liu Xiandong , Jiang Er
Published: January 2018

The wheel is one of the important safety components of the vehicle. So, it is required to pass the dynamic rotating bending test, the dynamic radial fatigue test and the impact test. The 90-degree impact test represents the driving performance of a vehicle when the vehicle drives through the road pits, or drives in other harsh conditions. As for the steel wheel, there are no mandatory requirements for the impact test. In recent years, some steel wheel enterprises bring up 90-degree impact test for steel wheels in order to ensure the quality of their products. In this paper, a finite element simulation model of the steel wheel impact test bed under the case of 90-degree was established according to an enterprise’s impact test requirement. The software “ABAQUS” was used to simulate the 90-degree impact test. A wheel / tire overall model was assembled, considering the impacts of tire inflation and the tire preloading process. Then the deformation state of the rim under 90-degree impact load was analyzed to predict whether it could pass the requirements of relevant impact test successfully. The results show that the steel wheel does not meet the requirements of the impact test, which makes it necessary to study the steel wheel’s impact test and optimize the structure of the rim. This paper also provides a reference method for the impact simulation of the steel wheel.
Environmental Impact of an Industrial Kitchen: A Case Study
Authors: Dai T. , Fleischer A. S. , Wemhoff A. P. , Lee R.
Published: January 2018

The large number of industrial kitchens and their energy-intense characteristics provides opportunities for pollution prevention. Life cycle assessment (LCA) is a proper tool not only for unitizing the environmental impact of the complex system of an industrial kitchen, but also for making environmental food labels for the foods produced in the same industrial kitchen. In this study, a gate-to-gate LCA of 11 types of food was conducted to evaluate the environmental impact of a typical industrial kitchen, Villanova University’s Donahue Hall. First, material and energy flow data, including cold storage, food preparation, food display, lighting, heating, ventilation, and air conditioning (HVAC), and dish washing were collected. This data, along with standard data on energy generation and transmission, were used in the LCA. The results show that global warming, fossil fuel depletion and ecotoxicity are the main environmental impact categories. Furthermore, HVAC, cold storage and cooking are the three largest contributors of environmental burden. Using the metrics developed, tuna salad, tomato soup and pasta are the most environmental friendly foods of the 11 sampled food types, while pizza and cheese quesadillas have the worst environmental performance. Energy saving measures for HVAC, cold storage and cooking are proposed.
Position Identification of Inclusions in Soft Objects by Indentation Testing
Authors: Shirai Yuki , Li Zhimeng , Sakuma Atsushi
Published: January 2018

The incidence rate of breast cancer for women in Japan is increasing each year. The three main methods of screening for breast cancer are finger palpation, mammography and breast ultrasound. These methods must be improved to decrease the incidence rate. This involves the development of personal, easy-to-use devices that facilitate cancer diagnosis. This study evaluates an indentation device developed to imitate traditional finger palpation and identify the position of the tumor inside the breast. The identification procedure is based on the extended Hertzian contact theory, which was developed to evaluate the elasticity of a thin specimen. In this extended theory, the thickness effect of the specimen is represented by a thickness parameter, and the position can be identified by the analysis of the effect. The procedure is verified by using FEM for ideal inclusion model in soft object, and the accurateness of the identification is discussed for the development. In the verification, some difference in the identified position between the condition and the result of FEM is observed with the difference of the identified elasticity of the object. It was reported that the approximation of accurate elasticity could affect the accuracy of position identification. Subsequently, the identification accuracy of Young’s modulus and thickness of specimen is discussed considering the problem of inclusion. Using the proposed approach, high accuracy can be observed in the range of 5 mm to 15 mm; however, a greater level of accuracy in identification remains to be achieved in other ranges. Thus, it is concluded that identification is possible using the extended Hertzian contact theory; however, for accurate identification of cancer position in a breast, the theory requires further modification.
BTIPS vs TRIZ: Comparison of the Approaches to the Teaching, Research and Practice of Conceptual Design
Authors: Bzymek Zbigniew M.
Published: January 2018

Two problem-solving methods are compared in this paper: BTIPS (Brief Theory of Inventive Problem Solving) and TRIZ (Teoriya Resheniya Isobratitielskich Zadatsh). BTIPS was derived from TRIZ and TIPS (Theory of Inventive Problem Solving). BTIPS is shorter than TRIZ as a procedure but at the same time is enriched in its contents. The general search for the Ideal Solution using BTIPS is simple and straight-forward. In BTIPS some new principles, features, effects and system components — that do not exist in TRIZ and TIPS — have been introduced. BTIPS also recommends the Axiomatic Design tests for the End Solution. This paper compares the two systems on the basis of opinions gathered through teaching and consulting practice. The application of the BTIPS method starts with a problem that has to be properly separated from the environment. The problem-solving approach presented in this paper includes a sequence of steps, definition of contradictions, a choice of solution modules, algorithms, and definitions of designed systems and subsystems. Recommendations for the proper search for the End Solution are given. The tests of an Ideal Solution’s effectiveness and economy are also suggested. Application examples and references to problem-solving practice are also given.
A Numerical Analysis Approach to Evaluate Hardness and Distortion for Selected Multi-Track Laser Cladding Configurations: P420 Steel Bead Deposition on Mild Steel
Authors: Nazemi Navid , Urbanic Ruth Jill
Published: January 2018

Laser cladding is a surface modification technique that is being explored as an additive manufacturing solution for metal. The laser cladding process is associated with nonuniform material strength within the clad and the heat-affected-zone. In addition, residual stress development increases the crack driving forces and reduces the fatigue life of the part. In the present work, a 3D transient fully coupled thermal-metallurgical-mechanical numerical model was built to simulate the coaxial powder injection laser cladding process for P420 stainless steel powder on an AISI 1018 steel plate for 50% +/− 10% bead overlap conditions. This work is an extension of prior physical and virtual simulation analyses. The model was employed to explore the effect of depositing directions and overlapping configurations on the temperature field evolution, thermal cycling characteristics, mechanical properties, and induced distortions in the clad and substrate. The model was validated by Vickers microhardness measurements and heat-affected-zone geometry from the specimens’ cross-sectioning. The simulation results show good agreement with experimental measurements with a 14% maximum error. It was found that the 50% bead overlap configuration with a raster fill deposition pattern had the most consistent hardness results, and minimal distortion. The presented simulation methodology can be used to predict the mechanical and physical properties of laser cladded components and to provide relevant information for process planning decisions.
Interfacial Fracture Behaviors of Single Particle Impacts During Aluminum Cold Spray Additive Manufacturing and Repair Process
Authors: Cavallaro Paul V. , Hulton Andrew W.
Published: January 2018

The current research represents a preliminary investigation of the cold spray metal deposition process which is a form of additive manufacturing and coating repair. It relates the deformations produced from a single particle impact with a substrate surface to the post-impact interfacial fracture behaviors resulting from separate globally applied mode-I and mode-II loadings. The particle and substrate materials were Al 5056 and Al 6061-T6, respectively. A description of the modeling process is presented and its inherent difficulties are discussed. A two-step numerical modeling process was pursued. First, the particle and substrate impact deformations were obtained using the strain rate-dependent Johnson-Cook Flow Stress Material Model for three particle velocities of interest. Second, the modes-I, II and III strain energy release rates (GI, GII, and GIII, respectively) were characterized along the curvilinear impact surfaces using linear-elastic fracture mechanics (LEFM). Crack initiation, crack growth and ultimate fracture loads of the particle-to-substrate interfaces were determined using the Virtual Crack Closure Technique (VCCT). The predicted results were compared for each particle velocity. The influence of mesh discretization, element distortions, interfacial contact surfaces, etc. are elaborated on for consideration in future modeling efforts. This research, in conjunction with future validation tests, is a fundamental step towards the numerical modeling of cold spray fracture behaviors across multiple material length scales; beginning with a single particle/substrate interface, extending to multiple particles and progressing towards the bulk material scale. Results of such models and experiments will identify specific cold spray processing parameters that may be optimized to improve the interface strengths and fracture resistance levels.
Development of a Computational Model to Visualize Air Flow Into Surrogate Ballistic Wounds
Authors: Ziadat John , Muci-Küchler Karim H.
Published: January 2018

In addition to the direct mechanical damage that takes place during a ballistic injury, the formation of the temporary wound cavity creates a suction effect capable of introducing debris, particles, and bacteria from the environment into the wound track. This introduction of bacterial contamination into the wound can give rise to infections which may delay healing or result in more serious problems. Various authors have conducted controlled ballistics experiments placing bacterial contamination on the surface of ballistics gelatin targets to study the effect of parameters such as projectile caliber and speed on the distribution of bacteria along the permanent cavity. The results reported in the literature showed that bacteria were present along the entire surrogate wound track. Understanding the contribution that the formation of the temporary cavity has on the number and distribution of bacteria along the surrogate wound requires the development of experiments to visualize the flow of air during the transient phase of target deformation and the use of numerical simulations to predict variables associated with the flow of air, like pressure-time histories along the projectile path, that cannot be directly measured during experiments.

This paper discusses the development of a finite element model using ANSYS Autodyn for the simulation of a small caliber projectile traveling at moderate speeds penetrating a soft tissue surrogate target made of ballistics gelatin. The model uses a Coupled Eulerian-Lagrangian formulation and discretization scheme, which allows for the analysis of not only the deformation of the solid bodies, but also of the flow of air into the wound track. For model validation, the numerical results are compared to spatial data extracted from high speed video recorded during experiments matching key model parameters. Comparisons of the numerical and experimental results indicate that the model is providing reasonable results for the deformations and overall air flow. The predicted pressure dynamics within the simulated wound track clearly suggest that areas of partial vacuum exist within the cavity, which is consistent with the suction effect mentioned by several researchers.
Force Control Method of Soft Actuator Using Multiple Super Elastic Alloy Wires
Authors: Aizawa Shun , Nozawa Taichi , Sakuma Atsushi
Published: January 2018

Super elastic alloy (SEA) has good flexibility with moderate rigidity and then is widely used in eyeglasses, bras and so on. SEA’s flexibility is based on the phase transformation between austenite and martensite structures of material metallurgy, and it is known that the transformation can be controlled by heating and cooling the material. The active deformation of SEA is already reported as controllable by the heating and cooling under pre-stressed condition, but it is known that the deformation is on / off control because the material has very strong nonlinearity in their stress-strain relationship. Then the development of smooth control of SEA’s active deformation is studied to realize soft actuator in this report. The smoothness of the control is realized by the multiplying the wires of SEA in actuating unit of 1DOF actuator. The theory of SEA controller is formulated by using the constitutive equation of the metallo-thermo-mechanics which represents the kinetics of phase transformation between austenite and martensite structures. The developed controller with the formulation is applied to actuate 1DOF actuator with multiple wires of SEA for the verification of the realization. The qualitatively match between theory and experimental results is observed here but quantitatively mismatch has occurred in this report. In the discussion of this paper, it is shown that the mismatch is occurred because the formulation is based on the ideal condition without the deformation of actuator unit. Then this report shows that it is important to design the soft actuator not only their actuating element but also the other elements which affect the deformation behavior of the actuator as a total unit.
Formation of Boundary Layer in the Flow of Shear-Dependent-Viscosity Fluids Between Parallel Plates
Authors: Ashrafi Nariman , Sadeghi Ali , Shafahi Mehdi
Published: January 2018

Formation of the boundary layer in the laminar flow of Herschel–Bulkley fluid between parallel plates is taken into consideration. In particular, the study is focused on the flow of the shear thinning and shear thickening fluids past a partial vertical wall in between the plates. Upon numerically solving the continuity and momentum equations the flow is analyzed throughout the domain using a finite volume scheme. The shear stress at the wall together with velocity distribution are evaluated and compared with experimental results for several values of Herschel-Bulkley coefficients for fluidity and flow behavior index.
Study of the Surface Roughness Evolution of Pinned Fatigue Cracks, and its Relation to Crack Pinning Duration and Crack Propagation Rate Between Pinning Points
Authors: Kelton Randall , Fathi Jalal , Meletis Efstathios I. , Huang Haiying
Published: January 2018

Changes in surface morphology have long been thought to be associated with crack propagation in materials. In this paper, we study the changes in the surface profile of the crack-tip plastic zone with an attempt to understand the relationship between the plasticity-induced surface profile changes and the crack growth behavior. Center crack specimens were electropolished and etched to reveal the grain structure for white light interferometer (WLI) imaging prior to and during fatigue testing. After growing the crack to a predetermined pre-crack length, a viewing zone was selected outside of the plastic zone of the pre-crack. The surface profile of the viewing zone was imaged using a WLI microscope at selected fatigue cycle intervals. An image processing algorithm was developed to evaluate the changes of the surface profile. We observed that the crack growth rate is not uniform at the microscopic scale; the crack growth was retarded at crack pinning points and the crack grows at a faster rate while propagating between the pinning points. Relatively large surface topology changes were observed to be constrained to the area surrounding the tip of pinned cracks. However, there was an avalanche of surface changes covering the entire monotonic zone upon the crack being released from a pinned location. Interestingly enough, minor or no measurable surface changes could be seen for propagating cracks. These results indicate a surface roughness change threshold may exist for predicting the duration during which a crack is pinned. Results suggest the threshold and crack propagation rate between pinning locations may be functions of the amplitude of the stress intensity factor.
A Review of Challenges in Integrating Robot and Motion Control Into a Single System
Authors: Unnikrishnan Nishant , Hull Kevin , Nicolson Edward
Published: January 2018

Automation industries are trying to integrate and consolidate the operation of various processes that make up their production line. Most often, every one of those processes is controlled by unique controllers and hardware as the process demands. Each of these independently controlled units can be seen as “islands of automation”. It is indeed a challenge for the control engineer to ensure smooth communication between these islands. The challenge gets magnified many fold when the plant performs troubleshooting, maintenance, or an upgrade. Compatibility over time, between components that make up the line can never be guaranteed in today’s world dominated by software drivers where improvements and upgrades are frequent. It is generally agreed in the industry that controllers and software consolidation should be done as much as possible. In this paper, the authors would like to discuss the case of integration of two such islands of automation, i.e. motion control (traditional single axis control of servos) and robotics. Automation integrators working on applications such as packaging, converting, palletizing etc. use a combination of robots and independently acting servos to achieve their objective. Programming software and programming methods for these two elements have been quite different. There has been a push in the automation industry to consolidate the control programming of motion components and robots because the underlying control techniques that actuate motion are the same. However, there are challenges that must be overcome in order to ensure that this push brings about useful and substantial changes that reduce control programming, maintaining and troubleshooting efforts. Such challenges are listed in this paper. Potential solutions to overcome these challenges are also laid out in this work.