bluuebunny/crossref_metadata_2025 huggingface dataset:
The Decline of Design Across the Curriculum
Authors: Mountain Jeffrey R.
Published: July 2009

Design across the curriculum has been a cornerstone of mechanical engineering education for well over a decade. The movement was an attempt to balance the tendency of most programs to over-emphasize engineering science. Over the course of that decade, many public universities have undergone a 7%–10% reduction in the number of credits required for graduation; usually in response to legislative pressure or competitive market conditions. In some instances, these reductions were not reflected in the general education content. Although the number of technical electives within the curriculum may have been reduced, seldom have they been completely omitted. Engineering science is considered the analytical foundation upon which new knowledge and engineering design are based. In addition, new frontiers in mechatronics, nanotechnology and alternative energy sources are becoming “must teach” subjects so that the discipline can evolve. The indication is that the “Design Across the Curriculum” concept either is, or will soon be in decline. This paper will present some historical perspective, a small sample of both common “solutions,” and a few unique approaches for maintaining design across the curriculum. The primary objective, however, is to initiate a dialog among engineering educators to begin to address the balance between engineering science and engineering design.
Fracture Toughness of Titanium - Titanium Nitride Multi-Layer Thin Film
Authors: Manoharan Mohan Prasad , Desai Amit , Haque Amanul
Published: July 2009

Thin film specimens of titanium - titanium nitride multilayer erosion resistant coating were prepared using liftout technique in Focused Ion Beam - Scanning Electron Microscope (SEM). The fracture toughness of the thin film specimen was measured in situ using a cantilever bending experiment in SEM to be 11.33 MPa/m0.5, twice as much as conventional TiN coatings. Ti–TiN multi-layer coatings are part of a new class of advanced erosion resistant coatings and this paper discusses an experimental technique to measure the fracture toughness of these coatings.
Fabrication and Characterization of Biologically Inspired Mushroom-Shaped Elastomer Microfiber Arrays
Authors: Kim Seok , Sitti Metin
Published: July 2009

This paper reports enhanced adhesion and friction of biologically inspired mushroom-shaped elastomer microfibers which are fabricated using micromolding and the notching effect during deep reactive ion etching (DRIE). The fabrication approach of this work allows mushroom-shaped small diameter fibers down to 100s of nanometer scale (using interference lithography) with high uniformity, and high yield in large area. The fabricated microfiber arrays demonstrate approximately up to 17 time higher adhesion and around twice higher static friction than the nonfibrillar flat elastomer surface on a 6 mm diameter glass hemisphere. Moreover, adhesion experiments with the microfiber arrays which have different thickness backing layers reveal the significance of the backing layer thickness on adhesion of the fiber arrays on smooth contact surfaces.
Ontology-Based Approach to Transform Fatigue Properties of Branched Sheet Metal Products for Use in Algorithm-Based Product Development
Authors: Hirsch Nils , Birkhofer Herbert , Landersheim Volker , Hanselka Holger , Gu¨nther Ute , Martin Alexander
Published: July 2009

In order to shorten the design process of a multi-chambered profile, it is important to integrate the Technological Findings of the production and the evaluation of the manufactured product in a structured and systematic way, providing mathematical optimization. The development of profiles exposed to cyclic mechanical loading has to take into consideration their fatigue properties. This paper proposes a classification structure of the existing Technological Findings of Linear Flow Splitting and the continuous manufacturing line. The classification is realized by an ontology, modeling the manufacturing processes, machines, the geometry of the semi-finished product, sub-processes, engaged machine components and specific conditions for the employed material. A profile manufactured by linear flow splitting is subject to severe changes of local material properties. This affects the fatigue properties of the profile. The paper focuses on preparing the integration of these fatigue properties in a simplified approach into the mathematical optimization. The approach is developed by modeling examples of profiles with different material properties by methods of mathematical optimization. The examples are applied to a numerical fatigue evaluation. Results and conclusions drawn of this analysis are incorporated in the ontology as data and rules, serving as an input for the optimization.
A Comprehensive Method to Assess the Ride Comfort of Vehicle
Authors: Mastinu G. , Gobbi M. , Pennati M.
Published: July 2009

The paper presents a comprehensive method for objective vehicle ride comfort evaluation. The method is based both on a validated mathematical model of a human seated on board of a road vehicle and on a dummy reproducing the human whole body vibrations (WBV). The first part of the research includes experimental tests on instrumented seats for evaluating the stiffness and the damping of respectively the cushion and the backrest. Either an indoor vibrating table fitted with a vehicle seat and different instrumented vehicles (cars and light trucks) running on a test track have been used. The test track includes uneven road and obstacles. Human subjects have been chosen in order to obtain a high variability in the anthropometric features (height, weight, gender, age). Several tests have been also performed with the same subject submitted to the same excitation in order to investigate the intra-subject variability. During the study different seats have been compared. From the acquired data, a mathematical model of the human subject has been derived and numerically validated by minimizing the error between the measured and the computed accelerations. The model is able to predict the dynamic response of a seated human and can be used for the optimal design of seats or for seat evaluation purposes. A mechanical device corresponding to the model has been employed. The device (MaRiCo) is fully adjustable in order to simulate the vibrational behaviour of different human subjects. Particular attention has been devoted to the construction of the dummy to reduce as much as possible the friction between the moving components. The dummy rests on the seat by means of special elements that act as the tights and the back of a human subject. A numerical validation has been performed by means of the dummy.
Polymer Coated Tin Oxide Nanowires for Improved Sensitivity of MEMS Chemical Sensors Based on Microbeams
Authors: Zielke Mark A. , Morrill Andrew , Demartini Barry , Moskovits Martin , Turner Kimberly
Published: July 2009

MEMS mass sensors are an important field of study for chemical and biological sensing. We utilize the massive surface area to volume ratio of tin oxide nanowires to improve the sensing characteristics of resonant cantilever gas sensors. The nanowires are grown onto released silicon cantilevers via the vapor liquid solid method, a type of chemical vapor deposition. Through intelligent catalyst placement the nanowires are grown selectively onto predefined surfaces of the cantilever. The increased surface area of our nanowire coatings provides greatly increased active binding area for analytes, while high quality factors are still achieved with this method. Our experiments actively monitor the removal of a silane self assembled monolayer from the sensor surface. Current nanowire coated sensors show a tenfold increase in sensitivity when compared to the bare sensors. We have functionalized the nanowires with a variety of polymer coatings. These functionalized sensors also show a substantial increase in sensitivity to the analytes. By varying the polymer coating applied to the nanowires, a sensor array can be generated that achieves gas recognition while having incorporated the increased sensitivity of the nanowire coatings.
Life Cycle Inventory Study of Biologically Inspired Self-Cleaning Surfaces
Authors: Raibeck Laura , Reap John , Bras Bert
Published: July 2009

In this paper, self-cleaning surfaces are investigated as an environmentally benign design option. These surfaces are a biologically inspired concept; first discovered on the lotus plant, micro- and nano-scale surface features aid in contaminant removal. Self-cleaning surfaces have been successfully recreated for engineering applications and appear on a variety of products. Because they can be cleaned with water alone, the use of such a surface could lead to less resource consumption during cleaning, if used in place of more resource intensive current industrial cleaning methods. A screening Life Cycle Inventory (LCI) study is used to determine if environmental benefits are obvious from the use of a self-cleaning surface over the entire life cycle. The study is performed on a chemical self-cleaning coating, selected for its durability, transparency and ease of use. The results of the LCI study are compared to current industrial cleaning practices of aqueous spray or ultrasonic cleaning, including solvent production and use of the cleaning machines. The LCI study reveals that environmental benefits are present in the use (cleaning) phase of a self-cleaning surface. However, when also considering the production of the self-cleaning surface, no clear environmentally superior choice exists. More analysis and evaluation of the production of self-cleaning surfaces is needed to select the more sustainable choice.
An Optimization Approach/Technique for Solving Graph Based Design Problems
Authors: Patel Jay , Campbell Matthew I.
Published: July 2009

This paper discusses a new topological optimization technique to solve graph based engineering design problems by decoupling parameters and topology changes. Using this approach optimal solutions are synthesized in the form of graph topologies for engineering problems. Currently we have successfully applied it to routing problems, resistive networks, neural networks, and sheet metal. This final problem has proven the most challenging but the results are not only novel and manufacturable but also satisfy multiple objective functions such as material cost and manufacturability. This paper presents Topological and Parametric Tune and Prune (TP2) as the first topology optimization method that has been developed specifically for domains representable by a graph grammar schema. The method is stochastic and incorporates distinct phases for modifying the topologies and modifying parameters stored within topologies. Thus far, with the problems that been tested, (TP2) had proven better than genetic algorithm in terms of the quality of solutions and time taken to acquire them.
Generative Design and CNC Fabrication Using Shape Grammars
Authors: Ertelt Christoph , Shea Kristina
Published: July 2009

Generative design and fabrication refers to the ability to autonomously generate designs while simultaneously generating all information to directly fabricate them. This technique is driven by the increasing need to rapidly and flexibly fabricate customized parts and individually designed products. For the automation of the design-to-fabrication process chain, intensive and dynamically updated knowledge from the domains of design and fabrication must be provided. To allow for a flexible, autonomous fabrication, the knowledge modeled must dynamically reflect the state of the fabrication system and its capabilities. This paper presents an approach to unify knowledge for generative design and generative fabrication using shape grammars. With shape grammars, the geometry of designs and their mapping to removal volumes corresponding to fabrication processes on CNC machine tools are represented. The process instructions for fabrication are included by augmenting the removal volume shapes with labels. A new shape grammar approach to represent designs and fabrication processes is presented and validated on an example functional part as a proof-of-concept. The approach enables pushing knowledge downstream, from design and process planning directly to the fabrication system itself providing a stepping stone towards awareness of machine capabilities in fabrication systems and autonomous process planning for customized parts.
An Introduction to VitalS
Authors: MacDonald John , Turner Cameron J. , Nekimken Howard , Evans Max , Moya Joey
Published: July 2009

VitalS is a system or methodology for evaluating the health or state of a variety of systems. Important or critical components of a system are identified and assigned weights based on how critical they are. Data are collected for each of these parameters, and the resulting data are analyzed using the VitalS to produce an indication of the system’s health or state. Component problems are readily identified using this technique. Various examples of VitalS are given in this paper. Examples included are medical, automobile, and avionic systems. The discussions includes introduction, utility and application of VitalS.
Product Realization in the Age of Mass Collaboration
Authors: Panchal Jitesh H. , Fathianathan Meryvn
Published: July 2009

There has been a recent emergence of communities working together in large numbers to develop new products, services, and systems. Collaboration at such scales, referred to as mass collaboration, has resulted in various robust products including Linux and Wikipedia. Companies are also beginning to utilize the power of mass collaboration to foster innovation at various levels. Business models based on mass collaboration are also emerging. Such an environment of mass collaboration brings about significant opportunities and challenges for designing next generation products. The objectives in this paper are to discuss these recent developments in the context of engineering design and to identify new research challenges. The recent trends in mass collaboration are discussed and the impacts of these trends on product realization processes are presented. Traditional collaborative product realization is distinguished from mass collaborative product realization. Finally, the open research issues for successful implementation of mass collaborative product realization are discussed.
Using Video Training Lectures in a Mechanical Engineering Computer-Aided Design Course
Authors: McGrann Roy T. R.
Published: July 2009

The primary objective of the Computer-Aided Engineering (CAE) course that is a required course during the third year in the mechanical engineering curriculum at Binghamton University is to educate students in engineering design. The benefits and limitations of computer-aided engineering design are stressed. Pro/Engineer® is used as the basis of this course. It integrates solid modeling, motion analysis, and finite element analysis. As a means to the objective of teaching engineering design, students must first be trained to use the software. The effectiveness of the software training and design education was assessed using a project that is repeated (although modified) each time the course is offered. This is often referred to as a “marker assignment.” The marker assignment in this case is an aircraft landing gear design and analysis. In this paper, the effectiveness of training videos for design education is examined using the marker assignment approach. Data for three semesters is used. In each semester a different method of presentation was used: (1) traditional in class lectures only, (2) only recorded videos distributed to students, and (3) recorded videos distributed to students combined with summary in-class lectures. The changes to the course that were adopted based on the assessment are presented. In addition, the results of a survey of student satisfaction with the video format used in the course are presented.
An Augmented Reality-Based Approach for the Visual Analysis of Intelligent Mechatronic Systems
Authors: Radkowski Rafael , Waßmann Helene
Published: July 2009

In this paper we present an approach for the visual analysis of intelligent mechatronic systems during an experiment. Intelligent mechatronic systems are denoted by the term self-optimizing systems. Such systems often are embedded systems or use software-agents for control, which act autonomously during operation. These operations are invisible for the engineers. According to this, it is difficult to understand why the system acts in a certain way. We use Augmented Reality to visualize the behavior of the system by showing sensor information, the states of the system, or the simulated parts, of a system under development. Using visualization, engineers can analyse the behavior during the experiment. The approach was tested in the project Neue Bahntechnik Paderborn.
Metric for Disassembly and Reuse Decisions: Formulation and Validation
Authors: Pandey Vijitashwa , Thurston Deborah
Published: July 2009

Design for disassembly and reuse focuses on developing methods to minimize difficulty in disassembly for maintenance or reuse. These methods can gain substantially if the relationship between component attributes (material mix, ease of disassembly etc.) and their likelihood of reuse or disposal is understood. For products already in the marketplace, a feedback approach that evaluates willingness of manufacturers or customers (decision makers) to reuse a component can reveal how attributes of a component affect reuse decisions. This paper introduces some metrics and combines them with ones proposed in literature into a measure that captures the overall value of a decision made by the decision makers. The premise is that the decision makers would choose a decision that has the maximum value. Four decisions are considered regarding a component’s fate after recovery ranging from direct reuse to disposal. A method on the lines of discrete choice theory is utilized that uses maximum likelihood estimates to determine the parameters that define the value function. The maximum likelihood method can take inputs from actual decisions made by the decision makers to assess the value function. This function can be used to determine the likelihood that the component takes a certain path (one of the four decisions), taking as input its attributes, which can facilitate long range planning and also help determine ways reuse decisions can be influenced.
Self Management in a Control Architecture for Parallel Kinematic Robots
Authors: Maaß Jochen , Steiner Jens , Amado Ana , Huhn Michaela , Raatz Annika , Hesselbach Ju¨rgen
Published: July 2009

Maintainability, extendibility and reusability of components in the design of robot control architectures is a major challenge. Parallel kinematic robots feature a wide variety of structures and applications. They are subject to easy reconfiguration because of the passive structure limbs. This class of robots requires more extensive calculations in their control laws than serial manipulators. During complex motion tasks, such as the ones required in assembly sequences, the algorithmic load may also vary over time. However, no generic control approach exists in order to reduce the complexity of control design for these kind of robots. In this paper the authors introduce an architecture for handling and assembly applications featuring self-management techniques as an approach to tackle these problems. The existing architecture features a modular and layered design. Concepts of self-management and self-optimization applied to this architecture are outlined. These properties are realized by the integration of self-managers within crucial system components. The mechanisms are extended for a future distributed version of the architecture. Real-time properties are guaranteed by an online formal analysis that verifies planned adaptations before realizing them.
Adaptive Servo Controller Design in an Optical Trap
Authors: Wulff Kurt D. , Cole Daniel G. , Clark Robert L.
Published: July 2009

Optical traps are an important tool in biophysics, which are capable of measuring forces on the the order of piconewtons and displacements on the order of nanometers. When being used as a probe, objects confined in optical traps are subjected to a broad-band thermal noise source known as Brownian motion. Closed loop control offers a method for reducing the magnitude of these disturbances, but controller design is a difficult and time consuming process. Even after a controller has been constructed, changes in the trapping power or changes between particles will change the plant dynamics and ultimately affect how well the controller performs. For these reasons, presented here is a method of designing an adaptive controller which automatically identifies the plant and actuator dynamics and designs a corresponding controller for disturbance rejection. The controller design is easily implemented on any digital control system.
A Centralized 5-RSP Parallel Mechanism
Authors: Rodriguez-Leal Ernesto , Dai Jian S. , Pennock Gordon R.
Published: July 2009

This paper presents a new class of parallel mechanism which is constructed with a 5-limb RSP architecture. To provide insight into the geometry and the position analysis of this mechanism, the paper presents closed-form solutions to the inverse and forward kinematic problems. Then the Kutzbach mobility criterion is used to show that the platform of the 5-RSP mechanism has a single degree of freedom. A mobility analysis based on the reciprocal constraint and motion sets of screws shows that the platform exhibits a screw motion, that is, a translation along and a rotation about the screw axis. The ratio of the translation to the rotation (referred to as the instantaneous pitch of the screw) is shown to be a function of the platform position. The screw axis is perpendicular to the base of the mechanism for all positions of the platform and passes through the centroids of the base and the platform. The attractive features of centralization are the simple design, and the wide range of possibilities for the pitch of the screw motion of the platform. Finally, the paper presents geometrical conditions that result in the pure translation of the platform; i.e., the rotational degree-of-freedom is eliminated.
Transformation Facilitators: A Quantitative Analysis of Reconfigurable Products and Their Characteristics
Authors: Weaver Jason M. , Wood Kristin L. , Jensen Dan
Published: July 2009

Products that transform into multiple states give access to greater flexibility and functionality in a single system. These “transformers” capture the imagination and can be elegant, compact, and convenient. Mechanical transformers are usually designed ad hoc; a methodology specifically aimed at creating transformation processes would help the designer better understand when to use transformation and how to best seize its advantages and avoid its pitfalls. There is an underlying common basis of principles and facilitators (e.g. Fold, Share Core Structure, Segment) that describes transformation processes. We conducted an empirical study of 190 reconfigurable products across several domains, observing the overall trends in how transformation occurs. We confirmed the consistent use of similar principles and facilitators across the design space, and we quantitatively determined the extent of correlation among them. This paper lays out characteristics and interactions that are popular in current transformer design, as well as opportunities for innovation in new directions. A case study is also presented that illustrates how these results can be used in the future to help develop a step-by-step methodology for generating concepts of transforming products.
Genome Reconfiguration of Metamorphic Manipulators Based on Lie Group Theory
Authors: Zhang Liping , Dai Jian S.
Published: July 2009

This paper investigates reconfiguration which was induced by topology change as a typical character of metamorphic mechanisms in a way analogous to the concept of genome varation in biological study. Genome is the full complement of genetic information that an organism inherits from its parents, espercially the set of genes they carry. Genome variation is to study the change and variation of this complement with genetic information and genes connectivity and is analogous to mechanisms reconfiguration of metamorphic mechanisms. Metamorphic mechanisms with reconfigurable topology are usually changing their configurations and varying mobility in accordance with different sub-working phase functions. The built-in spatial biological modules are for the first time compiled and introduced in this paper based on metamorphic building blocks in the form of metamorphic cells and associated inside break-down parts as the metamorphic genes for metamorphic bio-modeling as genome. The gene sequencing labels the genetic structure composition principle of the metamorphic manipulators. The bio-inspired mechanism configuration evolution is further introduced in this paper motivated by biological concept to metamorphic characteristics as different sub-phase working mechanisms gradually change and develop into different forms in a particular situation and over a period of time, as an evolutionary process of topological change that takes place over several motion phases during which a taxonomic group of organisms showing the change of their physical characteristics. Moreover, the proposed genetic structure composition principle in metamorphic manipulators leads to the development of module evolution and genetic operations based on the displacement subgroup algebraic properties of the Lie group theory. The topology transformations can further be simulated for configuration evolution and depicted with the genetic growth and degeneration in the living nature. Genome sequential reconfiguration for metamorphic manipulators promises to be mapped from degenerating the source generator to multiple sub-phase configurations. Evolution design illustrations are given to demonstrate the concept and principles.
Optimum Design of a Compliant Uniaxial Accelerometer
Authors: Desrochers Simon , Angeles Jorge , Pasini Damiano
Published: July 2009

This work focuses on the multi-objective optimization of a compliant-mechanism accelerometer. The method is used to optimally design an accelerometer with the architecture of a novel version of the Sarrus mechanism. The purpose is to maximize the sensitivity of the accelerometer in its sensing direction, while minimizing its sensitivity in all other directions. The paper starts with a brief description of the dynamics model of the compliant mechanism, followed by the formulation of the a posteriori multi-objective optimization. By using the normalized constrained method, an evenly distribution of the Pareto frontier is found. The paper also provides several optimum solutions on a Pareto plot, as well as the CAD model of the selected solution.
Design of a Heat Removal Method for the Electronics in Lithium-Ion Cordless Power Tools
Authors: Dibelka Jessica , Steimer Mark , Twomey Julianna , Traub Laura , Glancey James , Phillips Steven , Woods Sam
Published: July 2009

Cordless power drills are currently being designed with lithium-ion battery technology to produce more power per unit mass as compared to legacy nickel-cadmium battery packs. With this increase in power, more complex heat removal solutions are needed to dissipate heat resulting from electrical circuit resistance and insure electronic components, specifically the metal oxide semiconductor field effect transistor (MOSFET), will remain below its maximum operating temperature of 175°C. Heat spreaders, ventilation methods, and heat sinks were considered, with a newly designed heat sink being determined to be the most effective solution that met performance, manufacturing and cost requirements. Finite element models of the heats sinks along with models of the natural convection within the drill were developed and used to determine geometry and material requirements. Laboratory tests were performed on several prototype heat sinks and drills to validate the thermal modeling and ensure designs would meet the required performance metrics. From testing, it was seen that the new design absorbed the required amount of heat, keeping the MOSFET and handle temperature at 88°C. This insures the durability of the tool, keeping the temperature below the plastic deformation temperature of the drill handle. From the modeling and testing of this solution, a new design methodology was created and validated to expedite design iterations for future drill models and other cordless tool products.
A MDA Approach for Product Data Quality Throughout Vaccine Product Lifecycle
Authors: Moalla Ne´jib , Bouras Abdelaziz , Ouzrout Yacine , Neubert Gilles
Published: July 2009

Data quality is widely considered as a very serious problem for the majority of companies due to the specificities of each business context and the lack of adapted solutions. We present in this paper the benefits of a Model-Driven Architecture (MDA) in ensuring the interconnection of different business contexts’ specifications by providing a linked structure of models. This enables to generate bridges that connect implementations in different platforms. In this way, the systems interoperability can be satisfied throughout product lifecycle. The MDA approach is widely considered as a methodology for software generation from models, with a focus on enterprise and business models. Deploying a MDA approach in the supply chain context of vaccine industry allows us to deal with product data quality. In fact, it helps to translate some business models at a computer independent model through the MDA framework to generate a newly data model as well as some business rules and recommendations helping to communicate data models. To ensure the quality of product data in the Enterprise Resource Planning (ERP), the new generated data model is compared with the one of the ERP and proposed mapping rules are structured through a data reference model. Finally, three levels of reference frames are proposed to ensure the share and the traceability of generated metadata in order to ensure the evolution of defined models and preserve product data quality throughout its lifecycle.
Design of a Hydraulic Hose and Electric Cable Storage System for Mobile Agricultural Equipment
Authors: Mabel Sarah , Erickson Doug , Shannon Dan , Collins Sean , Glancey James , Smith Kevin
Published: July 2009

A new device for storing hydraulic hoses and electrical cables on round hay balers and other agricultural equipment has been designed and validated through computer modeling and prototype testing. The apparatus is a moveable steel arm assembly supported by an over center gas spring – linkage system that allows the device to toggle between an operational and storage (or transport) position. A face-grid feature allows the hoses a free range of motion, and insures that hoses remain organized. A full-scale prototype was constructed in order to confirm concept functionality, and determine key dimensions. Extensive calculations, computer modeling, and finite element analysis were utilized to optimize all components of the final design, and insure that the final manufacturing cost metric of $30 per unit would be met. Following these calculations, a second-generation prototype was constructed and field-tested with end users to ensure that the device met all performance requirements, while still maintaining ease of use. This device provides round baler users a trouble free hose storage and organization system that is convenient, efficient, easily manufactured and will improve equipment lifespan by promoting correct hose storage and cleanliness.
Overview of Remaining Useful Life Methodologies
Authors: Bagul Yogesh G. , Zeid Ibrahim , Kamarthi Sagar V.
Published: July 2009

Nowadays, it is imperative for products to function properly each time they are used. If a product fails during its use, it may have disastrous consequences. Estimating remaining useful life (RUL) of a product is a key to prevent such disasters, improve its reliability, provide security and reduce maintenance and operational cost. Naturally, estimation of RUL of a product and develop methodologies for the same is proving an interesting domain for researchers. This paper gives an overview of RUL estimation methodologies applied to various products. It also discusses hybrid methodologies which improve RUL estimation accuracy and overcome limitations of the individual methodologies. As this is an emerging area, these methodologies have been applied to only a handful of products. A list of these products is provided with references. A quantitative metric that measures the relative important characteristic differences among different methodologies is given. This paper concludes with few important points observed during literature review.
Pricing Remanufactured Products Under Stochastic Demand and Backlogging
Authors: Vadde Srikanth , Kamarthi Sagar , Zeid Ibrahim
Published: July 2009

Independent and small scale product recovery facilities (PRFs) often struggle to achieve profits under inconsistent inflows of discarded products and varying demand patterns for remanufactured products. Inconsistent inflows coupled with the varying demand cause undue fluctuations in inventory levels and holding costs. PRFs can leverage the inventory levels by posting appropriate prices for remanufactured products and procuring the right quantity of discarded products. This work determines the optimal prices of remanufactured products and the optimal procurement quantity of discarded products when (a) PRFs passively accept and proactively acquire discarded products, (b) demand for remanufactured products is stochastic, and (c) backlogging of demand is permitted. The stochastic demand is modeled to consist of an additive random variable. Optimal solutions are established when the additive random variable follows a generic probability distribution.
An Industrial Trial of a Set-Based Approach to Collaborative Design
Authors: Madhavan Kaarthic , Shahan David , Seepersad Carolyn C. , Hlavinka Danny A. , Benson Walt
Published: July 2009

A set-based multiscale and multidisciplinary design method has been proposed in which distributed designers manage interdependencies by exchanging targets and Pareto sets of solutions. Prior research has shown that the set-based method (SBM) has the potential to reduce the number of costly iterations between design teams, relative to centralized optimization approaches, while expanding the variety of high-quality, system-wide solutions. These results have been obtained with representative examples in a laboratory setting. The goal of this research is to investigate whether similar results are obtained from an industrial trial, implemented in an industry design environment. The SBM is applied to the design of a downhole module for our industrial partners at Schlumberger, a developer of oilfield tools and services. The design was conducted on location at Schlumberger by an intern who converted the existing Schlumberger design process into a set-based design process. Results indicate that the SBM delivers the benefits predicted in the laboratory, along with a host of advantageous side effects, such as a library of back-up design options for future design projects.
Examining Design Tool Use in Engineering Curriculum: A Case Study
Authors: Miller W. Stuart , Teegavarapu Sudhakar , Summers Joshua D.
Published: July 2009

This case study observes the effect of design tool use in engineering courses on subsequent uses of design tools. Students gain a familiarity with design tools as they use them in early engineering classes, and will traditionally implement similar methods to seek future design solutions. Problems arise because design tools are often used inappropriately, which may or may not lead to productive outcomes. Understanding how design tools are incorporated into engineering curriculum will reveal how that particular method was selected, the background information given to the student to facilitate tool use, and the benefit gained from using the specific tool in the given case. This information is valuable to the evaluation of the engineering curriculum of which few performance metrics exist. This case study utilizes a design team enrolled in a capstone design course to collect data on the use of design tools throughout their curriculum. Trends are revealed that relate how the tool use is implemented, how the instruction is delivered to the student, and the beneficial application of those to the given design project. These trends directly apply to the intellectual growth of the student as well as the topical coverage and implementation by the engineering department. Using this information, the engineering curriculum can improve its delivery of design instruction. It can be assumed that by improving the curriculum, the quality of the students will follow; yielding engineers who can study better and conduct design projects with intentional precision.
Designing a Lunar Wheel
Authors: Stowe David , Conger Kyle , Summers Joshua D. , Joseph Paul , Thompson Bart , Matthews Jaret
Published: July 2009

Given NASA’s renewed initiative to return to the moon, it is imperative to develop a mobility platform which will enable a wider range of exploration and science. To this end a wheel which can perform in a lunar environment for an extended period of time and distance is needed. This paper analyzes and evaluates the attempts to develop such a solution and the challenges which have arisen. Furthermore, it builds upon an analytical basis for the proposed solution and examines further applications in vehicular mobility. Specifically, three concepts were conceived, analyzed, prototyped, and tested in a senior design project class supported by NASA’s Jet Propulsion Laboratory and Michelin Tire Corporation, then critically examined for failure modes. The lessons learned from the analysis are currently being applied in the development of third and fourth generation prototypes.
Enhanced Multi-Agent Normal Sampling Technique for Global Optimization
Authors: Saremi Alireza , Birjandi Amir H. , Wang G. Gary , ElMekkawy Tarek , Bibeau Eric
Published: July 2009

This paper describes an enhanced version of a new global optimization method, Multi-Agent Normal Sampling Technique (MANST) described in reference [1]. Each agent in MANST includes a number of points that sample around the mean point with a certain standard deviation. In each step the point with the minimum value in the agent is chosen as the center point for the next step normal sampling. Then the chosen points of all agents are compared to each other and agents receive a certain share of the resources for the next step according to their lowest mean function value at the current step. The performance of all agents is periodically evaluated and a specific number of agents who show no promising achievements are deleted; new agents are generated in the proximity of those promising agents. This process continues until the agents converge to the global optimum. MANST is a standalone global optimization technique and does not require equations or knowledge about the objective function. The unique feature of this method in comparison with other global optimization methods is its dynamic normal distribution search. This work presents our recent research in enhancing MANST to handle variable boundaries and constraints. Moreover, a lean group sampling approach is implemented to prevent sampling in the same region for different agents. The overall capability and efficiency of the MANST has been improved as a result in the newer version. The enhanced MANST is highly competitive with other stochastic methods such as Genetic Algorithm (GA). In most of the test cases, the performance of the MANST is significantly higher than the Matlab™ GA Toolbox.
Shape Optimization of Potentially Slender Structures
Authors: Jorabchi Kavous , Danczyk Joshua , Suresh Krishnan
Published: July 2009

Shape optimization lies at the heart of modern engineering design. Through shape optimization, computers can, in theory, ‘synthesize’ engineering artifacts in a fully automated fashion. However, a serious limitation today is that the evolving geometry (during optimization) may become slender, i.e., beam or plate-like. Under such circumstances, modern 3-D computational methods, such as finite element analysis (FEA), will fail miserably, and so will the shape optimization process. Indeed, the recommended method for analyzing slender artifacts is to replace them with 1-D beams/ 2-D plates, prior to discretization and computational analysis, a process referred to as geometric dimensional reduction. Unfortunately explicit geometric reduction is impractical and hard to automate during optimization since one cannot predict a priori when an artifact will become slender. In this paper, we develop an implicit dimensional reduction method where the reduction is achieved through an algebraic process. The proposed method of reduction is computationally equivalent to explicit geometric reduction for comparable computational cost. However, the proposed method can be easily automated and integrated within a shape optimization process, and standard off-the-shelf 3-D finite element packages can be used to implement the proposed methodology.
Optimal Design of Product Family Throughout Commonalization, Customization and Lineup Arrangement
Authors: Fujita Kikuo , Akai Ryota
Published: July 2009

Product family design is a framework for effectively and efficiently meeting with spread customers’ needs by sharing components or modules across a series of products. This paper systematizes product family design toward its extension to throughout consideration of commonalization, customization and lineup arrangement under the optimal design paradigm. That is, commonalization is viewed as the operation that restricts the feasible region by fixing a set of design variables related to commonalized components or modules against later customization and final lineup offered to customers. Customization is viewed as the operation that arranges lineup by adjusting another set of design variables related to reserved freedom for customers’ needs. Their mutual and bi-directional relationships must be a matter of optimal design. This paper discusses the mathematical fundamentals of optimal product family design throughout commonalization, customization and lineup arrangement under active set strategy, and demonstrates a case study with a design problem of centrifugal compressors for showing the meaning of throughout optimal design.
A Deterministic Lagrangian-Based Global Optimization Approach for Large Scale Decomposable Problems
Authors: Khajavirad Aida , Michalek Jeremy J.
Published: July 2009

We propose a deterministic approach for global optimization of large-scale nonconvex quasiseparable problems encountered frequently in engineering systems design, such as multidisciplinary design optimization and product family optimization applications. Our branch and bound-based approach applies Lagrangian decomposition to 1) generate tight lower bounds by exploiting the structure of the problem and 2) enable parallel computing of subsystems and the use of efficient dual methods for computing lower bounds. We apply the approach to the product family optimization problem and in particular to a family of universal electric motors with a fixed platform configuration taken from the literature. Results show that the Lagrangian bounds are much tighter than convex underestimating bounds used in commercial software, and the proposed lower bounding scheme shows encouraging efficiency and scalability, enabling solution of large, highly nonlinear problems that cause difficulty for existing solvers. The deterministic approach also provides lower bounds on the global optimum, eliminating uncertainty of solution quality produced by popular applications of stochastic and local solvers. For instance, our results demonstrate that prior product family optimization results reported in the literature obtained via stochastic and local approaches are suboptimal, and application of our global approach improves solution quality by about 10%. The proposed method provides a promising scalable approach for global optimization of large-scale systems-design problems.
Enhanced Collaborative Optimization: A Decomposition-Based Method for Multidisciplinary Design
Authors: Roth Brian D. , Kroo Ilan M.
Published: July 2009

Astute choices made early in the design process provide the best opportunity for reducing the life cycle cost of a new product. Optimal decisions require reasonably detailed disciplinary analyses, which pose coordination challenges. These types of complex multidisciplinary problems are best addressed through the use of decomposition-based methods, several of which have recently been developed. Two of these methods are collaborative optimization (CO) and analytical target cascading (ATC). CO was conceived in 1994 in response to multidisciplinary design needs in the aerospace industry. Recent progress has led to an updated version, enhanced collaborative optimization (ECO), that is introduced in this paper. ECO addresses many of the computational challenges inherent in CO, yielding significant computational savings and more robust solutions. ATC was formalized in 2000 to address needs in the automotive industry. While ATC was originally developed for object-based decomposition, it is also applicable to multidisciplinary design problems. In this paper, both methods are applied to a set of test cases. The goal is to introduce the ECO methodology by comparing and contrasting it with ATC, a method familiar within the mechanical engineering design community. Comparison of ECO and ATC is not intended to establish the computational superiority of either method. Rather, these two methods are compared as a means of highlighting several promising approaches to the coordination of distributed design problems.
Minimum-Gap Evaluation Model for Multi-Constraint in One Dimension
Authors: Kuo Chang-Hsin , Tsai Jhy-Cherng
Published: July 2009

The gap between components in an assembly refers to the performance of the assembly. While variation of the gap is associated with tolerancing specifications of components, it is an important issue to investigate the limits of the gap between corresponding components. In this work, we treat the minimum gap gmin, the dominant dimension for a multiconstraint assembly in one dimension, as an index related to the performance of the assembly. We then propose a calculation method for finding the minimum gap, when fitting conditions of linear dimensions are linearly independent. If the fitting conditions are not linear independent, we will find an independent probability distribution function which is defined to conform to all the other fitting conditions. Finally, an evaluation model for multi-constraint in one dimension, similar to the idea of Taguchi loss function, is proposed with an illustration. The assembled state of an assembly with multiconstraint in one dimension thus can be evaluated based on the model and calculation method proposed in this paper. By comparing the minimum gap, the assembly with least clearance is then identified.
Direct 3D Layer Metal Deposition and Toolpath Generation
Authors: Ruan Jianzhong , Tang Lie , Sparks Todd E. , Landers Robert G. , Liou Frank
Published: July 2009

Multi-axis slicing for solid freeform fabrication (SFF) manufacturing process can yield non-uniform thickness layers, or 3-D layers. Using the traditional parallel layer construction approach to build such a layer leads to a staircase which requires machining or other post processing to form the desired shape. This paper presents a direct 3-D layer deposition approach. This approach uses an empirical model to predict the layer thickness based on experimental data. The toolpath between layers is not parallel; instead, it follows the final shape of the designed geometry and the distance between the toolpath in the adjacent layers varies at different locations. Directly depositing a 3-D layer not only eliminates the staircase effect, but also improves the manufacturing efficiency by shortening the deposition and machining times. A single track deposition experiment has demonstrated these advantages. Thus, it is a beneficial addition to the traditional parallel deposition method.