bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Problem Solving Architecture for Virtual Prototyping in Metal to Polymer Composite Redesign
Authors: Zhou Kongyi , Lenz Timothy , Radcliffe Clark , Sticklen Jon 
Published: February 2021

Abstract
Conceptual design is an early but important stage of the design process that greatly affects the quality and cost of the final design. Intelligent tools that embody design rationale about function, structure, material, and manufacturing technology can help designers quickly generate and evaluate configuration ideas. This can help shorten the design cycle and reduce the risk of design failure in later stages. This paper presents a virtual prototyping system for redesigning metal structures out of polymer composites. The system provides a modeling tool to represent the original design based on a domain-specific ontology and a design transformation tool that generates, refines, and evaluates redesign concepts for composites. The discussion in this paper focuses on the system architecture that performs the design transformation problem solving. Important issues in the transformation strategies and control mechanisms are also addressed. An example of the redesign of a portion of an unmanned aerial vehicle is used to illustrate the redesign process throughout.
Generation of Design Data Through Numerical Modeling of a Post and Dome Feature
Authors: Nichols David A. , Luscher Anthony F. 
Published: February 2021

Abstract
This paper focuses on developing improved design equations to estimate the retention strength, insertion force, and insertion strain of a particular snap-fit, the post and dome feature. Finite element methods and multiple regression techniques were used in lieu of beam equations to develop the improved design equations. Sensitivity data is plotted for both the main effects and selected variable interactions. A study of detailed catch geometry was done in order to identify an optimal catch geometry. Typical design parameters were varied in order to develop design equations for users of this feature.
The post and dome feature was selected for analysis because it is a high performance snap-fit that is self-datuming and can take some shear loading in addition to retention. The post and dome provide a higher ratio of retention force to insertion force than traditional cantilever snap-fits, and retention is less dependent on friction.
Design of Optimally Stiff Structures Using Shape Density Function
Authors: Kumar Ashok V. , Wood Aaron 
Published: February 2021

Abstract
Optimization techniques for the design of the shape and topology of structures is presented where the geometry is represented using contours of a piece-wise bilinear shape density function. The relation between the material properties and the density function is studied to understand the influence of this relation on the optimal design obtained. Relations that would yield homogeneous and fully dense optimal designs are sought.
Turbine Disk Forging Process Optimization
Authors: He Beichang , Zhou Youdong , Gambheera Ramesh , Srivatsa Shesh K. 
Published: February 2021

Abstract
This paper addresses one of the important aspects of the turbine disk forging process — the design of die geometry to achieve near-net-shape forging. The problem is formulated as a parametric geometry and high-fidelity analysis based optimization problem. The forging weight is minimized within prescribed processing windows and forging rules including bounds on strain, temperature, strain rate, press capacity, dwell time, sonic coverage, fillet radius, draft angles, etc. A fully automated analysis and optimization system that works in a heterogeneous and networked computing environment is built on the top of three commercial software packages: DEFORM for simulating metal forming process, Unigraphics for defining and manipulating geometry, and iSIGHT for software integration and optimization. The system is applied to the optimization of turbine disks.
System-Level Functional Testing for Scaled Prototypes With Configurational Distortions
Authors: Cho Uichung , Wood Kristin L. , Crawford Richard H. 
Published: February 2021

Abstract
The means to obtain and manage design information is a critical factor that decides the performance of product development processes. Designers use both virtual and physical models to design high quality products. Relatively, virtual models are flexible and require less time and cost, and physical models more accurately reflect physical phenomena.
Correlation between physical models and products is difficult, except for situations in which the Buckingham Π theorem holds. We developed the empirical similarity method for situations not handled by the Π theorem. The empirical similarity method for products composed of a single material has been described previously. In this paper, we extend the empirical similarity method to predict behaviors of products composed of multiple materials. Through the extended method, one can perform system-level functional testing with prototypes.
Numerical and experimental examples are provided for illustration and validation purposes. The examples demonstrate the feasibility of the empirical similarity method to correlate systems with distinct configurations, and clarify expected industrial benefits.
Requirements for Testing Plastic Snap-Fit Features
Authors: Bodmann Douglas R. , Luscher Anthony F. 
Published: February 2021

Abstract
This paper discusses current efforts and evaluates future directions to construct and operate a physical-testing lab for the evaluation of snap-fit features. This testing is necessary for quantifying existing snap-fit features and verifying their numerical simulations. It will serve as an introduction into key issues in mechanical snap-fit feature testing. It reviews key decisions made to minimize error and maximize the ability to test a wide range of snap-fit topologies. A systematic approach to fixturing snap-fit topologies is proposed, dividing them according to basepart geometry and geometric description. Specific machine components are listed and selection criteria are expanded upon.
Sample feature information is presented. The post and dome and annular trap features results are specifically presented. Understanding their testing results aids understanding of issues in precision testing. Finally proposed future efforts for precision contacting and non-contacting alignment and other longer-term methodologies are mentioned.
Finite Element Modeling of a Moving Deformable Barrier for Fuel System Performance Simulations
Authors: Tyan Tau , Cheng James 
Published: February 2021

Abstract
An improved moving deformable barrier (MDB) model was developed for simulation of fuel system performance tests. This MDB model was designed to replace a bullet vehicle model for the vehicle-to-vehicle impact simulations where a bullet vehicle impacts a target vehicle at 50mph. This study included three crash modes, rear-inline, rear-50% offset, and side impact-centerline of fuel filler, required in the fuel system integrity test. The MDB model is composed of a barrier facial, same as the FMVSS (Federal Motor Vehicle Safety Standards) 214 [1] side impact barrier facial, and a movable cart on which the barrier facial is mounted. The main block and bumper block in the barrier facial are modeled by using solid elements while aluminum plates are represented by using shell elements. The movable cart is modeled by using beam elements with four air-bag tires. Two dynamic component tests were adopted to calibrate the barrier facial properties. To assure the model is applicable to all vehicle lines and different test modes, extensive validation was conducted. The full system validation contained a car, a mini-van, a van, and a pick-up truck. Three different test modes were all included in this study. Both accuracy and numerical stability of the model were examined carefully in each simulation. For accuracy, the deformation modes and responses of the MDB were compared to those of the tests. Time steps were monitored in each simulation to investigate the degradation of numerical stability. Through calibration and validation, the MDB model was found to be robust and numerically stable.
Feature-Based Slicing for Layered Manufacturing
Authors: Qian Xiaoping , Dutta Debasish 
Published: February 2021

Abstract
Layered manufacturing (LM) has become an indispensable manufacturing technology for product design and development. Competition pressure demands high quality LM part within an even shorter lead time. This requires an efficient fabrication strategy for LM. In contrast to prevalent LM methods whereby each layer is uniformly deposited with same layer thickness, we are exploring a different approach for LM. That is, fabrication strategies are localized to best meet the design specification of each individual feature in the part. Therefore, slicing, deposition path planning, etc., are done separately for each feature volume to get the best quality for that feature volume. Specifically, in this paper, we present a feature-based slicing method, which localizes the slicing for each individual feature volume. We propose the concept of feature interaction volume and describe how the part volume can be decomposed into refined feature volumes and feature interaction volumes. In refined feature volumes, the fabrication strategies are completely independent of the neighboring volumes. Some examples are presented to validate the feature-based slicing method.
Feature Decomposition for Hexahedral Meshing
Authors: Lu Yong , Gadh Rajit , Tautges Timothy J. 
Published: February 2021

Abstract
This paper presents a feature based volume decomposition approach for Hexahedral Mesh generation. In this approach, feature recognition techniques are introduced to determine decomposition features from a CAD model and the model is decomposed into sub-models, which become meshable or can be meshed by meshing algorithms in a computationally inexpensive manner. The feature recognition methods employed are convexity based and use topology and geometry information, which is generally available in BREP solid modelers. The procedure of feature decomposition is recursive: sub-models are further decomposed until either they are matched with appropriate meshing algorithms or no more decomposition features are detected. The code is designed and programmed for self-adaptation and error-tolerance to achieve high automation with complex geometry. The paper gives testing results for several complicated manufactured parts.
Evaluation and Comparison of Alternative Compliant Over-Running Clutch Designs
Authors: Roach Gregory M. , Howell Larry L. 
Published: February 2021

Abstract
Compliance criteria is used to evaluate the general class of over-running clutches to determine which type is best suited to benefit from compliance. The criteria used in the evaluation include the presence and amount of revolution of revolute joints, the possibility for part count reduction, the presence of springs, possible reduction in weight, and the method of clutch engagement. The ratchet and pawl type of over-running clutch was shown to be the most promising. Within this type of over-running clutch, different designs incorporating bending, tension, and compression loading of the pawls were explored to determine the best method for loading the pawls. The clutches were compared using a ratio of the maximum output torque to over-running torque. It was determined that the clutch incorporating rigid pawls loaded in compression produced the largest ratio of output torque to over-running torque. The maximum output torque for this clutch was measured at 65.6 N-m and the over-running torque was measured at 0.011 N-m yielding a ratio of 5964.
Geometric Features Applied to Composite Surfaces Using Spherical Reparametrization
Authors: Stewart Paul J. , Chen Yifan 
Published: February 2021

Abstract
The Direct Surface Manipulation (DSM) method allows creation and modification of user-specified features on an existing parametric surface. A global surface reparametrization scheme is presented that extends DSM to include features spanning multiple surfaces. This technique globally reparametrizes multiple surfaces onto a two-dimensional space, and the result is used as a global, uniform parametric space to connect the topologically-disconnected surfaces. Features defined on the common parametric space then span multiple surfaces. Spherical projection is presented as an effective projection method to use for the global reparametrization because of its ability to reduce shape distortions for features placed on surfaces with substantial curvature variation.
Dynamic Analysis of Five-Bar Mechanisms With Torsional Springs Using Lagrange’s Equation and Kinematic Coefficients
Authors: Nguyen Philip P. , Cipra Raymond J. 
Published: February 2021

Abstract
This research investigates the dynamic motion of planar closed loop two-degree-of-freedom five-bar mechanisms with torsional springs. An analysis technique is presented which incorporates a combination of the Lagrange’s equation and the method of kinematic coefficients in a manner similar to the power equation to achieve improved efficiency. Using the basic mechanism vector loop, the kinematic coefficients and the point path kinematic coefficients are solved symbolically. This information is then incorporated into Lagrange’s equation to produce a formulation that yields the equations of motion. The analysis technique is then tested using a simple example that validates the hybrid Lagrange formulation. An example of a generic five-bar mechanism with a torsional spring is given to demonstrate the use of the analysis technique. The example illustrates the motion of the linkage and the effect of altering certain mechanism parameters. The study reveals that the dynamic response of certain five-bar mechanisms with torsional springs can be significantly altered through minor design changes.
Fastening Strategies for Large Thin-Walled Enclosures
Authors: Jenkins David M. , Luscher Anthony F. , Suri Gaurav 
Published: February 2021

Abstract
Current attachment strategies for thin walled thermoformed panels use various concepts from screws, rivets, to snap-fits, etc. The most common of these strategies is to use standard metal fasteners such as pop rivets or screws. According to Boothroyd & Dewhurst analysis, separate fasteners do not add functionality to the product and therefore the overall assembly efficiency of the structure is low (Boothroyd and Dewhurst, 1989). Each fastener also adds several manufacturing and assembly steps. For each standard fastener a through hole must be drilled in the panels and the fastener must be inserted. There is also the possibility that the fasteners will not hold the panels tightly against each other resulting in joints with a poor physical appearance and a loss of structural stiffness.
This paper explores different innovative strategies to fasten thin walled thermoformed panels. The rod, ribbon and interlocking concepts use nesting strategies to aid attachment with the addition of a single separate part or allowing the walls themselves to form a joint. Nesting strategies are used to minimize the number of fasteners needed in a joint (Luscher et. al. 1996). A nesting strategy uses locating features to carry load in certain directions which reduces the load on the fasteners. Any reduction in load will lead to a reduction in the number of fasteners needed. The other concept discussed, separate plastic fastener concept, will change attachment from metal fasteners to independent plastic snap-fits. This is a simplified alteration resulting in minor changes to manufacturing and assembly processes.
Equations for attachment strategies with the use of certain concepts will be addressed. Also data from testing on snap-fits in use with a thin walled thermoformed structure will be reported.
A Product Variety Tradeoff Evaluation Method for a Family of Cordless Drill Transmissions
Authors: Conner Carolyn G. , De Kroon Joseph P. , Mistree Farrokh 
Published: February 2021

Abstract
In this paper we present the Product Variety Tradeoff Evaluation Method for assessment of alternative product platforms in product family design. The Product Variety Tradeoff Evaluation Method is an attention-directing tool for evaluating tradeoffs between commonality and individual product performance for product platform alternatives with differing levels of commonality. We apply the Product Variety Tradeoff Evaluation Method to a case study in transmission redesign for a family of cordless drills. The emphasis in this paper is placed on the method rather than on the results, per se.
Optimized STL File Generation From Scattered Data
Authors: Wang Y. Z. , Chen Y. H. 
Published: February 2021

Abstract
In this paper, a novel method is proposed for the prototyping of digitized data by means of rapid prototyping technologies without constructing a CAD model. Firstly, an optimized STL file (the de facto file format for rapid prototyping machines) is constructed directly from digitized part data. In order to reduce storage space and increase computational efficiency for subsequent processes such as slicing, significant data reduction can be achieved at users’ discretion by deleting data points in planar and near planar regions. Points around the ‘blank region’ left by deleted triangles are linked through re-triangulation to form triangular facets obeying STL file rules. To obtain optimized re-triangulation result, a genetic algorithm (GA) is developed and implemented. Finally, experiments on different amount of data reduction over a digitized sample are conducted with satisfactory results.
Minkowski Operators and Features of Voxel Models
Authors: Chandru V. , Manivannan M. , Manohar S. 
Published: February 2021

Abstract
Feature-based design has evolved as a fundamental paradigm for present-day CAD systems. Voxel-based modeling has many advantages over traditional representation schemes but lacks structural information which is lost in voxelization of the objects. In this paper, we propose to augment voxel models with features by a) storing the sequence of modeling operations along with voxel models and b) by defining feature operators. We have implemented these ideas in our prototype system Sirpi as regularised Minkowski operators using simple data structures and algorithms.
Methodology for Designing Low-Vibration Structures for Movable Mechanisms
Authors: Yoshida Shinobu , Kawabe Yoshiko 
Published: February 2021

Abstract
The methodology dealt with here is the way how to use numerical simulation methods corresponding to different design steps. The methods are a budget simulation method for mechanical specification design step, a structural vibration analysis method using a finite element method and an optimization method. The latter two methods are used for the module design and parts design steps. Case studies reviewing the works of authors show the effectiveness of the methodology.
A New Method for Determining the Effects of Structural Flexibility on the Dynamic Behavior of High Speed Mechanisms
Authors: Yuan L. , Rastegar J. 
Published: February 2021

Abstract
A new method for the analysis of the effects of structural flexibility on the dynamic behavior of mechanical systems is presented. The developed method is in most part based on “tracing” the “propagation” of the effects of the high frequency motion requirements on the dynamic response characteristics of machines with structural flexibilities, particularly those with closed-loop kinematic structures. The method considers the “filtering” action of structural elements with flexibility. Such filtering of higher frequency motions is shown to have a predictable effect on the steady state motion of such mechanical system. The main advantage of the developed method is that the effects of such flexibilities can be determined without the need to perform the usual dynamics modeling and computer simulations. The method is shown to be very simple and readily implementable. The method is applied to a four-bar linkage mechanism with a longitudinally flexible coupler link. The obtained results are shown to be highly accurate as compared to those obtained by computer simulation. The application of the method to systematic design of machines with structural flexibility for high speed and precision operation, optimal integration of smart (active) materials into the structure of such machines, and some related issues are discussed.
A Systematic Method for Optimal Integration of Smart Materials Into the Structure of High Speed Mechanisms
Authors: Yuan L. , Rastegar J. 
Published: February 2021

Abstract
A systematic method is presented for the integration of smart (active) materials based actuators into the structure of mechanical systems in general and mechanisms with closed-loop chains in particular for the purpose of modifying the output motion of the system. In the resent study, the method is applied to a four-bar linkage mechanism with a constant input velocity for the purpose of eliminating the high harmonic component of the output link motion. By eliminating the high harmonic component of the output motion of a mechanism, the potential vibrational excitation that the mechanism can impart on the overall system and its own structure is greatly reduced. The resulting system should therefore be capable of operating at higher speeds with increased precision. For mechanisms with rigid links, the primary source of high harmonic motions is the nonlinearity of the kinematics of the closed-loop chain. The usually less prominent high harmonic motions due to joint and/or structural flexibility may be eliminated in a similar manner and will be addressed in future publications.
A Pseudo-Rigid-Body Model for Functionally Binary Pinned-Pinned Segments Used in Compliant Mechanisms
Authors: Edwards Brian T. , Jensen Brian D. , Howell Larry L. 
Published: February 2021

Abstract
The pseudo-rigid-body model concept allows compliant mechanisms to be analyzed using well-known rigid-body kinematics. This paper presents a pseudo-rigid-body model for initially circular functionally binary pinned-pinned segments that undergo large, nonlinear deflections. The model approximates the functionally binary pinned-pinned segment as three rigid members joined by pin joints. Torsional springs placed at the joints model the segment’s stiffness. This model has been tested by fabricating several such segments from a variety of different materials. An example mechanism incorporating functionally binary pinned-pinned segments is also presented.
Regions of Feasible Point-to-Point Trajectories in the Cartesian Workspace of Fully-Parallel Manipulators
Authors: Chablat Damien , Wenger Philippe 
Published: February 2021

Abstract
The goal of this paper is to define the n-connected regions in the Cartesian workspace of fully-parallel manipulators, i.e. the maximal regions where it is possible to execute point-to-point motions. The manipulators considered in this study may have multiple direct and inverse kinematic solutions. The N-connected regions are characterized by projection, onto the Cartesian workspace, of the connected components of the reachable configuration space defined in the Cartesian product of the Cartesian space by the joint space. Generalized octree models are used for the construction of all spaces. This study is illustrated with a simple planar fully-parallel manipulator.