bluuebunny/crossref_metadata_2025 huggingface dataset:
A Hybrid Relationship Modeling Scheme for Parametric Design Considering Uncertainties
Authors: Zhao Dong , Xue Deyi
Published: July 2009

This research introduces a new scheme to model different types of relationships in parametric design considering uncertainties. First a hybrid parameter relationship network is developed to associate the parameters through their relationships. In this hybrid parameter relationship network, in addition to the deterministic parameters and relationships, non-deterministic parameters (e.g., random parameters and fuzzy parameters) and non-deterministic relationships (e.g., neural network relationships and fuzzy relationships) can also be modeled. Propagation of parameter values and their uncertainties through this hybrid parameter relationship network is then investigated. Two optimization mechanisms, probability based design optimization and possibility based design optimization, are employed to identify the optimal design considering objective random uncertainties and subjective fuzzy uncertainties. A computer tool has been implemented and used for the optimal design of a solid oxide fuel cell (SOFC) system.
A Measure of the Information Loss for Inspection Point Reduction
Authors: Wa¨rmefjord Kristina , Carlson Johan S. , So¨derberg Rikard
Published: July 2009

Since the vehicle program in automotive industry gets more and more extensive, the costs related to inspection increase. Therefore, there are needs for more effective inspection preparation. In many situations, a large number of inspection points are measured, despite the fact that only a small subset of points is needed. A method, based on cluster analysis, for identifying redundant inspection points has earlier been successfully tested on industrial cases. Cluster analysis is used for grouping the variables into clusters, where the points in each cluster are highly correlated. From every cluster only one representing point is selected for inspection. In this paper the method is further developed and multiple linear regression is used for evaluating how much of the information that is lost when discarding an inspection point. The information loss can be quantified using an efficiency measure based on linear multiple regression, where the part of the variation in the discarded variables that can be explained by the remaining variables is calculated. This measure can be illustrated graphically and that helps to decide how many clusters that should be formed, i.e. how many inspection points that can be discarded.
Selecting Technology Alternatives for Product Families Through Technological Coverage and Functional Verification
Authors: Coatane´a Eric , Alizon Fabrice , Christophe Franc¸ois , Yannou Bernard
Published: July 2009

In product platform development the technology selection issue has seldom been studied. This article tries to fill this gap by introducing an original Technology Selection Method (TSM) to help designers to manage technology selection within the design of a product family. This method is based on technological coverage and functional verification, including the behaviour of the future product family. Practically, the proposed approach uses a multi-objective analysis based on dimensional analysis theory to choose the best technology available. The developed approach has three major points of interest. First, dimensional analysis theory is considered as a specific type of multi-objective optimisation approach which aggregates attributes using a weighting method based on the laws of physics. This manner of viewing dimensional analysis theory provides a scientific coherence to the weighting process which is not obtainable with other multi-objective methods. Second, the principle of similarity included in dimensional analysis theory is extended and allows a range of technologies and range of functions to be compared in a unique design space. Third, the dimensional analysis provides a powerful simulating tool for studying different kinds of behaviours and interactions between attributes. Consequently, dynamic aspects can be analysed and robustness analyses can be performed. The interest of such a method is highlighted through a case study involving a family of small excavators. We suggest that the potential scope of the approach is broad and our aim is to demonstrate the entire scope of the approach in future research.
Smart Material and Control Design for Vibration Suppression
Authors: Ting Yung , Yang Ci-Chun , Xu Je-Guan , Ho Bin-Kwan , Chen Shin-Liang , Li Chun-Chung
Published: July 2009

A smart material made by piezoelectric ceramics to have the function of both the sensor and actuator is developed for vibration suppression. Unlike the passive method that implements suitable components to modify the structural effect of equivalent mass, damping, or stiffness etc. under a known and defined condition, this smart material is designed with the capability of self-detecting and self-actuating so that it can actively damp variant changing vibrations. Interdigital electrode method is used to make the smart material in order to enhance the sensitivity and the piezoelectric strain effect for the sensor and actuator. Polarized electric field of the interdigital electrode influential to the performance is investigated in particular. Various smart materials and thickness affecting polarized electric field of the interdigital electrode is studied and evaluated by ANSYS analysis. Dynamic modeling by using finite element method and Hamilton theory is derived for both the sensor and actuator. Internal model control structure is used for vibration control design. Predictive control method based on finite-element dynamic modeling is developed. Moving optimization method is also used to deal with the uncertainties of the environment so that the robustness of the device is improved. Practical experiment is carried out for performance evaluation.
Engineering Changes During the Service Phase
Authors: Vianello Giovanna , Ahmed Saeema
Published: July 2009

This paper focuses upon understanding the characteristics of engineering changes, in particular changes that emerge during the service phase of complex products, and on how these changes can be related to the product development process. For this purpose, a set of engineering change reports from an aerospace engine has been analyzed and the findings have been compared with change documentation from drilling machinery for the oil industry. These findings give insights into which phases of the design process should be modified in order to reduce the number of change requests from the service phase and to enable designers to efficiently answer the unavoidable change requests. This can be used to improve the product development process in order to take into account the factors leading to changes.
Multi-Stage Design Method for Practical Compliant Mechanisms by Topology and Shape Optimizations and Shape Conversion Method Utilizing Level Set Method
Authors: Kobayashi Masakazu , Nishiwaki Shinji , Higashi Masatake
Published: July 2009

This paper proposes a multi-stage design method for a design of practical compliant mechanisms. The proposed method consists of topology and shape optimizations and a shape conversion method that incorporates two optimizations. In the 1st stage, an initial and conceptual compliant mechanism is created by topology optimization. In the 2nd stage, an initial model of shape optimization is created from the result of topology optimization by the shape conversion method based on the level set method. In the 3rd stage, the shape optimization yields a detailed shape of the compliant mechanism by considering non-linear deformation and stress concentration. Execution of the shape optimization after the topology optimization enables evaluation of stress concentration and large deformation effect that are normally difficult for the traditional topology optimization. On the other side, the precise conversion from the model by topology optimization to the one for the shape optimization becomes possible by the shape conversion method that is utilizing the level set method. Using the proposed multi-stage method, a practical compliant mechanism can be designed with the designer’s minimum efforts that are indications of design conditions of the topology and shape optimizations and several parameters and threshold values of the shape conversion method.
Port-Based Ontology Modeling for Product Conceptual Design
Authors: Cao Dongxing , Fu Ming Wang , Gu Yongmao , Jia Haipeng
Published: July 2009

Ontology has been known as an important means to represent design knowledge in product development, however, most ontology creation has not yet been systematically carried out. Port, as the location of intended interaction between a component and its enviornment, plays an important role in product conceptual design. It constitutes the interface of a component and defines its boundary. This paper introduces an approach, it is convenient to abstractly represent the intended exchange of signals, energy and/or material, and creat and manage port-based domain ontology, to port-based ontology modeling (PBOM) for product conceptual design. In this paper, port concept and port functional description through using natural language are first presented and their semantic synthesis is used to describe port ontology. Secondly, an ontology repository which contains the assorted primitive concepts and primitive knowledge to map the component connections and interactions is built. Meanwhile a model of port-based multi-views which contains functional view, behavior view and configuration view is articulated, and the attributes and taxonomy of ports in a hierarchy are presented. Next, a port-based ontology language (PBOL) is described to represent the process of port ontology refinement, and a port-based FBS modeling framework is constructed to describe system configuration. Furthermore, a formal knowledge framework to manage comprehensive knowledge is proposed, which could help designers create, edit, organize, represent and visualize product knowledge. Finally, a revised tape case is employed to validate the efficiency of the port ontology for product conceptual design and illustrate its application.
Finite Element Model Updating Approach to Damage Identification in Beams Using Particle Swarm Optimization
Authors: Saada Mohamed M. , Arafa Mustafa H. , Nassef Ashraf O.
Published: July 2009

The use of vibration-based techniques in damage identification has recently received considerable attention in many engineering disciplines. While various damage indicators have been proposed in the literature, those relying only on changes in the natural frequencies are quite appealing since these quantities can conveniently be acquired. Nevertheless, the use of natural frequencies in damage identification is faced with many obstacles, including insensitivity and non-uniqueness issues. The aim of this paper is to develop a viable damage identification scheme based only on changes in the natural frequencies and to attempt to overcome the challenges typically encountered. The proposed methodology relies on building a Finite Element Model (FEM) of the structure under investigation. A modified Particle Swarm Optimization (PSO) algorithm is proposed to facilitate updating the FEM in accordance with experimentally-determined natural frequencies in order to predict the damage location and extent. The method is tested on beam structures and was shown to be an effective tool for damage identification.
Knowledge Management for Fault Tree Analysis Based on Quantity Dimension Indexing
Authors: Murakami Tamotsu , Kikuchi Yosuke , Hiraoka Youji
Published: July 2009

In this paper, the authors propose computerized support for fault tree analysis (FTA) based on a new design knowledge management approach called quantity dimension indexing. FTA is a method of analyzing and visualizing the causes of fault events by expanding a fault event hierarchically to its possible cause events and constructing a tree diagram representing the entire structure of the problem. When a designer finds or encounters a problem during a product design and development process, an effective way of ensuring the security and safety of the product is to identify all the possible causes of the problem by FTA and fix them. Although FTA is an effective method, it is not easy for a designer to construct a complete fault tree without any misunderstanding or oversight. A promising approach for supporting FTA is to utilize a computerized knowledge management method. Although many knowledge management techniques for literal expression have been developed, they are not necessarily suitable for managing the engineering design knowledge of physical phenomena. To solve this problem, the authors propose a new design knowledge management approach called quantity dimension indexing and computerized support for FTA such as the verification of consistency of a fault tree and fault tree construction advice. By analyzing fault tree examples based on actual design activities in a company, the possible feasibility and future promise of the proposed approach are indicated.
PML in Application: An Example of Integral Sheet Metal Design With Higher Order Bifurcations
Authors: Anderl Reiner , Raßler Jochen , Rollmann Thomas , Wu Zhenyu
Published: July 2009

Processes are very important for the success within many business fields. They define the proper application of methods, technologies, tools, and company structures in order to reach business goals. Not only manufacturing processes have to be defined from the start point to their end, also other processes like product development processes need a proper description to gain success. For example in automotive industries complex product development processes are necessary and defined prior to product development. Over the last decades several product modeling languages have been developed moving to object oriented modeling languages, such as UML, but the used process modeling languages are still procedural. The paradigm shift caused by object oriented description within product modeling languages has to be transferred to process modeling languages. This paper describes an object oriented approach for process modeling, referred to as PML and its application to a complex product development and production process for integrated sheet metal design of higher order bifurcations. Using UML as a starting point an object oriented process modeling method is differentiated. The basic concepts which are needed for process modeling are put into an object oriented context and are explained. The paper gives an outlook, what can be achieved by the new approach.
Functional Part Families and Design Change for Mechanical Assemblies
Authors: Dabbeeru Madan Mohan , Mukerjee Amitabha
Published: July 2009

We consider two questions related to functional part families: a) how to characterize function in a computational framework, and b) how does the structure-to-function model generalize when the design changes, e.g. by changing the set of design variables? For the first, we observe that function is defined on the space of behaviours of the part, whereas structure is defined in the space of design parameters. For mechanical assemblies, as the design parameters change, their effect on the motion parameters can be complex, and cannot be automated in full generality. Thus, the mapping from structure-to-function involves considerable designer knowledge. For computational purposes, we quantify this function by defining part-family-specific Configuration Space (C-space) constructions, and also a metric that operates on these C-spaces to define each function. When the design is changed, either by changing the design space (structure), or by the user expectation (function), can existing design knowledge from the earlier part family migrate to the new product family? We make a start towards exploring how this knowledge can be modified when the part family is evolved, for example by introducing additional design variables, or by changing functional roles. Using examples from several lock designs, we present a small prototype for this process of modeling function and design change, implemented on a commercial CAD engine.
Integrating Assembly Design, Sequence Optimization, and Advanced Path Planning
Authors: Spensieri Domenico , Carlson Johan S. , Bohlin Robert , So¨derberg Rikard
Published: July 2009

Assembling a product is a delicate process at the borderline between design and manufacturing. Shortening the time between them plays a central role both for quality assurance and fast time to market. In this paper, we describe an automatic tool based on a new method, integrating assembly design, sequence optimization, and advanced rigid body path planning. First, we introduce a greedy algorithm for assembling a product, part by part, based on state-of-the-art path planning. We exploit all the six degrees of freedom of a rigid body to search for collision-free paths, instead of limited motions. Then, we use assembly design in order to limit the search for an optimal assembling sequence and to guarantee geometrical quality among the sequences examined. Disassembly path planning is used here to further cut the state space and to give a quality measure to the sequences. Eventually, we present results for an industrial test case, which has been successfully solved by applying our method.
Molecular Dynamics Analysis of Formation and Friction on Pattern Replication in Direct Nanoimprint
Authors: Sung Cheng-Kuo , Hsieh Chih-Wei
Published: July 2009

It is well known that metallic nanostructures can be potentially applied in many fields. Direct nanoimprint features an uncomplicated and efficient fabrication process of the metallic nanostructures. This paper contributes to the investigation of the formation and friction in direct nanoimprint process by utilizing molecular dynamics (MD) simulations. The MD model consists of a silicon mold and an aluminum thin film. For the formability, the phenomenon of springback and mold cavity filling ratio are investigated first under conditions of various imprinting depths and film thicknesses. For the friction, the friction mechanisms induced on the mold are studied subsequently. Since a nickel mold is adopted in many industrial applications, it is also simulated to compare with the silicon mold for the purpose of illustrating the material effect on friction mechanisms. This study explores not only friction mechanisms at different stages of the process but the friction force affected by various geometric configurations of the mold, for example, linewidth-to-pitch ratio and surface roughness. This work also provides the general concept that which force dominates the process force and what percentage of the friction force takes in the imprinting force.
A Pseudo-Rigid-Body Model for Spherical Mechanisms: The Kinematics and Stiffness of a Compliant Curved Beam
Authors: Leo´n Alejandro , Jagirdar Saurabh , Lusk Craig P.
Published: July 2009

A pseudo-rigid-body model (PRBM) which describes a class of curved compliant beams in terms of spherical mechanism kinematics was developed. The topology of the spherical compliant segment and its rigid-body equivalent were chosen to be analogous to planar models. The nomenclature for the spherical PRBM was also chosen to facilitate comparison with planar models. The motion of the compliant segment was calculated Finite Element Analysis and the PRBM parameters were determined. The characteristic radius and parametric angle coefficient were found to decrease as the angle subtended by the beam increases. The kinematic and elastic parameterization limits of the model increase with increasing beam angle. The stiffness of the beam is described by two separate spring elements, which describe the appropriate combination of moment and force which produces spherical motion. A previous planar PRBM is shown to be the small angle limit of the new spherical PRBM.
Optimal Model Selection of Suport Vector Classifiers for Rolling Element Bearings Fault Detection Using Statistical Time-Domain Features
Authors: Hameed Z. , Hong Y. S. , Cho Y. M. , Ahn S. H. , Song C. K.
Published: July 2009

Support Vector Machines (SVMs) are being used extensively now days in the arena of pattern recognition and regression analysis. It has become a good choice for machine learning both for supervised and unsupervised learning purposes. The SVM is primarily based on the mapping the data to a hyperplane using some kernel function and then increasing the margin between the hype planes so this hyperplane classifies the data in the normal and fault state. Due to large amount of input data, it is computationally cumbersome to yield the desired results in shortest possible time by using SVM. To overcome this difficulty in this work, we have employed statistical Time-Domain Features like Root Mean Square (RMS), Variance, Skewness and Kurtosis as pre-processors to the input raw data. Then various combinations of these time-domains signals and features have been used as inputs and their effects on the optimal model selection have been investigated thoroughly and optimal one has been suggested. The procedure presented here is computational less expensive otherwise to process the input data for model selection we may have to use super computer. The implementation of proposed method for machine learning is not much complicated and by using this procedure, an impending fault/abnormal behavior of the machine can be detected beforehand.
Exploring the Impact of Virtual and Physical Dissection Activities on Students’ Understanding of Engineering Design Principles
Authors: McKenna Ann F. , Chen Wei , Simpson Timothy W.
Published: July 2009

Product dissection has become a popular pedagogy for actively engaging engineering students in the classroom through practical hands-on experiences. Despite its numerous advantages, dissection of physical products has many drawbacks, including not only the costs required to start-up and maintain such activities but also the workspace and storage space needed for the products and tools used to dissect them. This paper presents results from on-going research that is investigating the extent to which dissection of virtual representations of products — what we refer to as virtual dissection — can be used in lieu of physical product dissection in the classroom. In particular, we found positive learning gains in students’ ability to identify and describe the function and production method of components contained in a hand-held power drill, for both physical and virtual dissection groups. However, the data also reveal differences in the overall maximum level attained as well as differences in the range and types of components identified between the groups. While we recognize that virtual dissection will never provide the same hands-on experiences as physical dissection, we contend that virtual dissection can be used effectively in the classroom to increase students’ understanding of engineering design principles. By substantiating this impact, we can help establish cost-effective sets of computer-based dissection activities that do not require extensive workspace and storage spaces and can be easily scaled to any size classroom.
Hydrodynamic Damping of Microcantilevers Oscillating Near Solid Walls at Low Knudsen Numbers
Authors: Tung Ryan C. , Jana Anirban , Raman Arvind , Sumali Hartono
Published: July 2009

The vibrations of microcantilevers in Atomic Force Microscopes (AFM) or Radio Frequency (RF) switches strongly couple to the viscous hydrodynamics of the surrounding fluid in the vicinity of a solid wall. While prior efforts have focused on squeeze film damping effects at high Knudsen and squeeze numbers, the regime of low Knudsen and squeeze numbers is also very important for which squeeze film models need to be discarded in favor of unsteady Stokes hydrodynamics. We present convenient semi-analytical expressions for the unsteady viscous hydrodynamic functions of slender microbeams oscillating near solid walls in terms of key non-dimensional numbers. Using these expressions it becomes possible to predict semi-analytically the quality factors of multiple modes of microcantilever beams near solid walls in diverse applications ranging from AFM in liquids to RF microswitches under ambient conditions. The predictions compare favorably with fully three dimensional, transient flow-structure interaction computations as well as with preliminary experiments on cantilevers under ambient conditions.
A Comparison of Virtual Condition Cylinder Evaluation Methods in Coordinate Metrology
Authors: Turek Steven , Anand Sam
Published: July 2009

When a cylindrical datum feature is specified at maximum material condition (MMC) or least material condition (LMC) a unique circumstance arises: a virtual condition (VC) cylindrical boundary must be defined [1]. The geometric relationship between a cylindrical point cloud obtained from inspection equipment and a VC cylinder has not been specifically addressed in previous research. In this research, novel approaches to this geometric analysis are presented, analyzed, and validated. Two of the proposed methods are new interpretations of established methods applied to this unique geometric circumstance: least squares and the maximum inscribing cylinder (MIC) or minimum circumscribing cylinder (MCC). The third method, the Hull Normal method, is a novel approach specifically developed to address the VC cylinder problem. Each of the proposed methods utilizes a different amount of sampled data, leading to various levels of sensitivity to sample size and error. The three methods were applied to different cylindrical forms, utilizing various sampling techniques and sample sizes. Trends across sample size were analyzed to assess the variation in axial orientation when compared to the true geometric form, and a relevant case study explores the applicability of these methods in real world applications.
The Active Guidance Module of a Rail-Bound Vehicle as an Application of Dependability Oriented Design in Self-Optimizing Systems
Authors: Sondermann-Wo¨lke Christoph , Mu¨ller Thomas , Geisler Jens , Tra¨chtler Ansgar , Bo¨cker Joachim
Published: July 2009

Integrating dependability in self-optimizing systems is a challenging task. Self-optimizing systems incorporate on the one hand the opportunity to apply novel solutions to complex mechatronic systems, but on the other hand constitute a possible risk because of non-determined behavior. The dependability concept in this paper covers both aspects: Increasing safety with self-optimization and minimizing the risk of self-optimization. This dependability concept is combined with the self-optimization process of the active guidance module which is currently under development at the Collaborative Research Center 614 at the University of Paderborn.
Sharing Information Throughout a Product Lifecycle via Markup of Product Models
Authors: Ding Lian , Davies Dannie , McMahon Chris
Published: July 2009

The advances in wireless communication and the Internet are leading to an ever-more-global economy and unprecedented changes in business processes. Such a highly competitive global market demands that engineering companies must consider the entire product lifecycle and take advantages of different regions of the world by collaboration between groups based in different geographic locations. The experiences of collaborative enterprises have shown up many issues of communication and information sharing between separate teams or different users at different stages of a product lifecycle. This paper proposes a new strategy to strengthen information sharing among users and partners through the whole product lifecycle. The proposed method utilizes a CAD model to act as a centre-carrier to link the information generated by different users, especially at later stages of the product lifecycle, no matter which formats of the product (i.e., the original CAD model or its derived lightweight representations) the users own. The method provides further support in sharing and retrieving relevant information directly via the CAD model.
An Inverse Method to Determine Boundary Temperature and Heat Flux for a 2D Steady State Heat Conduction Problem
Authors: Yu Guangxu , Wen Pihua , Wang Huasheng , Rose John W.
Published: July 2009

Inverse determination of temperature and heat flux on an inaccessible surface of a solid has been widely employed in engineering and research. In this paper a new inverse method was used to predict local boundary temperature and heat flux distributions for a 2D steady heat conduction problem based on temperature measurements at interior wall sample points. The method is a non-iterative meshless boundary allocation method (BAM) using the principle of superposition for linear problems. A case study showed that the BAM method predicts the boundary temperature and heat flux with about the same accuracy as Beck’s function specified method but uses less computing time. Error analysis of thermocouple position and measurement was also carried out. More difficult problems such as those with multiple materials and non-rectangular geometries can also be treated by BAM.
Design and Fabrication of a Microfluidic Pressure Inverter
Authors: Palican Andrew K. , Chavez Silvio A. , Mountain Jeffrey R.
Published: July 2009

Fluidic inverters, or venturi effect vacuum pumps, are commonly used in industrial components that provide a point of use vacuum from an existing compressed air infrastructure. Typical applications include grippers for handling thin sheet, fragile, or polished surface materials. Compressed air usage, representing energy consumption, is significant for these devices. Consequently, a potential customer base has been identified with a need for enhanced energy efficiency. Microfluidic devices represent an approach to address this need. This paper describes the design, fabrication and test process used develop a more energy efficient pressure inverter at the microfluidic scale.
Assessing Commonality and Differentiation for Packaging Family Planning With Application to Medication Labels
Authors: Shooter Steven B. , Cohen Shane , Williams Callida
Published: July 2009

Development of product families involves an interplay of common and differentiating features to address market segments. Considerable research has been conducted by the engineering community to support the development of product families from a product characteristic viewpoint. However, differences in consumable products are not often easily identified so they rely more heavily on the packaging to differentiate to market segments. Metrics, indices and representations have been formulated to support considerations of commonality and differentiation of engineered products. This paper describes the potential for similar approaches to benefit the features of packaging, particularly medication packaging. The potential benefit of such approaches reach beyond marketing and sales. There is a considerable opportunity for improving dispensing of medications because packaging confusion has been recognized as a serious problem, where misidentification can be lethal. With tens of thousands of drug varieties and growing, a packaging metric is necessary. This paper presents a proposed metric along with three supporting case studies.
Thermoelastic Damping in Axially Stressed Beam
Authors: Kumar Sandeep , Haque Amanul
Published: July 2009

Zener’s approximate expression for thermoelastic damping was first known attempt to quantify the thermoelastic damping. Recently, an exact expression of thermoelastic damping for thin unstressed beams, which is widely used, is arrived at. Further, it has been experimentally verified that application of tensile axial stress results in increase in the Q-factor. Since the existing expressions do not take into account the effect of axial stress thermoelastic-damping expression is revised in order to accommodate the effect of axial stress on Q-factor. This expression explains the general behavior observed in experiments. In limiting case of unstressed beam, this new expression converges to current expression for thermoelastic damping.
Towards Scaled Designing and Testing of Unmanned Aerial Vehicle Missions
Authors: Sevcik Keith W. , Oh Paul Y.
Published: July 2009

Today’s UAVs are being tasked to fly missions in increasingly difficult environments. Buildings, trees and thin wires form challenging terrain for the UAV to negotiate. The current paradigm of UAV research typically moves from computer simulation and individual subsystem testing to full integration in the field. The reactions of control algorithms to realistic sensor data are difficult to capture in simulation and can result in costly crashes. This paper introduces a methodic approach to developing UAV missions. A scaled down urban environment provides a facility to perform testing and evaluation (T&E) on control algorithms before flight. A UAV platform and test site allow the tuned control algorithms to be verified and validated (V&V) in real world flights. The resulting design methodology reduces risk in the development of UAV missions.
Consistency Constraint Allocation in Augmented Lagrangian Coordination
Authors: Allison James T. , Papalambros Panos Y.
Published: July 2009

Many engineering systems are too complex to design as a single entity. Decomposition-based design optimization methods partition a system design problem into subproblems, and co-ordinate subproblem solutions toward an optimal system design. Recent work has addressed formal methods for determining an ideal system partition and coordination strategy, but coordination decisions have been limited to subproblem sequencing. An additional element in a coordination strategy is the linking structure of the partitioned problem, i.e., the allocation of constraints that guarantee that the linking variables among subproblems are consistent. There can be many alternative linking structures for a decomposition-based strategy which can be selected for a given partition, and this selection should be part of an optimal simultaneous partitioning and coordination scheme. This paper develops a linking structure theory for a particular class of decomposition-based optimization algorithms, Augmented Lagrangian Coordination (ALC). A new formulation and coordination technique for parallel ALC implementations is introduced along with a specific linking structure theory, yielding a partitioning and coordination selection method for ALC that includes consistency constraint allocation. This method is demonstrated using an electric water pump design problem.
Design of a Smart Wheel
Authors: Gobbi M. , Mastinu G. , Rocca G.
Published: July 2009

A new smart wheel has been designed and modelled. The smart wheel is able to measure the three forces and the three moments acting at the wheel-ground interface. The wheel is based on an original structural concept and appears to be rather simple to be implemented in future automobiles. The paper presents the concept, the design issues and the performances of such a device. The structural part is composed basically by three spokes whose deformations (depending on the forces applied to the wheel) are sensed by means of strain gauges. The strain gauges signals can be filtered, amplified and digitally converted before they are stored or transmitted to a remote receiver. Multi-Objective Programming has been used to design the system. The optimal values of the smart wheel parameters (stiffness of the three spoke structure, geometry of each spoke and joint shape, strain gauges positions.) have been calculated. A particular joint structure, which do realize the physical link between the three spoke structure (wheel hub) and the wheel rim, is designed by using topology optimization techniques in order to improve the smart wheel performance. The performance of the smart wheel fits well the need of improving the active safety of automobiles. In other terms, the information given by the wheel, allowing to sense the three forces and the three moments, should lead to considerable improvement of the ABS and ESP/VDC performance with respect to today control logics.
A General Architecture for Distributed VR Interfaces
Authors: Batkiewicz Thomas , Seth Abhishek , Walter Bryan , Knutzon Jared , Oliver James H.
Published: July 2009

This paper describes a software architecture useful in creating new virtual reality interfaces across a clustered network of computers. The architecture takes advantage of a concept common to desktop application development, the event loop, and provides a method by which it can be shared effectively between nodes in a cluster. This method improves upon the common replication approach to cluster synchronization by creating a single, simple object to share, as well as by supporting node specialization in a generic cluster. The method is designed to be easily added to existing applications as well as speed the development of virtual reality interface prototypes. An example application is discussed to demonstrate the current capabilities and limitations of the architecture. Future implications and improvements are also discussed.
One Degree of Freedom Gyroscopic Mechanism for Wave Energy Converters
Authors: Bracco Giovanni , Giorcelli Ermanno , Mattiazzo Giuliana
Published: July 2009

Sea waves are one of the most interesting and well distributed renewable energy sources in the world. At the current state of the art, all the existing sea wave energy conversion systems are designed to operate offshore, mainly in the oceans where the waves’ height is definitely high. In the Mediterranean Sea, waves are generally low, except under particular meteorological conditions. Thus, it is necessary to develop devices that can exploit other properties of the waves instead of their height, like wave slopes. In this work a solution for this application is analysed, based on a conversion device characterised by floating positioning (without fixed link or basement at depth level), vertical axis geometry (to exploit any kind of wave, regardless of their direction, without the need for orientation systems), working principle based on an inertial system obtained by a rotor thanks to gyroscopic effect (that can be tuned to maximise the efficiency of the transformation process), and ability to work even with low amplitude waves (up to 0.5 m) typical of the Mediterranean Sea. The work follows three steps: first of all, the mechanical system is described with an analytical approach, secondly the mathematical model is implemented, and, finally, it’s tested in simulated sea environments. A system analytical model will be shown and some numerical results will be remarked.
Technology Infusion: An Assessment Framework and Case Study
Authors: Suh Eun Suk , Furst Michael R. , Mihalyov Kenneth J. , de Weck Olivier L.
Published: July 2009

Many product manufacturing companies in today’s environment constantly need to develop new technologies and infuse them into their line of products to stay ahead of the competition. Most new technologies only deliver value once they are successfully infused into a parent system. However, there has been very little research done to develop formal methodologies to assess the impact and implication of new technology infusion into existing products. In this paper, a systematic process framework to quantify and assess the impact of technology infusion early in the product planning cycle is proposed. The proposed methodology quantitatively estimates the impact of technology infusion through the use of a Design Structure Matrix (DSM) and the creation of a Delta DSM (ΔDSM) describing the changes to the original system based on the infused technology. The cost for technology infusion is then estimated from the ΔDSM, and the market impact of the technology is calculated using customer value (utility) curves for customer relevant system performance measures. Finally, the probabilistic ΔNPV of a newly infused technology is obtained using Monte Carlo simulation. The proposed methodology was demonstrated on a complex printing system, represented as an 84 element DSM with a density of 3.7%, where a newly developed value enhancing technology was infused into the existing product. The result shows that a positive marginal net present value ΔNPV can be expected, despite the new technology causing an invasiveness of 8.5% to the existing design. The methodology can be applied in a rigorous and repeatable manner, opening up possibilities for further implementation of the proposed framework, including analysis of the interactions amongst technologies.
Viscoelastic Damping of Ortho-Planar Springs
Authors: Anderson Sterling , Jensen Brian D.
Published: July 2009

This paper presents the design of a damped ortho-planar spring that uses viscoelastic constrained-layer damping to reduce the free response oscillations of the spring and suppress modal resonances in that response. Background, theory, and applications surrounding fully-compliant ortho-planar springs and viscoelastic damping treatments are first discussed. Next, the effect of various constrained layer thickness on the spring constant, damping ratio, equivalent viscous damping ratio, modal frequencies, and modal damping ratios are compared, and trends discussed. The results show that the equivalent viscous damping co-efficient of the viscoelastically-damped spring can be increased to nearly 2.5 times that of the reference configuration without significantly changing the size of the constraining layer or the spring constant of the ortho-planar spring. Viscoelastically-damped ortho-planar springs are also shown to successfully remove mechanical noise from a contact resistance test stand.
Integrating Concept Selection in a Software Development Process
Authors: Singiresu Manoj , Boggavarapu Kumar , Takai Shun
Published: July 2009

Although a similarity between software and product development processes exists, concept selection is not treated as a core stage in software development whereas it is an important stage in product development. In this paper, we propose to apply concept selection methodologies in design engineering (modularized Quality Function Deployment (QFD) and perceptual concept evaluation methodologies) to software development. In particular, we demonstrate how these methods may be used for software architecture and software module concept selections. Modularized QFD matrices help software developers relate customer requirements to software requirements, and then to software module requirements. At the same time, importance of customer requirements is allocated to software requirements and then to software module requirements. These requirements and normalized worth serve as concept evaluation criteria and their weights. The proposed approach is illustrated using image search software as an example.
Kinematic Design and Bond Graph Modeling of an Inertia-Type Infinitely Variable Transmission
Authors: Berselli Giovanni , Stecki Jacek S.
Published: July 2009

A fully mechanical infinitely variable transmission (IVT) based on the use of an oscillating inertia is described. The system includes a four-bar linkage mechanism, an epicyclic gear train and a pair of one-way clutches. The proposed IVT can be used in place of both gear-box and clutch in self-propelled vehicles. A basic model is used for a first attempt sizing of the transmission kinematic parameters. A more accurate model, achieved using Bond Graphs, is used to investigate the dynamic effect of inertias, one-way clutch compliance, and minor design changes in the kinematic parameters. Finally, simulations compare the behavior of a car fitted with a manual gear-box and the same car fitted with the proposed IVT.
Rationale and Methodology for Deploying Axiomatic Design in Interdisciplinary Capstone Design Courses
Authors: Gallup Lloyd , McCormack Jay , Beyerlein Steven , Odom Edwin
Published: July 2009

Capstone design courses require balanced attention to structured design processes as well as development of high quality design solutions. Process elements are commonly built into these courses through intermediate deliverables such as progress reports, design reviews, design reports, and forums for displaying prototypes as well as hardware. Despite this formal structure, steady evolution of design quality is not assured. Personal interaction with instructors, mentors, and clients is needed to evaluate intermediate designs and focus team efforts on design deficiencies as well as on promising design features. Clarification of functional requirements, determination of optimal design parameters, and implementation of viable solutions often requires considerable instructor and design team iteration. Design intent behind instructor feedback given at these junctures is not immediately obvious to many students. This paper outlines the rationale behind selecting and the methodology for deploying axiomatic design as a primary tool in an interdisciplinary design course. The selection of axiomatic design was based on 1) limited bandwidth for the introduction of new tools, 2) the desire to facilitate communication about design attributes between students and instructors, and 3) to provide continuity of application between various phases of the design process.
Five Position Synthesis of Spherical (6, 7) Linkages
Authors: Soh Gim Song , McCarthy J. Michael
Published: July 2009

This paper presents a geometric synthesis procedure for spherical (6, 7) linkages, often known as spherical six-bar linkages, based on adding two spherical RR constraints to a spherical 3R serial chain. The design can use the spherical 3R chain to shape the movement of the linkage and identify a set of task positions that shape the trajectory of the end-effector. We use five task positions to completely specify the two RR chains that constrain the system to one degree-of-freedom. This procedure yields spherical versions of the various topologies for the planar Watt and Stephenson six-bar linkages. We find that for any design problem we obtain at a minimum of two design candidates for the Watt-type linkage, and as many as 185 different design for all of the topologies obtained by constraining the spherical 3R chain. Wampler’s method for the analysis of spherical loops is used to analyze these linkages. An example design is presented in detail.
An Industrial Case Study of Design Methodology and Decision Making for Automotive Electronics
Authors: Gustavsson Ha˚kan , Sterner Jan
Published: July 2009

The growth rate of R&D activities in automotive industry brings an increased need for transfer of design knowledge. This, in combination with growing complexity of the product puts new demands on the decision process. In this paper, decision methods used within the R&D department of an international vehicle manufacturer has been investigated through interviews and surveys. The main focus has been to identify and analyze methods used by the individual roles within different development teams. The survey reveals that a majority of the respondents use unstructured methods for resolving decision issues. When respondents were asked about their preferences there was an expressed need for more structured methods. Among these, two methods are elaborated that are well established within the product development process: expert support and guidelines, but also on methods training in general. A third conclusion is to redirect the current decision process to build on more structured methods through training. This work has contributed also by identifying the company best practice. The long term goal is to have all development teams adopt one common development process at the team level.
Kinematic Analysis of a Compliant Microplatform
Authors: Correa Julio , Crane Carl , Xie Huikai
Published: July 2009

Mechanisms formed by rigid elements are not suitable for applications at the microlevel due to manufacturing limitations. For the same reason, devices for microelectromechanical systems (MEMS) are basically planar mechanisms. This paper addresses a microplatform able to move in the three dimensional space. It is formed by bimorph actuators connected to the central platform by compliant elements. The forward and reverse analyses for the microplatform are presented.