bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Utilization and Integration of RFID Data Into Enterprise Information Systems Via WinRFID
Authors: Su Xiaoyong , Chu Chi-Cheng , Prabhu B. S. , Gadh Rajit
Published: May 2009

It is challengeable to utilize and integrate RFID data into current Enterprise Information Systems because high volume of RFID data is captured at high speed and the data are in heterogeneous formats. In this paper, we propose a “store and forward” and subscription-based integration approach in WinRFID Data Collector to solve the challenges. The Data Collector is a middleware which processes and delivers data to end application based on rules defined in subscription conditions. “Event Cycle” based data reporting defined in EPCglobal Application Level Event specification is analyzed. WinRFID subscription is proposed to provide real-time event notification. The data processing and integration capability of the Data Collector is measured and analyzed.
Real-Time Multibody Vehicle Dynamics Software for Virtual Handling Tests
Authors: Kim Sung-Soo , Ha Kyoungnam , Kim Dohyun , Tak Taeoh , Shin Seung-Eon
Published: May 2009

Real-time multibody vehicle dynamics software has been developed for virtual handling tests. The software can be utilized for hardware in the loop simulations and consists of three modules such as a graphical vehicle modeling preprocessor, real time dynamics solver, and virtual reality graphic postprocessor for virtual handling tests. In the graphical vehicle modeling preprocessor, vehicle hard point data for a suspension model are automatically converted into multibody vehicle model. In the real time dynamics solver, efficient subsystem synthesis method is used to create multibody equations of motion a subsystem by a subsystem. In the virtual reality graphic postprocessor, virtual proving ground environment has been also developed by using OpenGL for virtual handling tests. This software is written C and can be converted to the S-function as a plant model in the RT-LAB real time environment for HILS application.
Analysis and Evaluation of Reliability of Diesel Engine Based on Maintenance Records
Authors: Liu Yu , Huang Hong-Zhong , Miao Qiang , Zuo Ming J.
Published: May 2009

Evaluating reliability and finding the critical components of a diesel engine system is a very important process in quality improvement and new product design. In this paper, a series of reliability indexes were applied in diesel engine reliability evaluation based on maintenance records. Several methods including life cycle distribution and FMEA (Failure Mode and Effects Analysis) were also presented. At the end, a diesel engine (Model 6108ZQ) was used as a case study.
Stability and Stationary Response of a Skew Jeffcott Rotor With Geometric Uncertainty
Authors: Driot Nicolas , Berlioz Alain , Lamarque Claude Henri
Published: May 2009

The dynamical behavior of an asymmetrical Jeffcott rotor subjected to a base translational motion is investigated. As the geometry of the skew disk is not well defined, we introduce some randomness. This uncertainty affects a particular parameter in the time-variant motion equations. Consequently, the amplitude of the parametric excitation is a random parameter which leads us to investigate the robustness of the dynamics. The stability is first studied by introducing a transformation of coordinates (feasible in this case) making the problem simpler. Then, far away from the unstable area, the random forced steady state response is computed from the original motion equations. The Taguchi’s method is used to provide statistical moments of the forced response.
Large Deformation Triangular Plate Elements for Multibody Problems
Authors: Dmitrochenko Oleg , Mikkola Aki
Published: May 2009

In this paper, triangular finite elements based on the absolute nodal coordinate formulation are introduced. Triangular elements employ the Kirchhoff plate theory and can, accordingly, be used in thin plate bending problems. These elements can exactly describe arbitrary rigid body motion while their mass matrices are constant. Previous plate developments in the absolute nodal coordinate formulation have focused on rectangular elements that are difficult to use when arbitrary meshes need to be described. The elements introduced in this study have overcome this problem and represent an important addition to the absolute nodal coordinate formulation. The two elements introduced are based on Specht’s and Morley’s shape functions. The numerical solutions of these elements are compared with results obtained using the previously proposed rectangular finite element and analytical results.
Acoustic Emission and Elastohydrodynamic Film Thickness for Meshing of Spur and Helical Gear
Authors: Raja Hamzah R. I. , Mba D.
Published: May 2009

This paper presents experimental evidence of the correlation between Acoustic Emission (AE) activity and the specific film thickness (λ) for operational spur and helical gears. Whilst recording AE activity for a range of test conditions the specific film thickness was varied during operation by spraying liquid nitrogen onto the rotating gear wheel. It was noted that the AE activity reduced significantly as the theoretically estimated specific film thickness increased. It is concluded that the measurements of AE activity may offer an opportunity to quantify the level of asperity contact for meshing gears under a range of operating conditions.
PDQ (Product Data Quality): Quality Guaranteed Product Data Representation and Application to Shape Model
Authors: Kikuchi Yoshihito , Hiraoka Hiroyuki , Ohtaka Akihiko , Tanaka Fumiki , Kobayashi Kazuya G. , Soma Atsuto
Published: May 2009

Inappropriate data problems due to mismatching of product data quality are always possible in data communication and sharing. In this problem, the data is evaluated as valid within the original system and its initial usage, but problem brake out during the reuse phase of the same data. This delayed problem requires data repair or rework operation in the subsequent manufacturing process and results in significant economic loss. As cause, current product data is a dumb model and its quality is not guaranteed. The receiver system cannot identify whether the data has sufficient quality for reuse or not. Furthermore, manufacture’s advance notice of their request for data quality is impossible. This paper proposes an establishment of PDQ (product data quality) information for communication of data quality that can be used independently or in combination with product data. The PDQ information model presents qualitative measurements according to given criteria, and the measured portion of product data. Based on PDQ model, a PDQ-S (PDQ for shape data) model has been developed. For PDQ-S, industrial guidelines about shape data communication are systematically categorized as the baseline of guarantee. The PDQ model is intended to be independent and neutral from calculation algorithm of measurement. As the method of development, STEP (ISO 10303: Standard for the exchange of product model data) architecture was adopted and the PDQ model was developed as a resource of STEP standards. We show an example about combination of shape data and concerned quality guarantying data.
On the Accuracy and Computational Costs of the Absolute Nodal Coordinate and the Floating Frame of Reference Formulation in Deformable Multibody Systems
Authors: Dibold Markus , Gerstmayr Johannes , Irschik Hans
Published: May 2009

In the present paper, a comparison of the absolute nodal coordinate formulation (ANCF) and the floating frame of reference formulation (FFRF) is performed for standard static and dynamic problems, both in the small and large deformation regime. Special emphasis is laid on the converged solutions and a comparison to analytical and numerical solutions from the literature. In addition to the work of previous authors, the computational performance of both formulations is studied for the dynamic case, where detailed information is provided concerning the different effects influencing the single parts of the computation time. In case of the ANCF finite element, a planar formulation based on the Bernoulli-Euler theory is utilized, consisting of two position and two slope coordinates in each node only. In the FFRF beam finite element, the displacements are described by the rigid body motion and a small superimposed transverse deflection. The latter is described by means of two static modes for the rotation at the boundary and a user-defined number of eigenmodes of the clamped-clamped beam. In numerical studies, the accuracy and computational costs of the two formulations are compared for a cantilever beam, a pendulum and a slider-crank mechanism. It turns out that both formulations have comparable performance and that the choice of the optimal formulation depends on the problem configuration. Recent claims in the literature that the ANCF would have deficiencies compared to the FFRF thus can be refuted.
Dynamical Analysis of Shell Structures by Means of B-Spline Shape Functions
Authors: Carminelli Antonio , Catania Giuseppe
Published: May 2009

This paper presents a free vibration analysis of double curvature free form shaped shell structures using the B-spline shape functions approximation method. It is based on the Ritz method. The shell formulation is developed following the well known Ahmad degenerate approach including the effect of shear deformation. The assumed displacement field is described through non-uniform B-spline functions of any degree. The effect of locking is investigated and both reduced and modified quadrature integration rules are considered with the purpose of increasing the solution accuracy and diminishing the computational cost. Numerical simulation is reported for the evaluation of the eigensolution of plates, and of single and double curvature shells to test the effectiveness and the efficiency of the approach. The presence of spurious zero energy modes both at local and global level was investigated. The solutions are compared with other available analytical and numerical solutions, and discussed in detail.
Analysis of Steady Motions on Curved Tracks Using Multibody Models
Authors: Escalona Jose´ L. , Chamorro Rosario
Published: May 2009

In this paper a systematic procedure for evaluating the steady curving of railroad vehicles is developed. The equations of motion obtained using multibody dynamics and the elastic contact method are used to this end. The method proposed can deal with flange contact of the wheels. Two coordinate transformations are needed to evaluate the steady curving as an equilibrium position of the system instead of a periodic orbit. The stability of the motions is also evaluated by using a special eigenvalue analysis of the equations of motion. The procedure developed simplifies significantly the analysis of the curving performance of railroad vehicles without loosing accuracy or generality. The paper includes as a numerical example the steady motion of an unsuspended wheelset. The comparison of the numerical results with classical theories shows the accuracy of the method proposed.
Embodied Collaboration Support System for 3D Shape Evaluation by Using Network Virtual Reality
Authors: Okubo Masashi , Watanabe Tomio
Published: May 2009

In this paper, a collaboration support system for 3D shape evaluation by using network virtual reality is proposed on the basis of both studies in 3D shape evaluation and communication support in virtual space. Collaboration mainly consists of two tasks; one is each partner’s task that is performed by the individual, the other is communication with each other. Both of them are very important objectives for all the collaboration support system. The proposed system provides the two viewpoints for each task. One is the viewpoint of back side of user’s own avatar for the smooth communication. The other is that of avatar’s eye for 3D shape evaluation. Switching the viewpoints satisfies the task conditions for 3D shape evaluation and communication. The system basically consists of PC, HMD and sensors, and users can share the embodied interaction by observing interaction between their avatars in virtual space. However, the HMD and magnetic sensors, which are put on the users, would restrict the nonverbal communication. Then, we have tried to compensate the loss of nodding of partner’s avatar by introducing the speech-driven embodied interactive actor InterActor. Sensory evaluation by paired comparison of 3D shapes in the collaborative situation in virtual space and in real space and the questionnaire are performed. The result demonstrates the effectiveness of InterActor’s nodding in the collaborative situation.
Active Component Lower Limb Prosthetic Device Research: Concept and Design
Authors: Mattos Javier O. , Kane Evan D. , Voglewede Philip A.
Published: May 2009

This paper presents a possible prosthetic solution to excessive metabolic energy expended by transtibial (below the knee) amputees. This solution uses a four bar mechanism in conjunction with a spring, a motor, and a prosthetic foot as a lower limb prosthetic device. An optimization was previously performed on the mechanism parameters to mimic human ankle moments during normal walking. The cost function has been refined with the intent to reduce the required peak power input as well as to keep the link lengths of the four bar mechanism within an order of magnitude of each other. Design complications of the prototype that have arisen and likely resolutions are also included in this paper. Parts have been sized and justified based on likely size of the wearer, potential full-production costs of parts, and cost constraints.
Semi-Active Suspension Systems for Railway Vehicles Based on Magnetorheological Fluid Dampers
Authors: Wang D. H. , Liao W. H.
Published: May 2009

In this paper, a seventeen degree-of-freedom (DOF) model for a full scale railway vehicle integrated with the semi-active controlled magnetorheological (MR) fluid dampers in its secondary suspension system is proposed to cope with the lateral, yaw, and roll motions of the car body, trucks, and wheelsets. The governing equation considering the dynamics of the railway vehicle integrated with MR fluid dampers in the secondary suspension system and the dynamics of the rail track irregularities are developed. The Linear Quadratic Gaussion (LQG) control law using the acceleration feedback is adopted, in which the state variables are estimated from the measurable accelerations with a Kalman estimator. In order to evaluate how the performances of the railway vehicle system integrated with the semi-active controlled MR fluid dampers can be improved, the lateral, yaw, and roll accelerations of the car body, trucks, and wheelsets of a full scale railway vehicle integrated with MR fluid dampers, which are controlled (the semi-active) and uncontrolled (the passive on and passive off) respectively, are analyzed under the random track irregularities based on the established governing equations and the modelled track irregularities. The simulation results not only show the control effectiveness of the railway vehicle with the semi-active suspension system based on MR fluid dampers for railway vehicles, but also illustrate that the semi-active railway vehicle suspension system based on MR fluid dampers combines the merits of the passive on and passive off railway vehicle suspension systems.
Preliminaries for a Spherical Compliant Mechanism: Pseudo-Rigid-Body Model Kinematics
Authors: Jagirdar Saurabh , Lusk Craig P.
Published: May 2009

The kinematic portion of a pseudo-rigid-body model (PRBM) is developed as a generalization from planar to spherical mechanisms. The topology of the spherical compliant segment and its rigid-body equivalent are derived from planar models by analogy. The nomenclature for the spherical PRBM is chosen to facilitate comparison with the planar PRBM. The motion of the compliant segment is calculated using FEA and PRBM parameters are determined. The characteristic radius and parametric angle coefficient are found to decrease as the angle subtended by the beam increases. The parameterization limit increases with increasing beam angle. The spherical PRBM is identical to the planar PRBM in the limiting case when beam angles become very small.
From a 3-DOF Parallel Redundant ARCHI Robot to an Auto-Calibrated ARCHI Robot
Authors: Corbel David , Company Olivier , Pierrot Franc¸ois
Published: May 2009

This paper presents the modification of an existing planar parallel mechanism from actuation redundancy to kinematic redundancy. An additional joint is introduced in the initial mechanism in order to make the modification and to auto-calibrate the mechanism by measuring the displacement of this additional joint. The first simulation results are presented and a discussion about it is proposed as a conclusion.
Floquet Experimental Modal Analysis for System Identification of Linear Time-Periodic Systems
Authors: Allen Matthew S.
Published: May 2009

A variety of systems can be faithfully modeled as linear with coefficients that vary periodically with time or Linear Time-Periodic (LTP). Examples include anisotropic rotorbearing systems, wind turbines, satellite systems, etc… A number of powerful techniques have been presented in the past few decades, so that one might expect to model or control an LTP system with relative ease compared to time varying systems in general. However, few, if any, methods exist for experimentally characterizing LTP systems. This work seeks to produce a set of tools that can be used to characterize LTP systems completely through experiment. While such an approach is commonplace for LTI systems, all current methods for time varying systems require either that the system parameters vary slowly with time or else simply identify a few parameters of a pre-defined model to response data. A previous work presented two methods by which system identification techniques for linear time invariant (LTI) systems could be used to identify a response model for an LTP system from free response data. One of these allows the system’s model order to be determined exactly as if the system were linear time-invariant. This work presents a means whereby the response model identified in the previous work can be used to generate the full state transition matrix and the underlying time varying state matrix from an identified LTP response model and illustrates the entire system-identification process using simulated response data for a Jeffcott rotor in anisotropic bearings.
Multi-Dimensional Harmonic Balance Applied to Rotor Dynamics
Authors: Guskov Mikhail , Sinou Jean-Jacques , Thouverez Fabrice
Published: May 2009

A large number of technical systems feature multi-frequency dynamical behavior. Multiple shaft rotating machinery, subject to simultaneous unbalances spinning at different speeds is a particular case of such systems. Common methods of steady state solution are not valid when the addressed systems have non-linear properties. This study presents a generalized version of harmonic balance coupled with arc-length continuation, developed in order to treat the dynamics of a dual shaft test rig provided with an inter-shaft bearing. The non-linearities are brought about by the presence of rolling element bearings with radial clearance. Numerically, the non-linear terms are taken into account via an AFT (alternating frequency-time domain) procedure, involving multi-dimensional FFT. The numerical results show the presence of response peaks corresponding to the rig’s eigenmodes predicted by linear eigensolution and from experiments. The overall behavior is consistent with the counter-rotating character of the machine operation. Non-linear phenomena due to bearings are also observed, especially the stiffening shape of peaks and apparent pedestal anisotropy involving the presence of backward whirling components in the system’s motion.
Some Effects of Gear Eccentricities on Automotive Rattle Noise
Authors: Perret-Liaudet Joe¨l , Rigaud Emmanuel
Published: May 2009

This study deals with the problem of automotive gear rattle noise, primary caused by the engine torque fluctuations. Even if the rattling phenomenon has no consequence on reliability, it may be particularly annoying for vehicle interior sound quality and acoustic comfort. Gear rattle noise results from vibro-impacts that may occur on unloaded gears under excessive fluctuations of the engine torque and driveline dynamic responses. It is reasonable to assume very short time duration for impacts between teeth due to rattle. Then, the main parameters which govern this kind of vibrations are the restitution coefficient introduced for impact modeling, the drag torque acting on the free running wheel during its free flight motion, its inertia and the excitation source which can be modeled by an imposed displacement. This excitation source is often modeled as a harmonic or, sometimes, periodic excitation related to the acyclism behavior of the engine torque fluctuation, at twice the rotation frequency of the primary input shaft. The aim of this study is to deal on several effects of the gear eccentricities considered first as a superimposed periodic excitation source and second as a time varying backlash source. For this end, a simple non-linear oscillator is introduced, based on restitution coefficient for impact modeling. The parameters studied are the operating rotation speed of the input shaft, the inertia of the free running wheel, the drag torque, and the eccentricities compared to the acyclism source. Results are presented through dimensionless parameters.
CRONE Observer of Nonlinear SISO Systems
Authors: Lanusse Patrick , Sabatier Jocelyn , Merveillaut Mathieu
Published: May 2009

CRONE control, robust control methodology based on fractional differentiation, is applied to state observer design. State observation can indeed be viewed as a regulation problem given that the goal of a state observer is to cancel the observation error in spite of measurement noise, disturbances and plant perturbations. This conclusion has been used recently to define a new class of state observers known in the literature as “dynamic observers” or “input-output observer”. It is based on the observation error dynamic feedback. In this paper, this idea is used to define the CRONE observer design methodology for nonlinear SISO systems. As for CRONE control, fractional differentiation in the definition of an equivalent open loop transfer function permits the reduction of the number of parameters to be optimised.
Dynamical Behavior of a Rotor Under Rotational Random Base Excitation
Authors: Bachelet Lucie , Driot Nicolas , Ferraris Guy , Poirion Fabrice
Published: May 2009

This paper investigates the dynamical behavior of a rotor under a random rotational base excitation, which is assumed to be a stationary and ergodic truncated Gaussian white noise. As the base motion is a rotation, the equations of motion present both internal and external random excitations. The stability of the rotor is then studied by computing the largest Lyapunov exponent with an iterative formula. Then, the power spectrum density of the stationary forced response is obtained from a Monte Carlo simulation. Finally, we perform a comparative analysis on the influence of the required number of modal shapes to describe accurately the response.
On the “Snubbing” Mechanism for Reducing Blade Vibration
Authors: Bachschmid Nicolo` , Pennacchi Paolo , Pesatori Emanuel , Turozzi Giorgio
Published: May 2009

Blade vibration reduction is an important task in high performance turbomachinery. One of the ways for obtaining this result is to limit the vibration amplitude at the blade tip by leaving a small gap between the shrouds of adjacent blades. In the vibration modes of the blade row in which the relative displacement between adjacent blades exceeds the gap, contact occurs between the blade tips, the relative motion is restricted and energy is dissipated during the contact. This is called the snubbing mechanism. In this paper a simplified model of blade rows in which the snubbing mechanism can occur is set up and numerical integration in time domain furnishes the time histories of the vibrations of the blades. The level of vibration reduction in the different modes that could be excited by the fluid flow is then evaluated. Unlucky combinations of parameters in the system can effect also a magnification instead of a reduction of the vibration amplitudes. Experimental results on single blades are needed to tune the parameters of the system, and to validate the proposed model and the obtained results.
Generation of Straight-Line Rigid-Body Displacement Using Coordinated Peaucellier Cells
Authors: Nelson Carl A.
Published: May 2009

Linkages are presented which generate straight-line motion of a rigid body. Typical mechanisms of this type (e.g. scissors lift or pantograph) have fixed pivots beneath the moving platform. The linkages presented here have remotely located fixed pivots and allow a range of platform motion which extends both above and beneath the line of the fixed pivots. Both exact and approximate solutions are presented, based on the Peaucellier straight-line linkage, and a synthesis example is given.
An Experimental Study of Subcritical Bifurcations in Milling
Authors: Radhakrishnan Anupam , Edes Ben T. , Mann Brian P.
Published: May 2009

The focus of the current paper is an experimental investigation of subcritical bifurcations in milling. Several researchers have reported results indicating that the secondary Hopf bifurcations of turning processes are subcritical. However, fewer results are available for milling — especially results that provide any substantial experimental evidence. Here, the experimental cutting tests were performed on a relatively long aluminum workpiece. The atypical length of the work piece will be used so that the depth of cut may be slowly increased or decreased during the cutting process. This provides visual evidence of hysteresis in the bifurcation diagram and the existence of multiple stable periodic solutions. The importance of this exploratory experimental effort is that multiple attractors may co-exist (stable periodic solutions) for the same cutting speed and depth of cut, but only one of these solutions would be the chatter free case. An important outcome from these results is that a small perturbation in the desirable stable solution near the borders of the stability diagram could result in a jump to the unstable cutting condition.
Initialization of Fractional Differential Equations: Background and Theory
Authors: Lorenzo Carl F. , Hartley Tom T.
Published: May 2009

It has been known that the initialization of fractional operators requires time-varying functions, a complicating factor. This paper simplifies the process of initialization of fractional differential equations by deriving Laplace transforms for the initialized fractional integral and derivative that generalize those for the integer-order operators. This paper provides background on past work in the area and determines the Laplace transforms for initialized fractional integrals of any order and fractional derivatives of order less than one. A companion paper in this conference extends the theory to higher order derivative operators and provides application insight.
Multiobjective Collaborative Robust Optimization (McRO) With Interval Uncertainty and Interdisciplinary Uncertainty Propagation
Authors: Li Mian , Azarm Shapour
Published: May 2009

Real-world engineering design optimization problems often involve systems that have coupled disciplines with uncontrollable variations in their parameters. No approach has yet been reported for the solution of these problems when there are multiple objectives in each discipline, mixed continuous-discrete variables, and when there is a need to account for uncertainty and also uncertainty propagation across disciplines. We present a Multiobjective collaborative Robust Optimization (McRO) approach for this class of problems that have interval uncertainty in their parameters. McRO obtains Multidisciplinary Design Optimization (MDO) solutions which are as best as possible in a multiobjective and multidisciplinary sense. For McRO solutions, the sensitivity of objective and/or constraint functions is kept within an acceptable range. McRO involves a technique for interdisciplinary uncertainty propagation. The approach can be used for robust optimization of MDO problems with multiple objectives, or constraints, or both together at system and subsystem levels. Results from an application of the approach to a numerical and an engineering example are presented. It is concluded that the McRO approach can solve fully coupled MDO problems with interval uncertainty and can obtain solutions that are comparable to an all-at-once robust optimization approach.
A Point Membership Classification for Sweeping Solids
Authors: Erdim Hu¨seyin , Ilies¸ Horea
Published: May 2009

Sweeps are considered to be one of the basic representation schemes in solid modeling, and have numerous applications in very diverse fields ranging from engineering design and manufacturing to computer graphics. Despite their prevalence, many properties of the general sweeps are not well understood. Furthermore, boundary evaluation algorithms for 3-dimensional solid objects currently exist only for reasonably simple objects and motions. One of the main reasons for this state of affairs is the lack of a generic point membership test for sweeps. In this paper we describe a point membership classification (PMC) for sweeping solids of arbitrary complexity moving according to one parameter affine motions such that the initial and final configurations of the moving object do not intersect. Our PMC test is defined in terms of inverted trajectory tests against the original geometric representation of the generator object. This PMC test provides complete geometric information about the set swept by the 3-dimensional moving object, and can play a fundamental role in sweep boundary evaluation and trimming algorithms, as well in a number of practical applications such as contact analysis of higher pairs in design and manufacturing. Since our PMC is formulated in terms of intersections between inverted trajectories and the generator, it can be implemented for any geometric representation that supports curve-solid intersections.
Observer Design for Nonlinear Systems With Time Periodic Coefficients Via Normal Form Theory
Authors: Zhang Yandong , Sinha S. C.
Published: May 2009

For most complex dynamic systems, it is not possible to measure all system states in a direct fashion. Thus for dynamic characterization and controller design purposes, it is often necessary to design an observer in order to get an estimate of those states which cannot be measured directly. In this work, the problem of designing state observers for free systems with time periodic coefficients is addressed. For linear time-periodic systems, it is shown that the observer design problem is the duality of the controller design problem. The state observer is constructed using a symbolic controller design method developed earlier using the Chebyshev expansion technique. For the nonlinear time periodic systems, the observer design is investigated using the Poincare´ normal form technique. The local identity observer is designed by using a set of near identity coordinate transformations which can be constructed in the ascending order of nonlinearity. These observer design methods are implemented using a symbolic computational algorithm and several illustrative examples are given to show the effectiveness of the methods.
Design of a Compliant Endoscopic Suturing Instrument
Authors: Cronin James A. , Frecker Mary , Mathew Abraham
Published: May 2009

This paper outlines the development and initial optimization of a compliant endoscopic suturing instrument. The developing field of Natural Orifice Transluminal Endoscopic Surgery requires innovative instruments to meet the size limitations inherent in this type of minimally invasive surgery; using compliant mechanisms is proposed as one method of meeting this requirement. Three initial compliant designs were created, modeled, and compared for a distal opening of 10 mm. Restricting these designs so that they must fit within a 3.3 mm working channel is currently unique in endoscopic suturing instruments. A design that utilizes contact for stress relief and intertwining parts for added deflection was selected from the three. ANSYS® was used to aid in graphical optimization to maximize the jaw opening and maximize the puncture force of the selected design. The best geometry has a distal opening of 13.8 mm at the tips and can supply a puncturing force of 6.33 N. A prototype has been machined using the optimized dimensions and is ready to be tested. This initial study in compliant suturing instrument designs has revealed response patterns for the chosen geometries that will lead to further refinements and improvements in future models.
Approximated Unimodal Region Elimination Based Global Optimization Method for Engineering Design
Authors: Younis Adel , Xu Ruoning , Dong Zuomin
Published: May 2009

Computer analysis and simulation based design optimization requires more computationally efficient global optimization tools. In this work, a new global optimization algorithm based on design experiments, region elimination and response surface model, namely Approximated Unimodal Region Elimination Method (AUREM), is introduced. The approach divides the field of interest into several unimodal regions using design experiment data; identify and rank the regions that most likely contain the global minimum; form a response surface model with additional design experiment data over the most promising region; identify its minimum, remove this processed region, and move to the next most promising region. By avoiding redundant searches, the approach identifies the global optimum with reduced number of objective function evaluations and computation effort. The new algorithm was tested using a variety of benchmark global optimization problems and compared with several widely used global optimization algorithms. The experiments results present comparable search accuracy and superior computation efficiency, making the new algorithm an ideal tool for computer analysis and simulation black-box based global design optimization.
A Design Strategy for Collaborative Decision Making in a Distributed Environment
Authors: Chen Zhiqiang , Siddique Zahed
Published: May 2009

In most instances it is necessary to partition a product realization process into a set of design activities. Design decisions are an important type of design activity. In order to ensure that information flows among different design activities are achieved without difficulty, uniform representation of the information is necessary. A design activity template and a solution template are presented in this paper to support the information flow in a design process. Activity template provides an option to describe the design problem so that engineers know exactly what kind of design decision is preferable. Solution template provides an option to describe the design solution. The paper also introduces an approach to manage and deliver design freedom from one engineering team to the other. In mechanical design, it is essential to give engineers a feasible design space so that they can choose the design solutions that best satisfy the design problem. A chip design example is used to illustrate the different concepts presented in this paper for collaborative decision making.
Viscoelastic Materials With Magnetically-Controllable Properties for Vibration Damping and Isolation
Authors: Bruch Daniel E. , Morey William P. , Anderson Eric H.
Published: May 2009

Viscoelastic Materials (VEMs) are in widespread use for vibration damping and isolation. Magnetorheological (MR) fluid devices are also increasingly used for vibration control. MR fluids are suspensions of metal particles in various carrier fluids that have properties controllable by imposition of a magnetic field, using mechanisms that suggest analogous manipulation of properties in more solid carrier or base materials. This paper describes a research effort that studied the properties of composite or compound materials that we call MR-VEM. Compared to traditional VEM, the material offers the opportunity to change properties — at a minimum, the stiffness, and to a lesser extent material damping — by application of magnetic fields. Properties can be manipulated with a DC or AC field. Magnetic design studies for MR-VEM compounds are described. The paper focuses on the experimental characterization of dynamic performance of MR-VEM devices for use in vibration isolation systems. Two properties were used as the basis for distinguishing samples: particle fill factor, that is the volume ratio of MR particles to the base VEM, and the magnitude of magnetic field applied while curing the MR-VEM elements. Applied magnetic field was also varied during testing. The compound material performance is studied through a range of experiments. Test data showing a factor of five stiffness adjustability are presented. Limitations imposed by the size of required magnetic components and by material heating are quantified and discussed. Overall, the material shows promise for applications requiring adjustability in effective stiffness. The paper concludes by considering actuation with the materials.
Switching Dynamics of a Periodically Forced Discontinuous System With an Inclined Boundary
Authors: Luo Albert C. J. , Rapp Brandon M.
Published: May 2009

This paper presents the switching dynamics of flow from one domain into another one in the periodically driven, discontinuous dynamical system. The simple inclined straight line boundary in phase space is considered as a control law for the dynamical system to switch. The normal vector-field product for flow switching on the separation boundary is introduced, and the passability condition of flow to the discontinuous boundary is presented. The sliding and grazing conditions to the separation boundary are presented as well. Using mapping structures, periodic motions of such a discontinuous system are predicted, and the local stability and bifurcation analysis are carried out. Numerical illustrations of periodic motions with grazing to the boundary and/or sliding on the boundary are given, and the normal vector fields are illustrated to show the analytical criteria.
A Customer-Driven Approach to One-of-a-Kind Product Design
Authors: Song Huijun , Xue Deyi , Tu Yiliu
Published: May 2009

This research addresses the issues to identify the optimal product design based on individual customer requirements in one-of-a-kind production (OKP). In this work, a function decomposition approach is introduced for modeling the variations of design functions, configurations, and parameters in generic OKP product families. Requirements of individual customers are modeled at two different levels: function level and technical level. Customized OKP products are created from the generic OKP product families based on customer requirements. The optimal product design is identified from feasible design candidates through optimization. An industrial case study is given to demonstrate the effectiveness of the introduced approach.
Bending Strength of Carburized Forged Spur Gear
Authors: Yamanaka Masashi , Miwa Shinji , Inoue Katsumi , Kawasaki Yoshiki
Published: May 2009

This paper deals with the evaluation of influence of the manufacturing methods precision forging and conventional hobbing on the bending fatigue strength of carburized gears. The forging has advantages in productivity and strength. The forged gear has a continuous directed fiber flow which runs along the gear profile. To clarify the effect of strength enhancement, a bending fatigue test is performed for the forged and the hobbed gears. The material of test gears is SCr420H in the JIS and all gears are carburized. The electrohydraulic servo-controlled fatigue tester is used in the constant stress-amplitude fatigue test. The strength is expressed by the fillet stress level, which is calculated by FEM. The obtained strengths of forged and hobbed gear are 1613 MPa and 1490 MPa, respectively. The strength of forged gear is increased 8% in comparison with that of the hobbed gear. The surface hardness is higher and the surface roughness is smaller in the forged gear, however, the residual stress is approximately same. The effect of improvement of the roughness by forging on the strength is small in 1%, and the main reason of the improvement of fatigue strength is considered as the continuous fiber flow.
Design Optimization of a Laptop Computer Using Aggregate and Mixed Logit Demand Models With Consumer Survey Data
Authors: Shiau Ching-Shin , Tseng Ian H. , Heutchy Andrew W. , Michalek Jeremy
Published: May 2009

Laptop computers are designed in a variety of shapes and sizes in order to satisfy diverse consumer preferences. Each design is optimized to attract consumers with a particular set of preferences for design tradeoffs. Gaining a better understanding of these tradeoffs and preferences is beneficial to both laptop designers and to consumers. This paper introduces an engineering model for laptop computer design and a demand model derived from a main-effects choice-based conjoint survey. Several demand model specifications are compared, including linear-in-parameters and discrete part-worth specifications for aggregate multinomial logit and mixed logit models. An integrated optimization scheme combines the engineering model with each demand model form for profit maximization. The solutions of different optimal laptop designs and market share predictions resulting from the unique characteristics of each demand model specification are examined and compared.
A Game-Theoretic Approach to Finding Market Equilibria for Automotive Design Under Environmental Regulation
Authors: Shiau Ching-Shin , Michalek Jeremy
Published: May 2009

Recent research has extended prior efforts to integrate firm-level objectives into engineering design optimization models by further enlarging the scope to investigate the effects of regulation on the design decisions of profit-seeking firms in competition. In particular, one study examined the effects of environmental policy on vehicle design decisions by integrating quantitative models of engineering performance, market demand, production cost and regulatory penalties in a joint optimization framework using game theory to model the effects of competition on design and pricing. Model complexity and the solution methods used to solve for market equilibria in prior research have led to a limitation where the prior approach is too computationally intensive to allow extensive parametric studies on the effects of policy changes on design. To address this issue, we present an alternative game-theoretic approach utilizing necessary and sufficient conditions with Nash conditions to find market equilibria in an oligopoly of automakers, and we use this approach to examine the resulting optimal design responses under various regulation scenarios.
On the Differential Geometry of Flows in Nonlinear Dynamical Systems
Authors: Luo Albert C. J.
Published: May 2009

In this paper, in order to investigate the relation between two flows given in two dynamical systems, a flow for an investigated dynamical system is called the compared flow and a flow for a given dynamical system is called the reference flow. A surface on which the reference flow lies is termed the reference surface. For a small time interval, the change rate of the normal distance between the reference and compared flows on the normal direction of the reference surface is measured by a new function (i.e., G-function). Based on the surface of the reference flow, the kth -order G-functions for the non-contact and lth-order contact flows in two different dynamical systems are introduced. Through the new functions, the geometric relations between two flows in two dynamical systems imposed in the same phase space are investigated without contact between the reference and compared flows. The compared flow passing through, returning back from and paralleling to the surface of the reference flow is discussed first. The tangency and passability for a compared flow to the surface of a reference flow with the lth-order contact are presented. The dynamics for the compared flow with such a contact to the reference surface is briefly addressed. Finally, the brief discussion of applications is given. The contact and tangential singularity between two flows are different. The kth-order contact of the compared flow to the reference surface indicates that the compared flow to the reference surface is of the kth-order singularity. However, the compared flow with the kth-order singularity to the reference surface does not mean that the compared flow to the reference surface is of the kth-order contact.
Vibration of a Spinning Rotationally Periodic Rotor
Authors: Kim Hyunchul , Shen I. Y.
Published: May 2009

This paper studies the vibrations of a spinning, rotationally periodic (also known as cyclic symmetric) rotor through theoretical analysis and experimental studies. The theoretical analysis consists of two parts. The first part is Fourier analysis of mode shapes of a stationary rotor with periodicity N. A periodic mapping of the n-th mode shape shows that its k-th Fourier coefficient is generally zero, except when k ± n is an integer multiple of N. The second part is to apply the derived mode shapes through a unified algorithm developed by Shen and Kim [1] to predict primary and secondary resonances of spinning, rotationally periodic rotors. The experimental study focuses on vibration measurements of a spinning disk carrying 4 pairs of evenly spaced brackets mounted on a high-speed air-bearing spindle. Initially, experimentally measured waterfall plots do not agree well with those from theoretical predictions. Further numerical studies show that mistune of rotationally periodic rotors could substantially change their waterfall plots. After the mistune is modeled, experimental and theoretical results agree very well with a difference of only 0.8% in natural frequencies observed in the ground-based coordinates.
Product Family Concept Generation and Validation Through Predictive Decision Tree Data Mining and Multi-Level Optimization
Authors: Tucker Conrad S. , Kim Harrison M.
Published: May 2009

The formulation of a product family requires extensive knowledge about the product market space and also the technical limitations of a company’s engineering design and manufacturing processes. We present a methodology to significantly reduce the computational time required to achieve an optimal product portfolio by eliminating the need for an exhaustive search of all possible product concepts. This is achieved through a data mining decision tree technique that generates a set of product concepts that are subsequently validated in the engineering design level using multi-level optimization techniques. The final optimal product portfolio evaluates products based on the following three criteria: 1) The ability to satisfy customer’s price and performance expectations (based on predictive model) defined here as the feasibility criterion. 2) The feasible set of products/variants validated at the engineering level must generate positive profit that we define as the optimality criterion. 3) The optimal set of products/variants should be a manageable size as defined by the enterprise decisions makers and should therefore not exceed the product portfolio limit. The strength of our work is to reveal the tremendous savings in time and resources that exist when data mining predictive techniques are applied to the formulation of an optimal product portfolio. Using data mining tree generation techniques, a customer response data set of 40,000 individual product preferences is narrowed down to 46 product family concepts and then validated through the multilevel engineering design response of feasible architectures. A cell phone example is presented and an optimal product portfolio solution is achieved that maximizes company profit, while concurrently satisfying customer product performance expectations.