bluuebunny/crossref_metadata_2025 huggingface dataset:
Degradation Analysis Using Inverse Gaussian Process Model With Random Effects: A Bayesian Perspective
Authors: Peng Weiwen , Huang Hong-Zhong , Wang Zhonglai , Yang Yuanjian , Liu Yu
Published: February 2014

The inverse Gaussian (IG) process is recently proposed as a flexible family of models for degradation modeling. This paper investigates Bayesian analysis of IG process model with random effects for degradation modeling. Novel features of Bayesian analysis are the natural manners for incorporating subjective information and pooling of random effects information between test specimens. An IG process model with random effects named as the random drift IG process model is investigated using the Bayesian method. In addition, a Bayesian χ2 goodness-of-fit test is developed for this Bayesian analysis. The applicability of the Bayesian method for degradation analysis with this IG process model is demonstrated with a classic example.
Tribo-Dynamics of Differential Hypoid Gears
Authors: Mohammadpour Mahdi , Theodossiades Stephanos , Rahnejat Homer
Published: February 2014

Differential hypoid gears play an important role on the Noise, Vibration and Harshness (NVH) signature of vehicles. Additionally, friction developed between their teeth flanks under extreme loading conditions adds another source of power loss in the drivetrain which can mitigate vibrational energy. The paper considers the coupling between dynamics and analytical tribology to study dynamic response of hypoid gear pairs with lateral motion of support shafts also included in the analysis framework. Friction of teeth flank pairs is assumed to follow elastohydrodynamic lubrication under elliptical point contact geometry with lubricant film behavior conforming to Non-Newtonian thermal shear, also with surface asperity interactions. Tooth Contact Analysis (TCA) has been used to obtain the input data required for the investigation. The dynamic behavior and efficiency of a differential hypoid gear pair under realistic operating conditions is determined. The proposed tribo-dynamic framework provides a useful platform to conduct an extensive series of parametric studies.
Traversability Analysis of a Novel One-DOF Robotic Leg
Authors: Birglen Lionel , Ruella Carlos
Published: February 2014

In legged mobile robotics the most common approach is to design fully actuated legs with several degrees of freedom (DOF) in order to successfully navigate through rough terrains. However, simpler leg architectures with as few as one-DOF have been developed in the past to achieve the very same goal. The ability of these simpler legs to traverse uneven terrains is arguably limited with respect to multi-DOF designs, but in some applications the reduction of the DOF and hence, of the number of actuators, as well as the simplicity of the associated control could be a great advantage and the decisive argument. In this paper, the authors propose a novel one-DOF robotic leg that has been specially designed to achieve the greatest robustness possible with respect to the difficult terrains it has to traverse. In order to do that, a method to analyze and optimize any one-DOF robotic leg with respect to its ability to overcome obstacles is proposed here. This method is based on a simple and efficient novel technique to generate synthetic terrains combined with a simulation algorithm estimating the traversability of the particular one-DOF leg design under scrutiny. To illustrate the generality of the proposed method, it is used to design both an optimal leg with the architecture presented here for the first time and also, one with the most common one-DOF leg architecture found in the literature.
Experimental Identification of the Complex Dynamics of a Strongly Nonlinear Spacecraft Structure
Authors: Noël J. P. , Renson L. , Kerschen G.
Published: February 2014

The present paper addresses the identification of a real-life spacecraft structure possessing an impact-type nonlinear component. The complete identification procedure, i.e. from nonlinearity detection to parameter estimation, is carried out using experimental data collected during a typical spacecraft qualification test campaign. The complementary use of several techniques reveals particularly interesting and complex phenomena such as nonlinear jumps, nonlinear modal interactions, internal force relaxation and chattering during impacts.
Experimental Assessment of the Ride Comfort of Farm Tractors
Authors: Dominoni Stefano , Gobbi Massimiliano , Mastinu Giampiero , Previati Giorgio
Published: February 2014

The paper is focused on the assessment of the ride comfort of that farm tractors. The problem of assessing the ride comfort is crucial due to the fact that operators spend part of their own lives on board of such machines, exposed to whole body vibrations potentially harmful for their health.

The paper deals with the experimental measurement of the relevant vibration occurring at the tractor body, at the cabin and at the seat. The focus is on which accelerations are actually relevant and have to be taken into account.

A number of farm tractors have been instrumented and run under monitored conditions. The test track was equipped with a number of cleats able to force at resonance the cabin and the seat. The six motions of the tractor body and the six motions of the cabin were measured. The motion of the seat was measured. The signals have been processed in the time domain.

Some interesting occurrence have been highlighted referring to the amplification that a badly regulated seat can provide under certain circumstances.

The comfort index was computed according with ISO 2631 and other standards. The acceleration of the seated subject was described at different positions on the body. It turned out that the acceleration of the head was particularly relevant for establishing a comparison among different tractors.

Synthetic indices have been derived from the measured data able to correlate the subjective drivers’ feeling with the measured level of vibration.

The conclusion is that for a proper comparison of the ride performance of different farm tractors a huge number of measurements are needed. There is no possibility to record only the vertical accelerations to assess the ride comfort of farm tractors.
A Methodology for the Appropriation and the Isolation of Nodal Diameter Modes in Cyclic Symmetric Structures
Authors: Nyssen Florence , Viguié Régis , Simon Daniel , Golinval Jean-Claude
Published: February 2014

This paper presents a methodology enabling the appropriation and the isolation of a chosen nodal diameter modes in cyclic symmetric structures. In particular, a study about the minimum number and the optimized location of the excitation sources required in laboratory conditions to isolate a specific nodal diameter mode is conducted. This work includes a theoretical approach based on energy concepts. It is followed by the numerical and experimental validations on a stator stage of an axial compressor. The concept of modal appropriation is investigated here as the first step of the calibration procedure before engine tests.
Automatic 3D Documentation Method for Manufacturing Processes
Authors: Strang Daniel , Schüle Anselm , Anderl Reiner
Published: February 2014

Product documentation plays an important role in product creation. Many parts of the documentation are used for manufacturing, assembly and quality assurance processes. Until today the leading document for manufacturing processes is the engineering drawing. With more complex product designs the clarity of the drawings decreases. Modern technologies enable the transition to a paperless manufacturing documentation without the need for expensive licenses. 3D-PDF technology offers a way to provide manufacturers with 3D-CAD models containing the appropriate product manufacturing information.

In this paper a generative document that provides only the essential information for certain manufacturing steps is presented. 3D-PDF technology is used to present the results to the machinist. The recommended documentation provides two different views: the input and output status of a product at a specific manufacturing station. Those views are created automatically from the ERP database containing manufacturing knowledge of the product. The presented models are supplemented with general information, e.g. material, designer, general tolerances. The limitation on necessary information for only one manufacturing step at a time increases the comprehensibility of the product documentation and thus accelerates the manufacturing process and improves product quality.
Reliability Analysis of Automotive Semi-Axle on Basic of Imprecise Probability
Authors: Liu Zheng , Huang Hong-Zhong , He Liping , Wang Zhonglai , Xiao Ning-cong
Published: February 2014

Most reliability models in the classical reliability theory use probability theory to quantify information under uncertainty and these models have a high demand of available data. While in practical applications, data related to system sand components are usually sparse or incomplete, moreover, some quantification of uncertainty should be based on subjective information and moreover subjective information may often be expressed in natural language. In these cases, classical reliability theory can not provide an effective way for the reliability analysis of systems. As a generalization of probability theory, imprecise probability theory may provide a tool which is called the natural extension to solve such problems. Research on the application of imprecise probability in reliability engineering has made a great progress. Unfortunately, this is all about theory and there are few applications and cases in practice. Therefore, this paper tried to overcome the flaws and shortcomings of classical reliability theory, and apply some theories of imprecise probability in practical engineering, and conduct reliability analysis on automotive semi-axle with establishing imprecise probability-based reliability model of automotive semi-axle. Natural extension is undoubtedly a powerful tool to compute reliability measures, however, when number of variables is large; the computation of natural extension is very difficult. Effective methods to simplify and build reliability models deserve more debate in the future.
Using Time-Periodicity for Inducing Energy Transfer Between Vibration Modes
Authors: Dohnal Fadi , Tondl Aleš
Published: February 2014

Introducing time-periodicity in system parameters may lead, in general, to a dangerous and well-known parametric resonance. In contrast to such a resonance, a properly tuned time-periodicity is capable of transferring energy between vibration modes. Time-periodicity in combination with system damping is capable of efficiently extracting vibrational energy from the system and of amplifying the existing damping affecting transient vibrations. Operating the system at such a specific time-periodicity, the system is tuned at a parametric anti-resonance. The basic principle of this concept has been studied theoretically and was proven experimentally. The physical interpretation of this concept was proposed in “Damping by Parametric Stiffness Excitation: Resonance and Anti-Resonance”, Journal of Vibration and Control, 2008, for a multiple degrees of freedom system. The present contribution highlights those findings on a multiple degrees of freedom system. It is illustrated that a parametric anti-resonance is connected to inducing an energy transfer between two of the many vibration modes of the underlying system with constant coefficients. The induced energy transfer can be utilized to transfer the vibration energy from low frequency to high frequency or vice versa or, in case of system damping, to a more efficient dissipation of vibrational energy. The achievable energy dissipation is most significant if an energy transfer is induced between a lightly damped mode and a strongly damped mode.
A Reliability Allocation Method Considering Failure Dependence
Authors: Chen Zhong-Zhe , Liu Yu , Huang Hong-Zhong , Wu Xuehai , He Liping
Published: February 2014

Traditional reliability allocation methods are based on the assumption that the subsystems of a system are independence in order to simplify the problem. However, this assumption could deviate from the engineering practice. To achieve the reliability requirement of the system, the subsystems must be allocated high reliability based on traditional reliability allocation approaches which neglect the dependence between subsystems. To solve this problem, an improved reliability allocation method is developed in this paper. Firstly, the failure dependence between subsystems of mechanical systems is characterized using Copula functions. Secondly, a reliability prediction model considering failure dependence is formulated based on Copula function, Furthermore, the improved reliability allocation method according to relative failure rate is proposed. Finally a numerical case is presented to illustrate the proposed approach. The optimal allocation result shows that the system can achieve reliability requirement without high reliability demand to some subsystems, which could reduce the unnecessary cost.
Fractional Model for Malaria Disease
Authors: Pinto Carla M. A. , Tenreiro Machado J. A.
Published: February 2014

In this paper we study a fractional order model for malaria transmission. It is considered the integer order model proposed by Chitnis et al [1] and we generalize it up to become a fractional model. The new model is simulated for distinct values of the fractional order. Are considered two initial conditions and a set of parameter values satisfying a value of the reproduction number, R0, less than one, for the integer model. In this case, there is co-existence of a stable disease free equilibrium and an endemic equilibrium. The results are in agreement with the integer order model and reveal that we can extend the dynamical evolution up to new types of transients. Future work will focus on analytically prove some of the results obtained.
Vibration Energy Harvesting Using Multi-Stable Two Degree-of-Freedom Nonlinear Dynamics
Authors: Wu Z. , Harne R. L. , Wang K. W.
Published: February 2014

In this research, we studied the integrated dynamics of a coupled linear oscillator-bistable energy harvester system. The method of harmonic balance together with perturbation analysis are used to predict the existence and stability of the bistable device interwell vibration. The influences of important parameters on tailoring the coupled system response are investigated to determine principles for improved energy harvesting performance. We demonstrate analytically that for excitation frequencies in a bandwidth less than the natural frequency of the linear oscillator, the additional linear system may substantially intensify the bistable harvester power generation as compared to a single bistable device. Moreover, the linear-bistable coupled system may introduce a stable out-of-phase dynamic between the linear and bistable elements around the resonance of the linear oscillator, enhancing the performance of the harvester by providing for a second interwell response. Key analytical findings are confirmed through experiments, validating the predicted trends and demonstrating the advantages of the coupled system for energy harvesting.
A New Approach for Designing a Gearbox for a New Kind of Independently Controllable Transmissions
Authors: Wünsch Andreas , Tsay Der-Min , Vajna Sándor , Schabacker Michael
Published: February 2014

This paper deals with a new approach for the development of a gearbox of a new kind of variable transmissions, the independently controllable transmission (ICT). It provides a continuous output speed which is independent of the input speed. In the beginning the requirements of a gearbox are mentioned. Design guidelines are the starting point for the design process of the ICT gearbox. Some of these guidelines will be applied on the gearbox of the ICT to model rules which were needed for the design process. The process of the product design of the gearbox can be improved more efficiently by using multidisciplinary design optimization with evolutionary algorithms and topology optimization. This paper describes an approach for the development of this gearbox and the preparation of the optimization models based on a process chain, which is a guide for the next steps of creating the design process in detail. The first step is a parametric CAD model which consists of different parts and provides the complete design space of the gearbox.
Trigger Features on Prototypes Increase Preference for Sustainability
Authors: She Jinjuan , MacDonald Erin F.
Published: February 2014

The gap between customers preferring sustainable products in surveys and actually buying sustainable products in the market can be addressed through design. Our previous research proposed a method for creating design features that trigger thoughts of sustainability, termed ST (sustainability triggering) features. In the research presented here, a selection of ST features generated from the previous experiment was designed into realistic toaster prototypes. Subjects participated in a test vs. control purchase experiment, in which some “customers” saw a subset of toasters with ST features during purchasing tasks and some did not. First, subjects selected a subset of toasters for purchase. Then, they chose one from that set for a final purchase. Next, they wrote an email with instructions on how to select a toaster to a hypothetical purchasing agent. Finally, they answered interview questions and rated/ranked toasters. The coded email and interview results demonstrate that exposure to ST features significantly triggered the possible use of sustainability as a purchase criterion.
A Methodology and a Software Platform to Implement an Eco-Design Strategy in a Manufacturing Company
Authors: Germani Michele , Mandolini Marco , Marconi Marco , Dufrene Maud , Zwolinski Peggy
Published: February 2014

During past years several eco-design methodologies have been previously defined but none can be easily integrated in the traditional design process of manufacturing companies. This paper wants to overcome this lack and aims to define a methodology, called G.EN.ESI, to help also those designers without a specific know-how on eco-design, during the development of sustainable products. The methodology has been also contextualized in the traditional product design process, re-engineering this one with new input/output data, actors and specific tools, to demonstrate the applicability in real contexts.

The re-engineered process is supported by a new set of integrated software tools, called G.EN.ESI platform. It is made of four tools for the definition of the product life cycle model, two tools for the evaluation of the environmental impact and Life Cycle Cost and a tool to guide the decision-making process during the re-design phase of a product. Furthermore, a web module to retrieve the necessary data from the supply chain subjects has been defined. Finally, the link with the CAD and PLM systems is proposed to increase the usability.
A Task Driven Approach to Unified Synthesis of Planar Four-Bar Linkages Using Algebraic Fitting of a Pencil of G-Manifolds
Authors: Ge Q. J. , Zhao Ping , Purwar Anurag
Published: February 2014

This paper studies the problem of planar four-bar motion approximation from the viewpoint of extraction of geometric constraints from a given set of planar displacements. Using the Image Space of planar displacements, we obtain a class of quadrics, called Generalized- or G-manifolds, with eight linear and homogeneous coefficients as a unified representation for constraint manifolds of all four types of planar dyads, RR, PR, and PR, and PP. Given a set of image points that represent planar displacements, the problem of synthesizing a planar four-bar linkage is reduced to finding a pencil of G-manifolds that best fit the image points in the least squares sense. This least squares problem is solved using Singular Value Decomposition. The linear coefficients associated with the smallest singular values are used to define a pencil of quadrics. Additional constraints on the linear coefficients are then imposed to obtain a planar four-bar linkage that best guides the coupler through the given displacements. The result is an efficient and linear algorithm that naturally extracts the geometric constraints of a motion and leads directly to the type and dimensions of a mechanism for motion generation.
Design Analytics in Consumer Product Design: A Simulated Study
Authors: Lewis Kemper , Van Horn Dave
Published: February 2014

A growing area of research in the engineering community is the use of data and analytics for transforming information into knowledge to design better systems, products, and processes. Data-driven decisions can be made in the early, middle, and late stages in a design process where customer needs are identified and understood, a final concept for a design is chosen, and usage data from the deployed product is captured, respectively. Design Analytics (DA) is a paradigm for improving the core information-to-knowledge transformations in these stages of a design process resulting in better performing and functioning products that reflect both explicit and implicit customer needs. In this paper, a simulator is used to model usage of a hypothetical refrigerator and generate artificial data driven by four different customer behavior profiles with variation. The population of customers is randomly divided among the four behavior profiles so that the underlying customer preferences are unknown to the experimenter prior to data analysis. The purpose of the simulation is to illustrate the use of DA in the late stage of a design process to improve the transition from an existing product to the next generation product. Metrics are developed to analyze the product usage data, and both prevailing and subtle usage trends are identified. After conclusions are made, the study proceeds to the early and middle stages of a subsequent design process where a hypothetical next-generation refrigerator is conceptualized.
Initiating Development of a Concept Inventory for Engineering Design
Authors: Mountain Jeffrey R.
Published: February 2014

It has been stated that the topic of design is not conducive to assessment by concept inventory. While design problems are more ambiguous than problems in analytical subjects, such as physics, statics, or thermodynamics; the broader design education community of scholars might agree on a set of concepts that are essential to the fundamental understanding of design. Following a review of textbooks, industry interviews, and other literary sources, this paper will propose a set of commonly accepted overarching concepts that might form a nucleus of an engineering design concept inventory. This is intended primarily to initiate a dialog among the design engineering education community about the future development of a design concept inventory and it’s applicability in assessing the design content knowledge of undergraduate engineering students prior to entering the profession as graduate engineers.
Toward Supporting the Implementation of User’s Emotional Perceptions During the Design Process of Branded Products
Authors: Rasoulifar Golnoosh , Eckert Claudia , Prudhomme Guy
Published: February 2014

Visual appearance of design plays a critical role in the initial customer perception as well as the emotional response and evaluation of product properties. For branded products, the design of a product must also have distinctive references to the brand values. The successful implementation of the brand value in terms of the physical product properties and product appearance is therefore crucial. This requires product designers and engineering designers working together to create a shared understanding of the brand and the rationale behind the design choices made to implement them. Although communication mechanisms do exist, researchers observed that product designers and engineering designers still do not understand each other well. As the design process progresses the link to original brand values appears to be gradually lost (e.g. through engineering changes and cost reduction activities). Therefore it is important to make sure that the brand identity, and intended emotional responses are maintained throughout the changes. The aim of this paper is to describe the factors contributing to the complexity of communication between product designers and engineering designers related to the development of branded products. Several alternative approaches for supporting this communication are suggested with the objective of making the brand more accessible and understandable to engineers, who are not trained in brand design and aesthetics, and of integrating an engineering viewpoint in early design idea generation and decision making.
The Deformable Wheel Robot Using Magic-Ball Origami Structure
Authors: Lee Dae-Young , Kim Ji-Suk , Kim Sa-Reum , Koh Je-Sung , Cho Kyu-Jin
Published: February 2014

In this paper, we present a deformable wheel robot using the ball-shaped waterbomb origami pattern, so-called magic-ball pattern. The magic-ball origami pattern is a well-known pattern that changes its shape from a long cylindrical tube to a flat circular tube. By using this special structure, a wheel with mechanical functionalities can be achieved without using many mechanical parts. Moreover, because of the characteristic that the structure constrains its own movement, it is possible to control the whole shape of the wheel using only few actuators. And also, from analysis of the wheel structure in kinematic model, the performance of the wheel and determine the condition for actuators can be predicted. We think that the proposed design for the deformable wheel shows the possibility of using origami structure as a functional structure with its own mechanism.
Use of the Jacobian to Verify Smooth Movement in Watt I and Stephenson I Six-Bar Linkages
Authors: Parrish Brian E. , McCarthy J. Michael
Published: February 2014

In this paper we present an algorithm applicable to the Watt I and Stephenson I six-bar linkage designs which determines if a candidate linkage moves smoothly through a desired range of input angles. Intended for use with a synthesis routine our algorithm uses the Jacobian of the linkage to determine if a linkage moves smoothly by identifying the continuous existence of a desired branch of a single circuit for all input angles within a bounded range. With the constraint that the input angle must be contained within the four-bar loop, the determinant of the Jacobian is factored into components that represent the individual linkage loops. The algorithm starts with a linkage of a known configuration which reaches one of the desired task positions to establish the set of signs for these determinants and this set is tracked for consistency throughout the bounded range of input angles. Linkages with defects that exist in a narrow range of input angles are addressed by numerically identifying the input angles which correspond to the minimal value of the Jacobian determinants. We verify that at these input angles the linkage remains on the same branch of the same circuit. A Watt I and Stephenson I six-bar linkage that passes this test will move smoothly through the desired range of input angles. Examples using Mathematica demonstrate the application of the algorithm on both the Watt I and Stephenson I linkage types.
Proposal for a Design Approach for Mechatronic Systems Based on Optimization Design and Case-Based Reasoning
Authors: Casner Didier , Houssin Rémy , Knittel Dominique , Renaud Jean
Published: February 2014

Multidisciplinary systems, such as mechatronic systems, are particularly complex to design because the designer needs knowledge in many fields. This paper is part of a routine process design to optimize the topology of a multidisciplinary system, which is difficult when dealing with more than one discipline or when solutions must be chosen within a set of components and combined. To solve this problem, an approach for the design and optimization of such systems is proposed. It is based on topology optimization, which combines the parametric optimization, using tools like genetic algorithms or particle swarm optimization, and the Case-Based Reasoning to find the best possible solutions by combining and adapting cases within a database or a set of components. This approach is then applied to the design of a gripping tool which will be mounted as a robot effector. This system belongs to the family of mechatronic systems which integrates mechanical, electrical, control and software engineering.
Methods for Prototyping Strategies in Conceptual Phases of Design: Framework and Experimental Assessment
Authors: Camburn Bradley A. , Dunlap Brock U. , Kuhr Rachel , Viswanathan Vimal K. , Linsey Julie S. , Jensen Dan D. , Crawford Richard H. , Otto Kevin , Wood Kristin L.
Published: February 2014

Prototyping may be simultaneously one of the most important and least formally explored areas of design. Over the last few decades, designers and researchers have developed many methodologies for ideation, product architecture, design selection, and many other aspects of the design process. However, there have been relatively few methodologies published regarding the efficient and effective development of prototypes for new products. This research explores a methodology for enhancing the prototyping process. It is founded on extensive literature review of the best practices of engineering prototype development. These findings have been aggregated and form the foundation of a methodology for formulating prototyping strategies. This methodology has then been experimentally evaluated in a controlled design environment, and its effect on the performance of prototypes has been demonstrated. The method consists of a set of guiding questions with corresponding flowcharts and foundational equations that assist the designer to make choices about how to approach the prototyping process in an efficient and effective manner.
Exploring the Utility of Product Dissection for Early-Phase Idea Generation
Authors: Toh Christine A. , Miller Scarlett R.
Published: February 2014

Product dissection is a tool widely used in industry and academia as a means to understand components of existing products and identify opportunities for design. Dissection activities have the potential to impact design creativity because dissection is performed in the early phases of design, which is arguably the most influential phase of the design process. However, researchers have only just begun to explore the relationship between dissection and creativity, and thus little research to date has identified how variations in dissection activities impact creativity. Therefore, in this paper we respond to this research gap by presenting the results of a controlled experiment developed to understand how the type and number of products dissected and the structure and medium of the dissection task (electronic versus physical) impacts creativity. Our quantitative findings (from ANOVAs) are paired with qualitative analysis (interview results) to provide rationale for our results and insights into their cognitive underpinnings. The results from this study indicate that the structure of the dissection activity, the medium of dissection, and the number of products dissected impacts the variety of the generated concepts while the analogical distance and number of products impacts design novelty. These findings are used to develop recommendations for the alteration of dissection methods for inspiring creative thought in engineering design.
Eight Principles Derived From the Engineering Literature for Effective Design for the Developing World
Authors: Mattson Christopher A. , Wood Amy E.
Published: February 2014

This paper reviews the findings of several engineering researchers and practitioners on the topic of design for the developing world. We arrange these findings into eight guiding principles aimed at helping those who are searching for effective and sustainable approaches for design for the developing world. The findings reviewed come from the mechanical engineering discipline, as well as from other engineering disciplines. For each principle, we provide references to various studies as a means of supporting the principle. We also provide a detailed example of each principle. Finally, based on our own experience and based on the many papers reviewed, we provide a succinct list of suggestions for using each principle. Ultimately, we believe that the stated principles help overcome the challenges of design for the developing world, which are often dominated by designer unfamiliarity with poverty and foreign culture, as well as by the constraint of extreme affordability.
A Knowledge Management Method for Supporting Conceptual Design of Product-Service Systems
Authors: Nemoto Yutaro , Akasaka Fumiya , Shimomura Yoshiki
Published: February 2014

Product-Service Systems (PSSs) are regarded as an attractive business concept for manufacturing companies to enhance the value of their products. For designing an effective PSS, it is important to search for value provision opportunities in the entire product life cycle and offer appropriate services to customers at each opportunity. Because both products and services are included in the design object, PSS designers need to use a broader range of knowledge compared with that required in product design. This study proposes a knowledge management method to support designers in the conceptual design phase of PSS. The effectiveness of the proposed method is demonstrated by application to an example of PSS design.
Process Model for Simulation-Based Mechatronic Design
Authors: Dohr Fabio , Vielhaber Michael
Published: February 2014

Although simulation has become a very important aspect in product development today, a study of current design methodologies by Dohr and Vielhaber has shown that there is currently no methodology fully incorporating simulation within the context of mechatronic product development. The results of this study are used to derive specific needs of a simulation-based design process. Based on these requirements a process model for simulation-based mechatronic design is developed which is based on process steps of established design methodologies. In order to integrate simulation, the process model consists of two activity streams: analysis activities are linked to the specific design activities of mechatronic systems. Based on these two streams guidance is provided on which simulation technique should be used for specific activities and how the results from the simulation have to be handled in order to improve design without macro-iterations. With regard to mechatronic interdisciplinarity as well as data and model management, the use of a system model as a platform for the exchange of information and knowledge is integrated into the process model. Finally an outlook on future work regarding the detailing of the process model as well as on the application of the process model is provided.
Diagnostic Analysis of Metamodels’ Multivariate Dependencies and Their Impacts in Many-Objective Design Optimization
Authors: Woodruff Matthew J. , Simpson Timothy W. , Reed Patrick M.
Published: February 2014

While computers are continually getting faster, physical models of complex systems grow more sophisticated and keep pace. Using metamodels can dramatically reduce the time it takes to evaluate a solution for a complex system; however, while the chief virtue of metamodels is that they approximate more computationally expensive models, this is also their main drawback. Metamodels are approximations, and as such they behave differently than the more sophisticated models they approximate. While the metamodels may be accurate approximations, they may also introduce new interdependencies in the response outputs that may hinder search algorithms during optimization. Understanding the impact of the approximation on the subsequent search thus becomes an important part of the problem as models that were computationally expensive ten to fifteen years ago may now run fast enough for use in optimization. In this paper, we use Sobol′ global sensitivity analysis to compare the search performance of a new auto-adaptive many objective evolutionary algorithm solving a challenging product family design problem with both the original analysis and a second-order response surface approximation of the original analysis. Interdependencies in the response outputs are found to result from the problem formulation used rather than the underlying model in this case. Search operator selection by the auto-adaptive evolutionary algorithm is shown to be consistent with the model sensitivities found by global sensitivity analysis.
Hierarchical Design of Composite Materials With Negative Stiffness Inclusions Using a Bayesian Network Classifier
Authors: Matthews Jordan , Klatt Timothy , Seepersad Carolyn C. , Haberman Michael , Shahan David
Published: February 2014

Recent research in the field of composite materials has shown that it is theoretically possible to produce composite materials with macroscopic mechanical stiffness and loss properties that surpass those of conventional composites. This research explores the possibility of designing and fabricating these composite materials by embedding small volume fractions of negative stiffness inclusions in a continuous host material. Achieving high stiffness and loss from these materials by design, however, is a nontrivial task. This paper presents a hierarchical multiscale material model for these materials, coupled with a set-based, multilevel design approach based on Bayesian network classifiers. Bayesian network classifiers are used to map promising regions of the design space at each hierarchical modeling level, and then the maps are intersected to identify sets of multilevel or multiscale solutions that are likely to provide desirable system performance. Length scales range from the behavior of the structured microscale negative stiffness inclusions to the effective properties of mesoscale composite materials to the performance of an illustrative macroscale component — a vibrating beam coated with the high stiffness, high loss composite material.
Off-Road Vehicle Dynamics Mobility Simulation With a Compaction Based Deformable Terrain Model
Authors: Madsen Justin , Seidl Andrew , Negrut Dan
Published: February 2014

This paper discusses the terramechanics models developed to incorporate a physics-based, three dimensional deformable terrain database model with vehicle dynamics mobility simulation software. The vehicle model is contained in Chrono, a research-grade C++ based Application Programming Interface (API) that enables accurate multibody simulations. The terrain database is also contained in a C++ based API, and includes a general tire-terrain interaction model which is modular to allow for any tire model that supports the Standard Tire Interface (STI) to operate on the terrain. Furthermore, the ability to handle arbitrary, three dimensional traction element geometry allows for tracked vehicles (or vehicle hulls) to also interact with the deformable terrain. The governing equations of the terrain are based on a soil compaction model that includes both the propagation of subsoil stresses due to vehicular loads, and the resulting visco-elastic-plastic stress/strain on the affected soil volume. Non-flat, non-homogenous and non-uniform soil densities, rutting, repeated loading and strain hardening effects are all captured in the vehicle mobility response as a result of the general 3-D tire/terrain model developed. Pedo-transfer functions allow for the calculation of the soil mechanics model parameters from existing soil measurements. This terrain model runs at near real-time speed, due to parallel CPU and GPU implementation. Results that exercise the force models developed with the 3-D tire geometry are presented and discussed for a kinematically driven tire and a full vehicle simulation.
A Privacy Preserving Data Mining Methodology for Dynamically Predicting Emerging Human Threats
Authors: Manohar Gautam , Tucker Conrad
Published: February 2014

This paper proposes a privacy preserving data mining driven methodology for predicting emerging human threats in a public space by capturing large scale, real time body movement data (spatial data represented in X, Y, Z coordinate space) using Red-Green-Blue (RGB) image, infrared depth and skeletal image sensing technology. Unlike traditional passive surveillance systems (e.g., CCTV video surveillance systems), multimodal surveillance technologies have the ability to capture multiple data streams in a real time dynamic manner. However, mathematical models based on machine learning principles are needed to convert the large-scale data into knowledge to serve as a decision support system for autonomously predicting emerging threats, rather than just recording and observing them as they occur.

To this end, the authors of this work present a privacy preserving data mining driven methodology that captures emergent behavior of individuals in a public space and classifies them as a threat or not a threat, based on the underlying body movements through space and time. An audience in a public environment is presented as the case study for this paper with the aim of classifying individuals in the audience as threats (or not), based on their temporal body behavior profiles.
The Assessment of Product Archaeology as a Platform for Contextualizing Engineering Design
Authors: Lewis Kemper , Moore-Russo Deborah , Cormier Phil , Olewnik Andrew , Kremer Gül , Tucker Conrad , Simpson Tim , Ashour Omar
Published: February 2014

Many engineering departments struggle to meet “the broad education necessary to understand the impact of engineering solutions in a global, economic, environmental, and societal context” (Outcome h) that is required for ABET. As a result, engineering students receive meaningful contextual experiences in piecemeal fashion and graduate with a lack of concrete competencies that bridge knowledge and practice in the global world in which they will live and work. By considering products as designed artifacts with a history rooted in their development, our product archaeology framework combines concepts from archaeology with advances in cyber-enhanced product dissection to implement pedagogical innovations that address the significant educational gap. In this paper, we focus on assessing elements of a sustainable and scalable foundation that can support novel approaches aimed at educating engineering students to understand the global, economic, environmental, and societal context and impact of engineering solutions. This foundation is being developed across a network of partner institutions. We present recent results from freshman, sophomore, and senior courses at two of the partners in the national network of institutions.
Experimental and Numerical Validation on a Continuous Modulated Wave-Form Command Shaping Control Considering the Effect of Hoisting
Authors: Alhazza Khaled A.
Published: February 2014

A large body of research has been dedicated to input-shaping control techniques. Most of the research assumes constant cable length, due to the complexity of the dynamics associated with changing cable length (hoisting). Current techniques tend to split maneuvers into three consecutive stages, raising the payload from an initial point, then moving it horizontally using input-shaping, and finally lowering it to a final location. These techniques are effective, however, they involve significant time penalties. In this work, a new modulated wave-form command shaping technique is proposed to enable concurrent hoisting and travel maneuvers. The time varying ordinary differential equation of motion is derived and used to determine the parameters and frequency of the proposed shaped-command. Assuming linear hoisting, the equation is solved analytically by assuming small changes in the time varying terms. This approach results in some error which can be corrected by using pattern search optimization technique. It is shown that, the proposed method is capable of eliminating the travel and residual oscillations for different maneuvers involving linear hoisting. Performance is simulated numerically and validated experimentally on a scaled model of an overhead crane.
Sensitivity of Array-Like and Optimized Wind Farm Output to Key Factors and Choice of Wake Models
Authors: Tong Weiyang , Chowdhury Souma , Mehmani Ali , Zhang Jie , Messac Achille
Published: February 2014

The creation of wakes, with unique turbulence characteristics, downstream of turbines significantly increases the complexity of the boundary layer flow within a wind farm. In conventional wind farm design, analytical wake models are generally used to compute the wake-induced power losses, with different wake models yielding significantly different estimates. In this context, the wake behavior, and subsequently the farm power generation, can be expressed as functions of a series of key factors. A quantitative understanding of the relative impact of each of these factors is paramount to the development of more reliable power generation models; such an understanding is however missing in the current state of the art in wind farm design. In this paper, we quantitatively explore how the farm power generation, estimated using four different analytical wake models, is influenced by the following key factors: (i) incoming wind speed, (ii) land configuration, and (iii) ambient turbulence. The sensitivity of the maximum farm output potential to the input factors, when using different wake models, is also analyzed. The extended Fourier Amplitude Sensitivity Test (eFAST) method is used to perform the sensitivity analysis. The power generation model and the optimization strategy is adopted from the Unrestricted Wind Farm Layout Optimization (UWFLO) framework. In the case of an array-like turbine arrangement, both the first-order and the total-order sensitivity analysis indices of the power output with respect to the incoming wind speed were found to reach a value of 99%, irrespective of the choice of wake models. However, in the case of maximum power output, significant variation (around 30%) in the indices was observed across different wake models, especially when the incoming wind speed is close to the rated speed of the turbines.
On Some Properties of the Mechanical Topology That Affect Parallel Solvers
Authors: Tasora Alessandro , Negrut Dan
Published: February 2014

The efficiency of parallel solvers for large multibody systems is affected by the topology of the network of constraints. In the most general setting, that is the case of problems involving contacts between large numbers of parts, the mechanical topology cannot be predicted a priori and also changes during the simulation. Depending on the strategy for splitting the computational workload on the processing units, different types of worst case scenarios can happen. In this paper we discuss a few approaches to the parallelization of multibody solvers, ranging from the fine-grained parallism on GPU to coarse-grained parallelism in clusters, and we show how their bottlenecks are directly related to some graph properties of the mechanical topology. Drawing on the topological analysis of the constraint network and its splitting, lower bounds on the computational complexity of the solver methods are presented, and some guidelines for limiting the worst-case scenarios in parallel algorithms are put forward.