bluuebunny/crossref_metadata_2025 huggingface dataset:
The capillary fascicle in skeletal muscle: Structural and functional physiology of RBC distribution in capillary networks
Authors: Mendelson Asher A. , Milkovich Stephanie , Hunter Timothy , Vijay Raashi , Choi Yun‐Hee , Milkovich Shaun , Ho Edward , Goldman Daniel , Ellis Christopher G.
Published: February 2021

Key points

The capillary module, consisting of parallel capillaries from arteriole to venule, is classically considered as the building block of complex capillary networks. In skeletal muscle, this structure fails to address how blood flow is regulated along the entire length of the synchronously contracting muscle fibres.

Using intravital video microscopy of resting extensor digitorum longus muscle in rats, we demonstrated the capillary fascicle as a series of interconnected modules forming continuous columns that align naturally with the dimensions of the muscle fascicle.

We observed structural heterogeneity for module topology, and functional heterogeneity in space and time for capillary‐red blood cell (RBC) haemodynamics within a module and between modules.

We found that module RBC haemodynamics were independent of module resistance, providing direct evidence for microvascular flow regulation at the level of the capillary module.

The capillary fascicle is an updated paradigm for characterizing blood flow and RBC distribution in skeletal muscle capillary networks.

Capillary networks are the fundamental site of oxygen exchange in the microcirculation. The capillary module (CM), consisting of parallel capillaries from terminal arteriole (TA) to post‐capillary venule (PCV), is classically considered as the building block of complex capillary networks. In skeletal muscle, this structure fails to address how blood flow is regulated along the entire length of the synchronously contracting muscle fibres, requiring co‐ordination from numerous modules. It has previously been recognized that TAs and PCVs interact with multiple CMs, creating interconnected networks. Using label‐free intravital video microscopy of resting extensor digitorum longus muscle in rats, we found that these networks form continuous columns of linked CMs spanning thousands of microns, herein denoted as the capillary fascicle (CF); this structure aligns naturally with the dimensions of the muscle fascicle. We measured capillary‐red blood cell (RBC) haemodynamics and module topology (n = 9 networks, 327 modules, 1491 capillary segments). The average module had length 481 μm, width 157 μm and 9.51 parallel capillaries. We observed structural heterogeneity for CM topology, and functional heterogeneity in space and time for capillary‐RBC haemodynamics within a module and between modules. There was no correlation between capillary RBC velocity and lineal density. A passive inverse relationship between module length and haemodynamics was remarkably absent, providing direct evidence for microvascular flow regulation at the level of the CM. In summary, the CF is an updated paradigm for characterizing RBC distribution in skeletal muscle, and strengthens the theory of capillary networks as major contributors to the signal that regulates capillary perfusion.
Automatic Detection of Interactions in Feature Models
Authors: Bidarra Rafael , Dohmen Maurice , Bronsvoort Willem F.
Published: February 2021

Current feature-based modeling systems fail to adequately maintain feature semantics. This is partly due to inappropriate specification of validity conditions in feature classes, but mainly due to a lack of effective validity maintenance mechanisms throughout the modeling process. A critical aspect in this is feature interaction management. This paper presents a new approach to the detection of feature interactions, which uses semantic and interaction constraints in feature class specification. Validity maintenance is automatically performed after each modeling operation by checking these constraints, thus being able to detect a variety of interaction types. Such interactions are then analyzed, and their causes identified and reported to the user.
Requirements for Modeling Manufacturing Process: A New Perspective
Authors: Schlenoff Craig , Knutilla Amy , Ray Steven
Published: February 2021

A wide range of applications deal with the manipulation and expression of process-centered collections of activities. Each of these applications serves a specific audience and need, and focuses on particular aspects of a process. Nevertheless, much could be gained by sharing information among process-centered applications. One of the primary obstacles to such integration is the lack of a common representation the underlying concepts of process. The objective of the project described here is an investigation of the feasibility of a unifying specification of process that is applicable to multiple applications, yet powerful and robust enough to meet each set of requirements. This paper represents the results of the first phase of the project — that of researching the process representational requirements for design/manufacturing process life-cycle applications.
Performing DFM Analysis in Multiple Domains Using Interchangeable Manufacturable Entities
Authors: Krishnan Subramanian , Magrab Edward B.
Published: February 2021

An integrated design for manufacture system that performs manufacturability analysis simultaneously in two domains using interchangeable process specific entities is presented. This new approach is illustrated by an integrated system that creates and evaluates parts for manufacture by injection molding using a C-entity, and simultaneously creates and evaluates its mold for manufacture by milling using the fundamental manufacturing entity for milling. The entity for the part manufacturing process is chosen as the complement of the entity for the mold manufacturing process. This obviates the need for converting features from one manufacturing domain to another, and also permits a single uniform data structure to capture the shape characteristics of parts made in the two manufacturing domains. Since all the shapes are represented in the same way, the manufacturability evaluation of the part and the mold is reduced to a small set of algorithms based on an evaluation of the entity’s profile. It is demonstrated that by using process specific entities one can perform manufacturability evaluation of a part without either feature extraction or designing with features. The advantages of using the process specific entities approach for design and manufacturability evaluation over the feature recognition and the design by features approach are enumerated.
Least-Square Biarc Curve Fitting for CNC Machining
Authors: Kao Ju-Hsien , Loh Han Tong , Prinz Fritz B.
Published: February 2021

For CNC cutter path generation of nonlinear curves or surfaces, curve fitting using circular arc segments can be more efficient than linear segments. This paper presents a new algorithm for approximating large sets of points using a spline of biarcs, each of which consists of two circular arcs connected in tangent-continuous manner. The approach proposed in this paper differs from the previous work in that it does not require to pre-determine the number of arc segments, and yet all the family of biarcs between two points can be used, not only the ones which minimize the curvature difference or radii ratio. Combining the merits of least-square algorithms and binary search methods, this approach is capable of producing the minimum, or near minimum number of biarcs needed to approximate points within specified accuracy.
Active Catalog: Searching and Using Catalog Information in Internet-Based Design
Authors: Ling S. Ringo , Kim Jihie , Will Peter , Luo Ping
Published: February 2021

The exponential growth of the Internet and the increasing communication and computational power have created many opportunities for advancing engineering, manufacturing and business activities. Active Catalog brings a conceptually new idea to design and electronic commerce by providing new forms of catalog information about engineering parts and physical objects. Active Catalog is designed for finding and using information in building design applications in the context of heterogeneous, Internet-based distributed computing environments. The information provided by Active Catalog is active, dynamic, composable, multi-dimensional, share-able, semantically accessible, interoperable and executable in distributed environments.

Active Catalog allows engineers and designers to search for information about catalog parts syntactically and semantically, use that information to construct simulation programs rapidly, and test out their designs on the Internet before committing to actual fabrication of physical systems. It supports a new “Try Before You Buy” paradigm in the Internet-based design and electronic commerce.

This paper presents a number of research issues and our approach in building an Internet-based catalog information resource. The paper describes an initial prototype toward realizing the “Try Before You Buy” paradigm, in the context of the electromechanical design of pump and motor systems. The prototype contains a pump ontology and a search engine for finding semantically equivalent parts. The paper also describes a distributed simulation, which runs on various machines, and exchanges dynamic information using commercial data exchange mechanisms.
Special Panel Session for Feature Recognition
Authors: Han JungHyun , Regli William C. , Rosen David
Published: February 2021

Feature recognition is a discipline focusing on the design and implementation of algorithms for detecting manufacturing information such as holes, slots, etc. in a solid model. Automated feature recognition has been an active research area in solid modeling for many years, and is considered to be a critical component for CAD/CAM integration. This paper gives foundations for understanding the state of the art in feature recognition research. It also establishes the context for a special panel session at the 17th ASME International Computers in Engineering Conference. Four papers from different research groups participated in a benchmarking exercise on feature recognition; each wrote a paper on the results of executing their feature recognition systems on a collected set of parts. This panel session should serve as a catalyst for the feature recognition community to collaborate in establishing standard test parts and performance measures and in identifying and resolving research issues.
Structural Fire Calculations
Authors: Lilley David G.
Published: February 2021

Information and calculations are given for estimating fire growth in structural fires. Heat release rates from flames, fire growth, ignition of nearby items, and the possibility of flashover are all topics of concern. Empirical equations are given and calculations are exhibited to illustrated these aspects of structural fire behavior.
Evolution, Dispersion and Ignition of Flammable Fuel Release
Authors: Lilley David G.
Published: February 2021

The release into the atmosphere of toxic, flammable and explosive materials is extremely dangerous. If an ignition source is found, the resulting fire can often be devastating. Pertinent information and calculations are given related to the evolution (source release models), dispersion (contaminant dispersion models), and possible ignition of released material.
The Development of a Profile-Milling Program for Teaching Computer-Aided-Manufacturing and CNC Programming
Authors: Hotchkiss Anthony
Published: February 2021

At SUNY College at Buffalo, a new course, TEC302, CAD/CAM, computer-aided-design and computer-aided-manufacturing was added to the Industrial Technology (IT) undergraduate curriculum in the fall of 1994. At that time, the technology department had been using the AutoCAD system for design/drafting, and SmartCAM for demonstrating computer-aided-manufacturing.

SmartCAM is a sophisticated product that takes a great deal of training to use, does not work directly in AutoCAD, and with only four licenses, was not available to all the students.

For these reasons, the author developed a CAM program, VAL-CAM, that works inside AutoCAD, and has most of the aspects of a more sophisticated CAM program, yet is simpler to use, is available to all students, and automatically generates CNC (computer-numerical-control) code suitable for driving the departments’ vertical milling machining center.

This paper discusses the development of VAL-CAM, which is written in the AutoLISP language for compatibility with AutoCAD. The dialogue control language (DCL) of AutoCAD was also used for part of the user interface for VALCAM. The algorithms, flow diagrams, pseudo code and actual LISP code for some of the more interesting parts of the program are presented. VAL-CAM is under continuous development, and later sections of the program will be discussed in future papers.
Crash/Crush Analysis of Vehicle Structures Utilizing Thin-Walled Beam Elements
Authors: Tang Xiaodong , Cheng James C.
Published: February 2021

Using beam element in finite element analysis of automotive structures in the event of crash may significantly reduces the number of elements required to model the structures. It may significantly reduces the computing time for nonlinear integration. More significantly, it takes less time to establish, post-process and modify the models and is therefore, suitable for upfront engineering and concept analysis at early design stages. Considerable studies on beam elements (1–4) have been conducted and many commercial and academic finite element codes (5–7) incorporated it in their libraries. These beam elements are mostly based on the traditional theory that considers the deformation due to yielding and large displacement. However, the buckling phenomenon in the thin-walled components is not reflected in the formulation and therefore, the element are not suitable for thin-walled beams which are quite common in vehicle structures.

In this study, a thin-walled beam element is developed to incorporate both the deformation due to material yielding and the deformation due to the buckling of the thin wall plates. The buckling characteristics of the plates is approximately and equivalently converted into the behavior of crush hinge. Like the conventional plastic hinges, the crush hinges are formulated into the finite beam element. The element buckling effect is reflected into the structural response.

The beam element is coded into a computer program. The major formulations of beam element, numerical integration schemes of dynamic analysis and contact loading are illustrated in the follow sections. The computer program is used to analyze vehicle structures and the examples are shown in this paper. It should be pointed out that due to the limitations of beam element it is not possible to consider local design features such as small holes and notches. In those cases approximation must be adopted in finite element modeling.
Group Decision Making in Product Design and Manufacturing
Authors: Yoshimura Masataka , Kondo Hideyuki
Published: February 2021

Reconciling the different desires and requirements of individuals within decision making groups is becoming increasingly important, as corporate structures tend to embody flat relationships more than hierarchical ones, and as computer networks gain ever more utility. In this paper, a computer aided decision making support system is proposed, that such groups of decision makers can rely on, in order to arrive at the best possible cooperative decisions. First, weighting coefficients for the factors to be evaluated are determined by pair comparisons based on the AHP (Analytic Hierarchy Process) method. The preference structures of the decision makers for these factors are expressed by single-attribute satisfaction functions. Next, these satisfaction functions are classified into two groups having opposite tendencies (positive, and negative) so that when graphed, the intersection of the two curves can be defined as a solution point where the decision makers can compromise. Then, improvement procedures are conducted based on compromise processes, so that the satisfaction levels at the solution point becomes as high as possible. Finally, these decision making procedures are demonstrated by analyzing the decision making problems encountered when designing an industrial robot.
Shape Optimal Design of Elastic Planar Frames With Elastic and Skew-Sliding Supports
Authors: Oblak M. M. , Kegl M. , Dinevski D.
Published: February 2021

This paper describes an approach to shape optimal design of elastic, statically loaded, planar frames with kinematically non-linear response where special attention is focused on consideration of elastic and skew-sliding supports. A frame structure is treated as to be assembled from several design elements each of them being defined as a Bézier curve. The design variables may influence the position and the shape of each design element, the cross-sectional properties of beam elements, the elastic properties of the supports as well as the angles of inclination of sliding supports. Highly accurate, locking-free and initially curved beam elements are employed to ensure accurate and reliable results. The optimal design problem is defined in a general form and its solution, by employing gradient based methods of mathematical programming, is discussed briefly. The theory is illustrated with a numerical example.
Kinematic and Kinetic Derivatives in Multibody System Analysis
Authors: Serban Radu , Haug Edward J.
Published: February 2021

Methods and identities for computation of kinematic and kinetic derivatives required for a broad spectrum of multibody system analyses are presented. Analyses such as implicit numerical integration of the differential–algebraic equations of multibody dynamics, dynamic sensitivity analysis, and workspace analysis are shown to require computation of three derivatives of algebraic constraint functions and first derivatives of inertia and force expressions. Computationally efficient derivative calculation methods and associated identities are presented for Cartesian generalized coordinates, with Euler parameters for orientation. Results presented enable practical and efficient computation of all derivatives required in multibody mechanical system analysis.
Utilizing the Effort/Motion Approach in the Simulation of Interconnected Rigid Body Systems
Authors: Perreira N. Duke
Published: February 2021

The effort/motion approach has been developed for use in designing, simulating and controlling multibody systems. Some aspects of each of these topics are discussed here. In the effort/motion formulation two sets of equations based on the orthogonal projections of a dimensional gauge invariant form of Newton’s Second Law occur. The projections are onto the normal and tangent directions of a dimensional gauge invariant constraint surface. The paper shows how these equations are obtained for a particular linkage with redundant effort and motion actuation. Two alternative Runga-Kutta based approaches for numerical simulation of the effort/motion equations are developed and applied in simulating the motion and determining the effort generated in the example linkage under various conditions. Oscillation about equilibrium positions, solutions with constant motion and with constant effort are given as examples of the approach.
Inverse Kinematics for Planar Parallel Manipulators
Authors: Williams Robert L. , Shelley Brett H.
Published: February 2021

This paper presents algebraic inverse position and velocity kinematics solutions for a broad class of three degree-of-freedom planar in-parallel-actuated manipulators. Given an end-effector pose and rate, all active and passive joint values and rates are calculated independently for each serial chain connecting the ground link to the end-effector link. The solutions are independent of joint actuation. Seven serial chains consisting of revolute and prismatic joints are identified and their inverse solutions presented. To reduce computations, inverse Jacobian matrices for overall manipulators are derived to give only actuated joint rates. This matrix yields conditions for invalid actuation schemes. Simulation examples are given.
Designing for Maintainability in Preliminary Aircraft Engine Design
Authors: Nottingham Carrie R. , Ortega Roberto A. , Rangarajan Bharadwaj , Koch Patrick N. , Mistree Farrokh
Published: February 2021

With the high performance demands of turbine engines, particularly during aircraft take-off and landing, the necessity of scheduled and unscheduled maintenance makes designing these engines for maintainability extremely important. Maintenance issues, however, are normally not addressed in the preliminary stages of design. Thus, we are interested in determining top level engine design specifications which include maintainability issues. For this study we use the High Speed Civil Transport aircraft engine cycle as our example. We identify critical maintenance actions and levels for the HSCT and map these maintenance issues into the conceptual design phase. To facilitate a thorough concept exploration process for top level design specifications including maintainability issues, we implement the Robust Concept Exploration Method (RCEM). Our focus in this paper is to demonstrate a method of abstracting maintainability issues to the preliminary stages of design, rather than the results per se.
Curve Skinning Using Dual Kriging
Authors: Limaiem Anis , ElMaraghy Hoda A.
Published: February 2021

This paper presents a new method for curve skinning based on dual Kriging interpolation. Curves that have arbitrary parametric forms are used to generate the surfaces. The surface generated is invariant under affine transformations and translations if the generator curves are also invariant under these transformations and the surface is as smooth as the Kriging profile. A general Kriging profile is used for the interpolation. Derivatives data and linear constraints may be specified along the cross direction at each generator curve, hence, allowing the construction of blending surfaces with continuity specifications. Curve sweeping may also be treated using the same methodology. This method has potential applications in surface design and reverse engineering.
Robust Design for Dynamic Performance: Optical Pick-up Example
Authors: Seki Kenichi , Ishii Kosuke , Esterman Marcos
Published: February 2021

To achieve high quality and reliability in mechatronics products, thorough consideration of dynamic performance in structural design is essential. Typical examples include the design of optical pick-ups for disk related products, such as Compact Disc (CD) drives, and Magneto-optical Disc (MO) drives. Many researchers have developed design methodologies to optimize the nominal dynamic characteristics. Recently, robustness of dynamic performance has become an important issue in addition to optimizing nominal performance. Engineers seek to improve the quality of products by minimizing the effects of numerous variations that arise during the product’s manufacturing and life-cycle operation. This paper reports on the application of the robust design concept to the dynamic design of an optical pick-up actuator focusing on shape synthesis using computer models and design of experiments. By comparing this approach to analytical sensitivity solution, the authors provide a rationale for using the relatively simple statistical approach with orthogonal arrays.
Computationally Simple Xerographic Subsystem Models for System Model Synthesis Using MARS
Authors: Rai Sudhendu
Published: February 2021

This paper presents the application of the MARS (Multivariate Adaptive Regression Splines) (Friedman [1]) algorithm as an approach for developing computationally simple input-output models of subsystems. The algorithm will be used to construct models from experimental data as well as to develop simpler approximate models from computationally expensive finite element models over a range of design variables of interest. It will be demonstrated that these simplified models can then be used to construct more elaborate system models that consist of a large number of interacting subsystems. The system model can be used for performing a large number of what-if studies and studying the interactions between the subsystems. The examples presented in this paper will be from the xerographic design domain although this approach to modeling can be applied to other engineering domains as well. Specific advantages of this approach will be highlighted including its ability to handle moderately large data-sets in a semi-automated manner.
Deposition Strategies and Resulting Part Stiffnesses in Layered Manufacturing
Authors: Kulkarni Prashant , Dutta Debasish
Published: February 2021

In most Layered Manufacturing (LM) processes, the choice of deposition strategy plays an important role. In this paper, the effects of different deposition paths on a specific deposition based LM process are investigated. Some variations on the current deposition strategies are also proposed. The stiffness of parts manufactured by the different strategies is experimentally determined. It is then compared with an analytical model developed by using laminate analysis. A good conformance of the laminate model to the experimental results suggests that the laminate model can be used as a design aide to help the designer to tailor the deposition strategy to the stiffness requirements.
Development of an AutoCAD-Based Geometric Tolerancing System
Authors: Tsai Jhy-Cherng , Chang Jing-Sheng
Published: February 2021

Geometric tolerancing is an important factor affecting the functional performance and manufacturing cost of a product. Tolerancing specifications have to be assigned with care at design time to reduce the gap between design and manufacturing. This paper describes a system that simplifies tolerancing assignment and uses dimensioning and tolerancing data for related applications. The system consists of five modules for feature type classification, tolerance assignment, tolerance network construction, frame transformation, and tolerance analysis interface. It provides an interactive interface for tolerance assignment based on geometric features that a designer can select from decomposed isometric drawing. The system also recognizes the type of a feature so that only appropriate tolerancing specifications can be assigned. Geometric dimensioning and tolerancing data are used to construct a network for representing the tolerancing and mating relationship among features. The network is then converted for tolerance analysis via a tolerance analysis interface.
Thermal Issues in the Design of an SLS Rapid Prototyping Machine
Authors: Norrell Jeffery L. , Crawford Richard H. , Wood Kristin L.
Published: February 2021

In Selective Laser Sintering (SLS), one of several powder-based Rapid Prototyping (RP) methods, thermal transfer plays an important role in machine design. Thermal control of the processing area or “space” is crucial for accurate, repeatable part formation. In a typical SLS powder bed, significant thermal transfer occurs through mixed convection and conduction. In this paper, a polymeric powder bed subjected to in-bed convection is investigated with the goal of quantitatively determining transient thermal behavior. A numerical model describing heat transfer within a powder is presented. Convection and conduction are both numerically shown to play important roles in steady state temperature profiles. The design and construction of an experimental apparatus to measure the temperature profiles within a powder subjected to forced convection are also described. Full factorial experiments are used to calibrate and validate the numerical model, as well as to examine transient behavior. Using information gained from numerical and experimental work, suggestions are made for machine design to better control part precision and reproducibility. For example, it is shown that actively controlling the temperature of air convected through the powder bed gives fine, rapid control over the feed side cylinder thermal state.
New Matrix-Theory-Based Definitions for Manipulator Dexterity
Authors: Soper R. Randall , Canfield Stephen L. , Reinholtz Charles F. , Mook Dean T.
Published: February 2021

Historically, the evaluation of the “dexterity” of a given manipulator has been presented as a difficult qualitative and context-dependent task. The nature of this task has given rise to numerous definitions for quantitative properties associated with a manipulator, all referred to as dexterity. By divorcing the kernel of the idea of dexterity from the qualitative evaluation, a novel, unified, and simple definition for manipulator dexterity has been developed. The new definition of dexterity retains the spirit of all previous definitions. Simplicity is retained by recognizing that all velocity analyses and hence all measures of dexterity are governed by linear systems of algebraic equations. The derivations presented are general and may be universally applied to both redundant architectures and non-spanning substructures.
Using Symmetry to Reduce Planning Complexity: A Case Study in Sheet-Metal Production
Authors: Wang Cheng-Hua , Bourne David A.
Published: February 2021

In this paper, we present an approach to recognize symmetries of bent sheet-metal parts at different manufacturing stages. This approach is based on Waltzman’s (Waltzman, 1987) 2D symmetry detection algorithm. 3D symmetry is recognized by considering its 2D symmetry and the associated bending transformations. We show, by recognizing that the part is symmetrical, that the planning complexity for processes in sheet-metal production can be greatly reduced. This paper is motivated by the fact that a significant percentage of sheet-metal parts are symmetrical. We have studied over 200 industrial parts and over 40% of them are symmetrical. Examples from sheet-metal nesting (layout planning), bending, stacking, product decomposition and assembly planning are discussed.
Improving Manufacturing Precision Using the Karhunen-Loève Transform
Authors: Tumer Irem Y. , Wood Kristin L. , Busch-Vishniac Ilene J.
Published: February 2021

The status of fault patterns on part surfaces can provide valuable information about the condition of the manufacturing system. In this work, we aim to develop a reliable fault detection and diagnosis tool in order to assure the automated production of high-quality parts. Such a tool provides a means of integrating the manufacturing and design phases. Accurate detection of the part surface condition in manufacturing ensures the fault-free design of the manufacturing parameters and machine components.

This paper introduces a mathematical transform that has the potential to detect faults in manufacturing machines. Specifically, the paper focuses on the decomposition of complex signals to allow the detection of faults. The Karhunen-Loève transform is investigated by means of numerically-generated signals. Numerical signals are studied to decompose a variety of signals, including deterministic, stochastic, stationary, and nonstationary signals. Finally, the potential utility of the proposed technique is discussed in the context of a newly-maturing manufacturing process.
A Two-Level Product Model for Simulation-Based Design of Mechanical Systems
Authors: Chang Kuang-Hua , Choi Kyung K. , Wang Jeff J. Y. , Tsai Chung-Shin , Hardee Edwin
Published: February 2021

This paper presents a two-level product modeling method that supports Simulation-Based Design (SBD) of mechanical systems, primarily ground vehicles and heavy equipment, for preliminary and detailed design. A Computer-Aided Design (CAD) model combined with engineering parameters and mathematical equations that describe physical behavior of the mechanical system constitute its product model for SBD. For preliminary design, improvement of system performance, including dynamics and human factors, is the primary focus. A CAD model with reasonably accurate physical parameters, such as mass properties, is defined as the base definition of the product model. A parametric study can be conducted to search for design alternatives using dimension parameters created in the parameterized CAD model. Component designs are the primary focus in the detailed design stage. A detailed product model is evolved from that of the preliminary design, by refining geometric representation of mechanical components in CAD and expanding product assembly into parts and sub-assemblies for further engineering analysis. In the detailed design stage, a systematic design trade-off method is usually needed for design improvement. In both design stages, CAD and Computer-Aided Engineering (CAE) mappings that tie dimension parameters in the CAD model and physical parameters of simulation models facilitate the parametric study and design trade-off by quickly generating simulation models to simulate performance of the modified design. A High Mobility Multi-Purpose Wheeled Vehicle (HMMWV) is employed to illustrate and demonstrate the modeling method.
A Network Computing Language Environment for Design and Manufacturing
Authors: Cheng Harry H.
Published: February 2021

With the development of the World Wide Web (WWW), the computing paradigm has been shifted from the central processing in the 1970s, client/server based computing in 1980s, to today’s network computing. In the network computing, it is not computers on the network, but the network itself is the computer. This fundamental change of computing paradigm is opening up a whole new world of opportunities for design and manufacturing that have not existed before. We have developed a network computing language environment for design and manufacturing. The language environment is a superset of ANSI C. It has also been used for Web-based design of mechanisms, geometrical modeling, machine tool database search, CNC code verification, remote performance monitoring, control of real-time mechatronic systems. This language environment will be presented in comparison with ANSI C in this article. Major extensions to C will be highlighted. Of particular interest are the restricted and safe shells for Web-centric network computing. Details about integration of the language environment with Web server and browser will be described. This language environment and its Web-based application programs are available on the WWW at http://iel.ucdavis.edu.
Design and Virtual Prototyping of Rehabilitation Aids
Authors: Krovi Venkat , Kumar Vijay , Ananthasuresh G. K. , Vezien Jean-Marc
Published: February 2021

This paper presents a paradigm for virtual prototyping of a class of one-of-a-kind assistive devices that can be customized to the human user. This class consists of passive, articulated mechanical aids for manipulation that are physically coupled to the user. We address the mechanism synthesis, design and optimization and its evaluation in a virtual prototyping environment that consists of a CAD model of the product and a customized model of the human user. In addition, we develop the theory and methodology for designing planar serial chain mechanisms with revolute joints coupled by cable-pulley transmissions. As an illustrative example, we consider the design and prototyping of a customized feeding aid for quadriplegics.
An Information Modeling Framework to Support Design Databases and Repositories
Authors: Murdock J. W. , Szykman Simon , Sriram Ram D.
Published: February 2021

This paper introduces an information modeling framework to support representation of design artifacts for design databases and repositories. While most artifact representations consist primarily of geometric information, the object-oriented design modeling language developed through this work enables representation of not only form, but also function and behavior. This research has resulted in the implementation of a design artifact database as well as an information browser that provides the user interface to information contained therein. The implementation is demonstrated using the representation of a power drill as an example.
Managing Uncertainty in Preliminary Aeroshell Design Analysis
Authors: Scott Michael J. , Kaiser Rolf W. , Dilligan Matthew , Glaser Robert J. , Antonsson Erik K.
Published: February 2021

An analysis tool to aid in preliminary design of re-entry aeroshells for interplanetary exploration is presented. The computational tool addresses a common feature of design analysis, the need to make use of results from several analysis regimes and from several sources. This paper formalizes for computation what has historically been a matter of informal engineering judgment. The automation of design analysis allows for more extensive search of the design space, and thus supports a design process that is at once more thorough and more efficient.

The human designer uses experience and intuition to combine results from different analyses. Here, this combination is formalized by recognizing that each analysis tool is valid in particular regimes of the design problem; where regimes overlap, a combination based on participation factors (and utilizing the mathematics of fuzzy sets) is employed. An aggregated level of confidence for each solution point is also calculated.
Production Yield Estimation by the Metamodel Method With a Boundary-Focused Experiment Design
Authors: Tu Chinghsin , Barton Russell R.
Published: February 2021

The need for yield estimation strategies in the design stage is a priority recognized by industry. Yield estimates can be employed to assess the manufacturability of a design, and allow for modification to produce a robust design. Therefore, low yield of products can be avoided and costs for manufacturing can be reduced. This paper presents an accurate and time-efficient yield estimation approach for use with simulation models. We use a metamodel-based method, which is time-efficient compared to crude Monte Carlo yield estimation using the original simulation code. The approach employs a boundary-focused experiment design, which overcomes the inaccuracy of yield estimates that can occur when using a metamodel method. The results of two examples demonstrate the effectiveness of this new approach.
Integration Model to Support Archival of Design History in Databases
Authors: Qureshi Sohail M. , Shah Jami J. , Urban Susan D. , Harter Ed , Parazzoli Claudio , Bluhm Tom
Published: February 2021

A design history system is being developed to record the events and decisions that are involved in the evolution of an artifact. At present, design systems do not provide a formal mechanism of capturing such information as it is generated. This paper presents a framework that can be used for developing a system to archive and query electromechanical (EM) system design history, in a non-intrusive and structured way. A generic process model is presented that can describe and integrate specialized processes without requiring a priori definition of those processes. Finally, as an example, aerodynamic design process at Boeing Defense & Space group is modeled using the generic process model developed in this work. The work presented in this paper combines research from semantic modeling, product data modeling, process modeling, information technology, databases, and design theory to develop a computer based design history system (DHS).
Noun Phrases As Surrogates for Measuring Early Phases of the Mechanical Design Process
Authors: Mabogunje Ade , Leifer Larry J.
Published: February 2021

This paper reports on the use of design histories for the purpose of process evaluation. The technique involved exploring different representations of project documentation analogous to “X-ray photographs” of the human body. The study was conducted in the context of a graduate level design class that uses industry sponsored projects. It was found that the project grades in the class were strongly associated (gamma > 0.7) with the number of distinct noun phrases in the project documents while they were weakly associated with other variables like readability and number of words. These initial results show that noun phrases could serve as important surrogates for measuring the mechanical design process.
On the Use of Statistics in Design and the Implications for Deterministic Computer Experiments
Authors: Simpson Timothy W. , Peplinski Jesse , Koch Patrick N. , Allen Janet K.
Published: February 2021

Perhaps the most prevalent use of statistics in engineering design is through Taguchi’s parameter and robust design — using orthogonal arrays to compute signal-to-noise ratios in a process of design improvement. In our view, however, there is an equally exciting use of statistics in design that could become just as prevalent: it is the concept of metamodeling whereby statistical models are built to approximate detailed computer analysis codes. Although computers continue to get faster, analysis codes always seem to keep pace so that their computational time remains non-trivial. Through metamodeling, approximations of these codes are built that are orders of magnitude cheaper to run. These metamodels can then be linked to optimization routines for fast analysis, or they can serve as a bridge for integrating analysis codes across different domains.

In this paper we first review metamodeling techniques that encompass design of experiments, response surface methodology, Taguchi methods, neural networks, inductive learning, and kriging. We discuss their existing applications in engineering design and then address the dangers of applying traditional statistical techniques to approximate deterministic computer analysis codes. We conclude with recommendations for the appropriate use of metamodeling techniques in given situations and how common pitfalls can be avoided.
An Observational Study of Design Team Process: A Comparison of Student and Professional Engineers
Authors: Leong Alan , Smith Robert P.
Published: February 2021

Fifteen groups composed of engineering students and professionals were videotaped while performing a simulated design task. Using interaction analysis, it was found that professional teams were more likely to engage in management activities, outline an overall design philosophy, and not overlook detailed specifications. Professional teams also adhered tentatively to the early design artifacts; early design attempts were viewed as experiments for acquiring more information about the design space. Student teams were much more likely to engage in a generate and test pattern throughout their design process, making incremental improvements to their current artifact. Although the number of groups was small, these patterns were strong and the differences were statistically significant. It is suggested that these differences are useful for guiding how engineers are educated and for understanding whether students should be used as experimental subjects in engineering design research.
Experimental Performance of a Magnetorheological Fluid Damper
Authors: Kroushl Dan , Nesbit Amy , Lee Jin Kyoo , Marangoni Roy D. , Clark William W. , Schwartz Darrin , Phulé Pradeep P.
Published: February 2021

Magnetorheological (MR) and electrorheological (ER) fluids possess rheological or flow properties that can be controllably altered by the application of electric or magnetic fields, respectively. These fluids typically consist of dispersions of micrometer-sized dielectric or soft ferro (ferri) magnetic particles that become aligned in the presence of an external electric or electrical magnetic field, respectively. Such patterns in the material, which disappear when the field is removed, cause the material to resist mechanical deformation. This controllable property of the fluids allows them to be used in adaptive-passive actuators.

This paper presents the results of a preliminary experimental investigation into the performance of the MR fluids in a linear vibration damper. A squeeze-flow MR fluid damper is used to suppress vibrations of a simply supported beam. Four different MR fluids are compared.
Analytical Investigation on Elastodynamic Vibration Suppression of a Flexible Four-Bar Mechanism System Featuring a Smart Coupler Link and Multivariable Optimal Regulator
Authors: Sannah Muhammad , Smaili Ahmad
Published: February 2021

This paper presents an analytical investigation on active control of the elastodynamic response of a four-bar (4R) mechanism system using “smart” materials featuring piezoelectric sensor/actuator (S/A) pairs and multivariable optimal control. The 4R mechanism consists of a flexible coupler link, relatively flexible follower link, and a relatively rigid crank. Two thin plate-type piezoceramic S/A pairs are bonded to the flanks of the coupler link at high strain locations corresponding to the first and second vibration modes. Based on the optimal multivariable control theory, a controller which consists of a linear quadratic regulator (LQR) and a Luenberger observer as a state estimator is designed and implemented. As the mechanism changes configuration, its modal characteristics are recalculated, and the controller is redesigned.

The dynamic model used for the controller design includes the second and fourth vibration modes of the mechanism system. These modes are predominated by the first two bending modes of the mechanism’s coupler link. The results showed that while the proposed active control strategy is successful in reducing the amplitudes of vibrations about the quasistatic response, it has no effect on the quasistatic deflections due to steady state loading.
Optimization of Noise and Vibration of a Cylindrical Cam Mechanism Using Inertial Compensation Techniques
Authors: Ge Song Lin , Nerli Giovanni , Carfagni Monica
Published: February 2021

An innovative concept has been developed in which the dynamic behaviour of a cylindrical cam mechanism is modified using inertial compensation techniques. Elastic and magnetic compensation systems are incorporated in the experimental acoustic and acceleration analysis procedure. Both compensation systems have a remarkable effect on the reduction of the noise and vibration levels produced by the impact between the cam follower and the groove inversions. However, individually they both have different influences on the groove junctions. Generally they both have a considerable effect on the integral cam mechanism in terms of reducing emitted sound levels. The results also show that the difference in emitted sound levels before and after modification is approximately 3 dB. This conclusion means that the difference of the equivalent sound level is roughly equal to a reduction of about thirty percent below the original level with the compensation devices in position.
Actively Silencing a Cavity by Acoustic Impedance Changes
Authors: Lacour O. , Thenail D. , Galland M. A.
Published: February 2021

We attempt here the active control of enclosed sound fields via wall impedance changes. The impedance value which is the most efficient in silencing a cavity is the central point of this paper. Simulations and experiments show that the optimal impedance is not necessarily characterized by an large amount of absorbed power. Its silencing effect depends also on its ability to reduce source radiation. Experiments including fluid-structure interaction are also presented.