bluuebunny/crossref_metadata_2025 huggingface dataset:
Maintainability Evaluation Based on the Product Disassembly Analysis
Authors: Wu Nan , Peng Qingjin
Published: July 2010

Maintainability is an important product characteristic related to the product life-time operation and the operation cost. Maintainability increases product’s serviceability and decreases product’s maintenance cost. Product disassembability is one of the key factors of product maintainability. A disassembly is normally required for product repairing, product remanufacturing, components reusing, and materials recycling in the product life-cycle management. A better disassembly plan will improve efficiency of these processes for product maintainability. This paper introduces the product maintainability analysis based on the disassembly sequence evaluation. An AND/OR graph based disassembly analysis and the cost-based evaluation are introduced for the evaluation of product maintainability. The proposed data structure and methods are discussed. The system developed is demonstrated using a case study.
Validation and Identification of Optimal Fixturing Scheme Using VR
Authors: Thukaram Santosh Kumar , Peng Qingjin , Balikrishnan Subramaniam
Published: July 2010

Fixtures are important components in manufacturing systems. Fixturing changes because of manufacturing changing from mass production to production in smaller batches and higher variety of products. Computer-aided fixture design (CAFD) systems automate the process of fixture design and verification. Research work has mainly concentrated either on automating the CAFD process or on making it user-friendly and interactive. However a final fixturing scheme may not be optimal because different users may need fixtures to meet different requirements, this paper proposes a conceptual module for the fixture validation to compare, test and analyze various combinations of fixturing elements. A fixture validation model is developed using a virtual reality (VR) system to support the idea presented in this paper.
Response Surface Algorithms for Engine Mount Optimization in Motorcycles
Authors: Kaul Sudhir , Dhingra Anoop K.
Published: July 2010

This paper presents a Response Surface Modeling (RSM) approach for solving the engine mount optimization problem for a motorcycle application. A theoretical model that captures the structural dynamics of a motorcycle engine mount system is first used to build the response surface model. The response surface model is then used to solve the engine mount optimization problem for enhanced vibration isolation. Design of Experiments (DOE), full factorial and fractional factorial formulations, are used to construct the governing experiments. Normal probability plots are used to determine the statistical significance of the variables and the significant variables are then used to build the response surface. The design variables for the engine mount optimization problem include mount stiffness, position vectors and orientation vectors. It is seen that RSM leads to a substantial reduction in computational effort and yields a simplified input-output relationship between the variables of interest. However, as the number of design variables increases and as the response becomes irregular, conventional use of RSM is not viable. Two algorithms are proposed in this paper to overcome the issues associated with the size of the governing experiments and problems associated with modeling of the orientation variables. The proposed algorithms divide the design space into sub-regions in order to manage the size of the governing experiments without significant confounding of variables. An iterative procedure is used to overcome high response irregularity in the design space, particularly due to orientation variables.
Study of Alternative Strategies to the Task Clarification Activity of the Market-Pull Product Development Process Model
Authors: Motte Damien
Published: July 2010

A very large majority of the current product development process models put forward in textbooks present a homogenous structure, what Ulrich & Eppinger [1] call the market-pull model, presented as a generic one, while other possible product development process models are merely seen as variants. This paper focuses on the task clarification and derived activities (mainly the systematic search for customer needs through market study and the supplementary development costs it entails) and investigates two alternative strategies that are not derived from the generic process model. The first alternative is the market-pull model without an extensive task clarification. The second is the application of the so-called expeditionary marketing strategy. With the help of simplified analytic modeling, the conditions for which these alternatives are as efficient as the generic process model are discussed. This advocates the development of more flexible process models.
Cost Modeling of Flexible Assembly Systems
Authors: Yang Yingxia , Kirchain Randolph , Roth Richard , Arinez Jorge , Biller Stephan , Spicer J. Patrick
Published: July 2010

Flexible assembly systems have emerged as a key manufacturing strategy in many industries, such as automotive, electronic components and computers, to respond to stronger market competition and greater product proliferation. As more companies install flexible assembly systems, design and planning decisions for such flexible systems have to be considered together with other factors besides market demand and competitive forces. This paper presents a cost analysis tool that estimates the cost of flexible assembly lines. Specifically, it provides the capability to study the production of a given set of products while evaluating the impact of different flexibility strategies on total assembly cost. A mathematical description of the model is given, followed by a case study demonstrating its application to strategic decisions during the early planning stages of assembly system design.
Universal Behavior for Characteristic Curve of Immunomagnetic Reduction Assay With Aid of Biofunctionalized Magnetic Nanoparticles
Authors: Hong Chin-Yih , Yang Shieh-Yueh , Horng Herng-Er , Chieh Jen-Jie , Yang Hong-Chang
Published: July 2010

By biofunctionalizing magnetic nanoparticles with bioprobes, magnetic nanoparticles are able to specifically label bio-molecules. With the association between magnetic nanoparticles and bio-molecules, the mixed-frequency AC magnetic susceptibility generated with the physical rotation of individual magnetic nanoparticles under external AC magnetic fields is reduced. This detection technology is so-called immunomagnetic reduction (IMR) assay. In the experiment, several kinds of proteins and small-molecule chemicals were detected via IMR. The characteristic curves, i.e. the reduction versus the concentration of protein/chemical, for these proteins or chemicals can be scaled to one universal curve.
Reliable Design Optimization Under Aleatory and Epistemic Uncertainties
Authors: Samson Sundeep , Thoomu Sravya , Fadel Georges , Reneke James
Published: July 2010

In the engineering design community, decision making methodologies to select the “best” design from among feasible designs is one of the most critical part of the design process. As the design models become increasingly realistic, the decision making methodology becomes increasingly complex. That is, because of the realistic design models, more and more decisions are made under uncertain environments without making any unrealistic assumptions. A decision maker is usually forced to work with uncertainties of which some stochastic information is known (aleatory) or no information is known (epistemic). In this paper, we discuss both forms of uncertainties and their modeling methodologies. We also define risk as a random function of these uncertainties and propose a risk quantification technique. Existing methods to handle aleatory uncertainties are discussed and an alternative search based decision making methodology is proposed to handle epistemic uncertainties. We illustrate our decision making methodology using the side-impact crashworthiness problem presented by Gu, et.al. [1]. In addition to the aleatory uncertainties considered by these researchers, we model a couple of non-design variables as epistemic uncertainties in our decision problem. Lack of information of these epistemic uncertainties increases the complexity of the side-impact crashworthiness problem significantly. However, the proposed methodology helps to identify a robust design with respect to epistemic uncertainty.
Design of an Antagonistic Bistable Dielectric Elastomer Actuator Using the Bergstrom-Boyce Constitutive Viscoelastic Model
Authors: Chouinard Patrick , Proulx Sylvain , Lucking Bigue´ Jean-Philippe , Plante Jean-Se´bastien
Published: July 2010

Dielectric Elastomer Actuators (DEA) has great potential for low cost, high performance robotic and mechatronic devices. However, the reliability of these actuators remains an important issue when used in continuous strain applications. To improve actuators reliability, DEAs can be used in a binary or bistable manner where actuators flip between two stable positions, thus maintaining one of two equilibrium states without any electrical energy input. This paper presents an antagonistic bistable DEA concept using a single, planar polymer film that can lead to compact high force multilayered actuators. The system is made bistable by the addition of carbon fiber leaf springs designed to maximize actuator strain output. The strong viscoelastic nature of the chosen polymer film significantly affects the system’s output force and is accounted for in the Bergstrom-Boyce material model. The model shows good agreement with experimental stress relaxation curves and is used to set the leaf springs’ force curve. Experimental results have shown that the acrylic polymer film’s (VHB 4905) strong viscoelastic nature limits the actuator speed at ∼ 0.9 mm/s; at higher speeds, the leaf springs cannot be matched with the proposed concept. The study also demonstrates that the proposed antagonistic actuator configuration is an interesting solution to provide reliable bistable actuation for compact structures and that developing polymer films with low viscoelasticity is key for optimal performance.
Design of a Binary Needle Manipulator Using Elastically Averaged Air Muscles for Prostate Cancer Treatments
Authors: Proulx Sylvain , Chouinard Patrick , Lucking Bigue´ Jean-Philippe , Plante Jean-Se´bastien
Published: July 2010

Affecting 1 out of 8 subjects in the U.S., prostate cancer is the most common form of cancer in men. Current medical procedures could be improved by the development of an MRI compatible (Magnetic Resonance Imaging) needle manipulator system, to precisely reach small tumors (<5 mm) inside the prostate. This paper presents and analyzes the potential of such a needle manipulator concept, based on hyper-redundant binary air muscles, all controlled by MRI compatible valves (e.g. piezoelectric or dielectric elastomer actuators). The proposed manipulator uses 12 polymer air muscles, each driven by 2 different actuation pressures, offering a total of 4096 (212) discrete needle positions. Based on a hyperelastic continuum mechanics air muscle model, a theoretical manipulator design is used to evaluate clinically-relevant design metrics, such as size, stiffness, workspace, accuracy and sensitivity. In this model, the manipulator’s equilibrium configuration (for a given set of input pressures and applied forces) is found by minimizing the system’s potential energy. The model capability is verified experimentally by a one degree of freedom (DOF) prototype. Simulation results show that the proposed elastically averaged air muscle concept can meet all design requirements. In particular, the needle workspace of about 70 mm by 80 mm entirely covers the prostate area, where targets are accurately reachable within 0.7 mm. Also, the pneumatic actuators can generate high forces leading to a system stiffness of ∼4.6 N/mm at the needle tip. Such stiffness can adequately sustain the needle during insertion with minimal deflection to guaranty accurate positioning.
A Study of Different Metamodeling Techniques for Conceptual Design
Authors: Noon Christian , Winer Eliot
Published: July 2010

Many high fidelity analysis tools including finite-element analysis and computational fluid dynamics have become an integral part of the design process. However, these tools were developed for detailed design and are inadequate for conceptual design due to complexity and turnaround time. With the development of more complex technologies and systems, decisions made earlier in the design process have become crucial to product success. Therefore, one possible alternative to high fidelity analysis tools for conceptual design is metamodeling. Metamodels generated upon high fidelity analysis datasets from previous design iterations show large potential to represent the overall trends of the dataset. To determine which metamodeling techniques were best suited to handle high fidelity datasets for conceptual design, an implementation scheme for incorporating Polynomial Response Surface (PRS) methods, Kriging Approximations, and Radial Basis Function Neural Networks (RBFNN) was developed. This paper presents the development of a conceptual design metamodeling strategy. Initially high fidelity legacy datasets were generated from FEA simulations. Metamodels were then built upon the legacy datasets. Finally, metamodel performance was evaluated based upon several dataset conditions including various sample sizes, dataset linearity, interpolation within a domain, and extrapolation outside a domain.
Optimization and Design of a Cable Driven Upper Arm Exoskeleton
Authors: Agrawal Sunil K. , Dubey Venketesh N. , Gangloff John J. , Brackbill Elizabeth , Sangwan Vivek
Published: July 2010

This paper presents the design of a wearable upper arm exoskeleton that can be used to assist and train arm movements of stroke survivors or subjects with weak musculature. In the last ten years, a number of upper-arm training devices have emerged. However, due to their size and weight, their use is restricted to clinics and research laboratories. Our proposed wearable exoskeleton builds upon our extensive research experience in wire driven manipulators and design of rehabilitative systems. The exoskeleton consists of three main parts: (i) an inverted U-shaped cuff that rests on the shoulder, (ii) a cuff on the upper arm, and (iii) a cuff on the forearm. Six motors, mounted on the shoulder cuff, drive the cuffs on the upper arm and forearm, using cables. In order to assess the performance of this exoskeleton, prior to use on humans, a laboratory test-bed has been developed where this exoskeleton is mounted on a model skeleton, instrumented with sensors to measure joint angles and transmitted forces to the shoulder. This paper describes design details of the exoskeleton and addresses the key issue of parameter optimization to achieve useful workspace based on kinematic and kinetic models.
Simulation of Singly and Doubly Clamped Nanotube Based NEMS Devices
Authors: Chen P. , Peng B. , Ding L. , Xu W. H. , Wang Y. Q. , Ke C. H.
Published: July 2010

In this paper a multiphysics simulation of nanotube based nano-electromechanical systems is reported. Assuming continuum mechanics, the nonlinear deformation of the nanotube is simulated using reduced order modeling method. In particular, we study singly and doubly clamped nanotubes under electrostatic actuation. The simulation emphasizes the prediction of the pull-in voltage of the device, a key design parameter. Moreover, the nonlinear behavior associated with finite kinematics (i.e., large deformations), neglected in previous studies, are investigated in detail. The multiphysics simulation results agree well with the theoretical predictions verifying that the numerical model is valid. The results show that nonlinear kinematics results in an important increase in the pull-in voltage of doubly clamped nanotube devices, but that it is negligible in the case of singly clamped devices. These models provide a guide on the effect of the various geometrical variables and insight into the design of novel devices.
A Comparative Study of Quantitative Scales to Populate Affordance Structure Matrices
Authors: Maier Jonathan R. A. , Sachs Rayann , Fadel Georges M.
Published: July 2010

The Affordance Structure Matrix (ASM) is a concept exploration and attention directing tool to enable designers to take advantage of the special properties of affordances, such as form dependence and polarity of positive and negative affordances. However, in an ASM, as in other popular matrix based tools, the entities being mapped (in the case of an ASM, affordances and components, respectively) are typically assumed to be of equal importance. In this paper we present a comparative study of various quantitative scales used to populate ASMs. By using these scales, we can capture the relative importance of different affordances, for example that cutting the user is more important to avoid than annoying the user with noise. Also, by using scales of increased granularity for populating the interior of an ASM, the relative strength of relationships between product components and individual components can be captured. For example, larger, heavier components have a stronger relationship with transportability than smaller, lighter components. The results of the comparison studies on the case study of a shaving razor show that a scale of negative ten through positive ten for populating the interior of the matrix is necessary to produce results which clearly rank all of the components in terms of helpful and harmful relationships. The results also show that the scale used for populating the interior of the matrix has a much stronger effect on the results than does the scale used for weighting the individual affordances. An electro-mechanical razor is used as the consumer product in the comparative study. Based on the results of the study, practical suggestions for redesigning the razor are also suggested.
Impedance Control of Manipulators With Heavy Payload for Spacecraft Rendezvous and Docking Simulators
Authors: Aghili Farhad
Published: July 2010

This paper presents a method to control a manipulator system grasping a rigid-body payload so that the motion of the combined system in consequence of external applied forces to be the same as another free-floating rigid-body (with different inertial properties). This allows zero-g emulation of a scaled spacecraft prototype under the test in a 1-g laboratory environment. The controller consisting of motion feedback and force/moment feedback adjusts the motion of the test spacecraft so as to match that of the flight spacecraft. The stability of the overall system is analytically investigated, and the results show that the system remains stable provided that the inertial properties of two spacecraft are different and that an upperbound on the norm of the inertia ratio of the payload to manipulator is respected. Important practical issues such as calibration and sensitivity analysis to sensor noise and quantization are also presented. Finally, experimental results are presented.
Tooth Surface Error Correction for Face-Hobbed Hypoid Gears
Authors: Fan Qi
Published: July 2010

Face-hobbing is a continuous generating process employed in manufacturing spiral bevel and hypoid gears. Due to machining dynamics and tolerances of machine tools, exact tooth surface geometry may not be obtained from the machining process using theoretical machine tool settings. Repeatable tooth surface geometric errors may be observed. The tooth surface errors will cause unfavorable displacement of tooth contact and increased transmission errors, resulting in noisy operation and premature failure due to edge contact and highly concentrated stresses. In order to eliminate the tooth surface errors and ensure precision products, a corrective machine setting technique is employed to modify the theoretical machine tool settings, compensating for the surface errors. This paper describes a method of correcting tooth surface errors for spiral bevel and hypoid gears generated by face-hobbing process using computer numerically controlled (CNC) hypoid gear generators. Polynomial representation of the universal motions of machine tool settings is considered. The corrective universal motion coefficients are determined through an optimization process with the target of minimization of the tooth surface errors. The sensitivity of the changes of tooth surface geometry to the changes of universal motion coefficients is investigated. A numerical example of a face-hobbed hypoid pinion is presented.
Developing a Robust System of Environmental Tools (RSET) to Improve Ecodesign Practice in the Automotive Sector
Authors: Andriankaja Hery , Bertoluci Gwenola , Vasilescu Claudiu` , Millet Dominique
Published: July 2010

This paper describes an ongoing research project related to the development of an interdependent system of tools for performing systemic and sustainable evaluation of environmental performance by the car parts manufacturer Faurecia. The approaches developed in this research are based on (1) establishing a robust system for assessing environmental impacts through a set of dynamic indicators, (2) the exploitation of this set of indicators by the design team using appropriate means put at their disposition via a new organization. These two aspects are the bases of this article, which concludes by presenting a draft version of the system mock up with an evaluation result example.
An Application of a Generalized Life Cycle Cost Model to a Typical Pump From Industry
Authors: Waghmode L. Y. , Sahasrabudhe A. D.
Published: July 2010

The objective of this paper is to develop a methodology for effective implementation of life cycle costing (LCC) in design and procurement of repairable and non-repairable products. For this purpose, a generalized model for LCC of repairable and non-repairable products has been proposed. The equations of cost components of the proposed generalized model have been formulated for repairable systems based on the reliability and maintainability aspects to enable the life-time cost conscious design of such systems. The repairable systems typically have a life span of 10 to 20 years and experience multiple failures over their life span. The life cycle cost of a repairable system is significantly influenced by its reliability and maintainability. The life time energy and/or maintenance cost often dominate LCC for most of the repairable systems. Under the condition of constant failure rate the repairable system reliability is characterized by mean time between failures (MTBF) and maintainability by mean time to repair (MTTR). A higher value of MTBF and lower value of MTTR results into lower life cycle cost and therefore a due consideration to these factors is essential while designing repairable systems. The generalized LCC model presented in this paper will assist the designers to compare the life cycle cost of their different design alternatives at product design phase wherein most of the life cycle costs are committed. The developed generalized LCC model is applied to a typical repairable system, a pump from industry and the results obtained are presented.
Approximate Closed-Form Solutions for the Shift Mechanics of Rubber Belt Variators
Authors: Cammalleri Marco , Sorge Francesco
Published: July 2010

The mechanical behavior of V-belt variators during the speed ratio shift is different from the steady operation as a gross radial motion of the belt is superimposed to the circumferential motion. The theoretical analysis involves equilibrium equations similar to the steady case, but requires a re-formulation of the mass conservation condition making use of the Reynolds transport theorem. The mathematical model of the belt-pulley coupling implies the repeated numerical solution of a strongly non-linear differential system. Nevertheless, an attentive observation of the numerical diagrams suggests simple and useful closed-form approximations for the four possible working modes of any pulley, opening/closing, driver/driven, whose validity ranges over most practical cases. The present analysis focuses on the development of such simplified solutions, succeeding in an excellent matching with the numerical plots, and on the comparison of the theory with some experimental tests on a motorcycle variator, revealing a very good agreement.
An Empirical Evaluation of Novelty-SAPPhIRE Relationship
Authors: Srinivasan V. , Chakrabarti Amaresh
Published: July 2010

The research shown in this paper is to check whether a framework for designing: GEMS of SAPPhIRE as req-sol, developed earlier, can support in the designing of novel concepts. This is done by asking the questions: (a) Is there a relationship between the constructs of the framework and novelty? (b) If there is a relationship, what is the degree of this relationship? A hypothesis — an increase in the size and variety of ideas used while designing should enhance the variety of concepts produced, leading to an increase in the novelty of the concept space — is developed to explain the relationship between novelty and the constructs. Eight existing observational studies of designing sessions, each involving an individual designer solving a conceptual design problem by following a think aloud protocol are used for the analysis. The hypothesis is verified empirically using the observational studies. Results also show a strong correlation between novelty and the constructs of the framework; correlation value decreases as the abstraction level of the constructs reduces, signifying the importance of using constructs at higher abstraction levels especially for novelty.
Effective Analogical Transfer Using Biological Descriptions Retrieved With Functional and Biologically Meaningful Keywords
Authors: Cheong Hyunmin , Shu L. H.
Published: July 2010

While biology is well recognized as a good source of analogies for engineering design, the steps of 1) retrieving relevant analogies and 2) applying these analogies are not trivial. Our recent work translated the functional terms of the Functional Basis into biologically meaningful keywords that can help engineers search for and retrieve relevant biological phenomena for design, addressing step 1 above. This paper reports progress towards step 2: identifying and overcoming obstacles to effective analogical transfer and application of biological descriptions retrieved with functional and biologically meaningful keywords. This work revealed that the presence of, and ease of recognizing, causal relations (relationships between two actions where one causes another) in biological descriptions plays a key role in the quality of analogical transfers. We observed that novice designers found it difficult to correctly transfer analogies when they could not easily recognize the causal relations present in biological descriptions. Two major factors that rendered this recognition difficult were: 1) a large number of action words appearing in the descriptions, and 2) key action words being used in the passive voice. To overcome these factors, we propose a template that guides designers to 1) recognize the relevant causal relations in biological descriptions and 2) focus on the functional elements of the causal relations.
Evaluation of a Trapping Potential Measurement Technique for Optical Tweezers Using Simulations and Experiments
Authors: Balijepalli Arvind , LeBrun Thomas W. , Gorman Jason J. , Gupta Satyandra K.
Published: July 2010

A technique to measure the trapping force in an optical tweezers, without making any prior assumptions about the trap shape, has been extended to two-dimensions. The response of a trapped micro or nanoparticle to a step input is measured and then used to calculate the trapping force experienced by the particle as a function of its position in the trap. Langevin dynamics simulations have been implemented to evaluate the performance of this measurement method in two-dimensions and to evaluate whether the particle’s motion away from the measurement plane due to diffusion gives rise to an error in the trapping force measurement. Preliminary experimental results are also presented to demonstrate this method in the laboratory. This force measurement method provides insight into the trapping behavior of micro and nanoparticles in an optical trap beyond the region, close to the trap center, where the trapping force is assumed to vary linearly with the particle’s displacement. The measured trapping forces, from simulations and laboratory experiments, are then integrated to recover the shape of the optical trapping potential.
Transmission Error as Gear Noise Excitation
Authors: Henriksson Mats , Pang Yuet-Yan
Published: July 2010

Traditionally, transmission error (TE) has been used in order to asses the noise properties of gears. Measurements of gear noise for a complete truck gearbox have been used to correlate noise from a gear pair with the concept of calculated static transmission error as noise excitation. Two gear pairs with very similar macro geometry but different micro geometry was used. Both transmission error as excitation and the excitation proposed by P. Velex and M. Ajmi which is the difference between the loaded and unloaded transmission error, are compared with measured noise. The result shows that the difference between the loaded and unloaded TE correlates well with measure noise for gear pair A but no excitation correlates with the measurement result gear pair B. A big difference between gear pair A and B can be seen in the contact pattern. The contact pattern of gear pair B shows that despite a large tip relief, edge contact occurs where the tip relief starts. This can be one explanation to the lack of correlation between TE and the measurement result for gear pair B. Another explanation can be other excitations such as friction and bending moments. The results show the limitations of only considering transmission error when designing quiet gears.
Design Approaches for Wire Robots
Authors: Bruckmann Tobias , Mikelsons Lars , Brandt Thorsten , Hiller Manfred , Schramm Dieter
Published: July 2010

Wire robots consist of a movable end-effector which is connected to the machine frame by motor driven wires. Since wires can transmit only tension, positive wire forces have to be ensured. During workspace analysis, the wires forces need to be calculated. Discrete methods do not produce satisfying results, since intermediate points on the discrete calculation grids are neglected. Using intervals instead of points leads to reliable results. Formulating the analysis problem as a Constraint-Satisfaction-Problem (CSP) allows convenient transition to the synthesis problem, i.e. to find suitable designs for practical applications. In this paper, two synthesis approaches are employed: Design-to-Workspace (i.e. calculation of an optimal robot layout for a given workspace) and an extension called Design-to-Task (i.e. calculation of the optimal robot for a specific task). To solve these optimization problems, the paper presents approaches to combine the reliability and robustness of interval-based computations with the effectiveness of available optimizer implementations.
A Decision-Analytic Concept Selection for a Commercial System Using Objective Data to Model Uncertainty
Authors: Takai Shun , Razu Swithin S. , Banga Karan
Published: July 2010

This paper presents decision-analytic concept selection framework for a commercial system and an uncertainty modeling using objective data. The selection of a system concept for which a final system is designed and manufactured is a decision making process with incomplete information. Decision analysis is a prescriptive approach for decision making under uncertainty. While realizing that humans make decisions violating the expected utility axioms, decision analysis uses a set of tools to guide a decision maker toward an unbiased and rational decision making. The objective of this research is to propose a decision-analytic framework for commercial system concept selection, and an approach to utilize as much objective data as possible in the uncertainty modeling. Toward this objective, this paper construct cost distribution using case-based reasoning and market share distribution applying bootstrap to customers’ preference data obtained from conjoint analysis. The proposed approach is demonstrated in an illustrative example: a decision-analytic automobile concept selection.
A Design Method for Developing a Universal Product Family in a Dynamic Market Environment
Authors: Moon Seung Ki , McAdams Daniel A.
Published: July 2010

Innovative companies that generate a variety of products and services for satisfying customers’ specific needs are invoking and increasing research on mass-customized products, but the majority of their efforts are still focused on general consumers who are without disabilities. This research is motivated by the need to provide a basis of universal design guidelines and methods, primarily because of a lack of knowledge on disabilities in product design as well as methods for designing and evaluating products for everyone. Product family design is a way to achieve cost-effective mass customization by allowing highly differentiated products to be developed from a common platform while targeting products to distinct market segments. By extending concepts from product family design and mass customization to universal design, we propose a method for developing a universal product family to generate economical feasible design concepts and evaluating design feasibility with respect to disabilities within dynamic market environments. We will model design strategies for a universal product family as a market economy where functional module configurations are generated through market segments based on a product platform. A coalitional game is employed to model module sharing situations regarding dynamic market environments and decides which functional modules provide more benefit when in the platform based on the marginal contribution of each module. To demonstrate implementation of the proposed method, we use a case study involving a family of mobile phones.
An Ease-Off Based Method for Loaded Tooth Contact Analysis of Hypoid Gears Having Local and Global Surface Deviations
Authors: Kolivand M. , Kahraman A.
Published: July 2010

Manufacturing errors typically cause real (measured) spiral bevel and hypoid gear surfaces to deviate from the theoretical ones globally. Tooth surface wear patterns accumulated through the life span of the gear set are typically local deviations that are aggravated especially in case of edge contact conditions. An accurate and practical methodology based on ease-off topography is proposed in this study to perform loaded tooth contact analysis of spiral bevel and hypoid gears having both types of local and global deviations. It starts with definition of the theoretical pinion and gear tooth surfaces from the machine settings and cutter parameters, and constructs the theoretical ease-off and roll angle surfaces to compute unloaded contact analysis. Manufacturing errors and localized surface wear deviations are considered to update the theoretical ease-off to form a new ease-off surface that is used to perform a loaded tooth contact analysis according to the semi-analytical method proposed earlier. At the end, a numerical example with locally deviated surfaces is analyzed to demonstrate the effectiveness of the proposed methodology as well as quantifying the effect of such deviations on load distribution and the loaded motion transmission error.
The Wolfrom Gear Train: A Case of Highest-Complexity Related Modifications of the Tooth Meshing
Authors: Arnaudov Kiril , Karaivanov Dimitar
Published: July 2010

The Wolfrom gear is suitable for high speed ratios with an efficiency which is not optimal, but still acceptable. The version with single-rim satellites has significant design and technological advantages. However, the determination of the most appropriate modification coefficients poses a technical problem as the modifications are now related instead of being chosen independently. The geometrical calculations of the single-rim satellites version are performed in the paper. Speed ratio, number of teeth of the satellites, pressure angles and modification coefficients are determined. Advisable values for these parameters are given. As an example a specific design problem for the replacement of a three-stage planetary reducer (consisting of 15 gears) with a Wolfrom gear train (6 gears) the following calculations were performed.
Concept and Components for Disturbance Decoupling and Energy Harvesting
Authors: Dettmann Kai-Uwe , Marx Matthias , Kashi Keiwan , Nissing Dirk , So¨ffker Dirk
Published: July 2010

This contribution contains the conception, the components modeling, the realization, and first results for active disturbance decoupling including the experimentally checked ability of the concept for energy harvesting. The investigated mechanical structure consists mainly of a torsional spring. At one side of the spring the disturbances (time-dependent torques with varying frequencies) are driven by a position controlled hydraulic cylinder. The other side of the spring is locked and a force sensor is applied. Due to different torsion angles a torque between the left and right side of the torsion spring is induced. To eliminate or at least to reduce the torque in a passive system it is theoretically sufficient to adjust the stiffness of the spring situation-dependent, although this is practically not possible. For that reason an active disturbance control is presented here. The torque of the spring has to be controlled independently of the displacements at the right and left side. This sophisticated strategy is described in the following. In this contribution the concept and realization of a new active mechanism is realized by dividing the spring into two halves and inserting an electro-mechanical actuator. Hence, the active mechanism compensates the different torsion angles (resp. torques) by adjusting the rotor angle. The results of related test-rig experiments will be shown and the possibility to decouple the torques from each other, which can be interpreted as disturbances, is demonstrated. The strategy of active disturbance decoupling is based on the measured displacement of the hydraulic cylinder and the measured force. In chapter 2 the idea and conception of the test-rig is discussed and the realized solution is shown. The following chapter deals with the system model and especially with the idea of torque control. Furthermore the chosen disturbance profiles are shown and the effects of active decoupling are discussed. In the last chapter results of experimental tests for energy harvesting are given, showing principally the efficiency as well as the limits of todays technology.
A Stochastic Graph Grammar Algorithm for Interactive Search
Authors: Campbell Matthew I. , Rai Rahul , Kurtoglu Tolga
Published: July 2010

This paper presents a new search method that has been developed specifically for search trees defined by a generative grammar. Generative grammars are useful in design as a way to encapsulate the design decisions that lead to candidate solutions. Since the candidate solutions are not confined to a single configuration or topology and thus useful in conceptual design, they may be difficult to computationally analyze. Analysis is achieved in this method by querying the user. The user interaction is kept to a maximum of thirty pair-wise comparisons of candidates. From the data gathered from the comparisons, a stochastic decision making process infers what candidate solutions best meet the user’s preference. The method is implemented and applied to a grammar for tying neckties. It is shown through 21 user experiments and 4000 automated experiments that the method consistently finds solutions within the 99.8 percentile. The implications of this method for conceptual design are expounded on in the conclusions.
Modeling and Virtual Reality Realization of Coupled Processes in Integrated Open-Die Forging Plant
Authors: Yan Changya , Gao Feng , Chen Jie
Published: July 2010

A virtual plant, built in a computer by using computer graphic (CG) and Virtual Reality (VR), can model the precise and whole structure of an integrated manufacturing system and simulate its physical and logical behavior in operation. This paper aims to reveal the advanced modeling and VR realization methods in developing a virtual forging plant for automatic and programmed open-die forging processes. Two sub-models, component model and process model, compose the overall modeling architecture of a virtual integrated open-die forging plant. The coordinated motion simulation of the integrated system is realized through a kinematic modeling method. A compound stiffness modeling method is then developed to simulate the mechanical behavior in operation. The process simulation of the virtual plant is conducted on the basis of the above two modeling methods. A practical application example of virtual plant for integrated open-die forging process is presented towards the end.
The Design and Testing of RoboClam: A Machine Used to Investigate and Optimize Razor Clam-Inspired Burrowing Mechanisms for Engineering Applications
Authors: Winter Amos G. , Hosoi A. E. , Slocum Alexander H. , Deits Robin L. H.
Published: July 2010

Razor clams (Ensis directus) are one of nature’s most adept burrowing organisms, able to dig to 70cm at nearly 1cm/s using only 0.21J/cm. Ensis reduces burrowing drag by using motions of its shell to fluidize a thin layer of substrate around its body. Although these shell motions have an energetic cost, moving through fluidized rather than packed soil results in exponentially lower overall energy consumption. This paper describes the design and testing of RoboClam, a device that mimics Ensis digging methods to understand the limits of razor clam-inspired burrowing, how they scale for different environments and conditions, and how they can be transferred into engineering applications. Using a genetic optimization solver, we found that RoboClam’s most efficient digging motion mimicked Ensis shell kinematics and yielded a power law relationship between digging energy and depth of n = 1.17, very close to the ideal value of n = 1. Pushing through static soil has a theoretical energy-depth power law of n = 2, which means that Ensis-inspired burrowing motions can provide exponentially higher energy efficiency and nearly depth-independent drag resistance.
Motorcycle Dynamic Models for Virtual Rider Design and Cornering Analysis
Authors: Moreno Giner David , Manka Michal
Published: July 2010

In this paper, three motorcycle models of increasing complexity are introduced. The first, and most simple, can be considered an extension of the model developed by Neil Getz in which the non-holonomic constraints have been removed to take into account the sideslip in tires. Also, this model can be viewed as an extension of the popular bicycle model, widely used in analyzing car dynamics. It has been extended with an additional degree of freedom essential to study motorcycle dynamics: the roll angle. Such a model, simple yet detailed enough, will be used as the basis in the development of a virtual rider. The second model is much more complex than the previous one. It includes the real geometry of the steering system and circular tire profiles which greatly increases the size of the equations. This is a multibody model of a complete rigid motorcycle (i.e. it has no suspensions) consisting of 4 bodies: rear wheel, main frame, fork and front wheel. The last model incorporates the front and rear suspensions together with all the features of its predecessor. It has 13 degrees of freedom, 11 of the mechanical system and 2 of the tire relaxation equations. It will be used as a full model for simulation and rider validation. The models presented in this article have been developed using Maple mathematical software which allows symbolic manipulation of equations. Thus, with this set of models, one can study in depth the phenomena that govern motorcycle dynamics since all the equations are available symbolically.
Influence of Gear Rim Deflections on Planetary Gear Set Behavior
Authors: Ligata H. , Kahraman A. , Singh A.
Published: July 2010

In this study, results of an experimental and theoretical study on the influence of rim thickness of the ring gear on rim deflections and stresses, and planet load sharing of a planetary gear set are presented. Experimental study consists of measurement of ring gear deflections and strains for gear sets having various numbers of planets, different ring gear rim thicknesses as well as various carrier pin hole position errors. Root and hoop strain gauges and displacement probes are placed at various locations so that the variations due to external splines of the stationary ring gear can also be quantified. A family of quasi-static deformable-body models of the test gear planetary gear sets is developed to simulate the experiments. The predictions and the measurements are compared to assess the accuracy of the models within wide ranges of parameters. Influence of rim thickness on ring gear stresses and deflections and planet load sharing are quantified together with the interactions between the rim flexibility and the spline conditions. The results from this study confirm that the ring gear deflections and the ring gear support conditions must be included in the design process as one of the major factors.
Concept Diagramming Software for Engineering Design Support: A Review and Synthesis of Studies
Authors: Eng Nathan L. , Bracewell Rob H. , Clarkson P. John
Published: July 2010

Engineering design thinking combines concepts from heterogeneous sources like personal experience, colleagues, digital and hardcopy media. Despite this challenge, modes of thinking across levels of abstraction through multi-dimensional (spatial) representations are widely neglected in digital support systems. This paper aims to summarize lessons learned through years of experience with software tools that augment this visio-spatial conceptual thinking. This work cuts across disciplines to provide a needed, coherent starting point for other researchers to examine complex outstanding issues on a class of promising support tools which have yet to gain widespread popularity. Three studies are used to provide specific examples across design phases, from conceptual design to embodiment. Each study also focuses on an exemplar of diagrammatic software: the University of Cambridge Design Rationale editor (DRed), the Institute for Human Machine Cognition’s (IHMC) CmapTools and the Open University’s Compendium hypermedia tool. This synthesis reiterates how hypermedia diagrams provide many unique, valuable functions while indicating important practical boundaries and limitations. Future research proposed includes: a need to build more diagrammatic literacy into engineering practice, the need for more detailed studies with experts in industry and specific directions for refining the hypermedia diagram software interfaces.