bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Differential Geometry Model of Assembly of Compliant Developable Sheet Components
Authors: Panton Stephen M. , Lissington Tony R. , Duncan John L. 
Published: January 2022

Abstract
In this paper we use the techniques of differential geometry to examine the geometric characteristics that might remain invariant throughout the shape changes of a compliant sheet component during assembly. We work from the premise that such shape changes take place by the easy deformation mode of bending, and that the membrane strains remain unchanged. To demonstrate the concepts, and to facilitate physical modelling, we restrict the compliant parts to ones which are developable. We examine two assembly conditions, those of a joint along a curve, and of fitting a compliant part to a physical or notional surface. We show that the first condition requires that the geodesic curvature of the curve remains unchanged, and the second condition requires that the Gaussian curvature distribution of the surface remains unchanged.
New Metrics for Evaluating Monte Carlo Tolerance Analysis of Assemblies
Authors: Cvetko Robert , Chase Kenneth W. , Magleby Spencer P. 
Published: January 2022

Abstract
Monte Carlo simulation may be used by engineering designers to predict the effects of manufacturing variations in mechanical assemblies. Validity of the predictions depends on the accuracy of the input variations, simulation sample size and the fit of a statistical distribution to the resultant assembly data. New metrics are presented for assessing the accuracy of variation analysis methods. Errors due to sample size are estimated for the mean, variance, skewness and kurtosis of the resultant distribution, and the predicted rejects.
Simple algebraic expressions are derived, which can be used to predict the error in the assembly variation parameters without having to repeat the simulation.
Simultaneous In-Process Roughness Control and Tool Wear Monitoring via a Distributed Open Architecture Controller
Authors: Hu Songhua , Shin Yung C. 
Published: January 2022

Abstract
This paper presents in-process roughness control and tool wear monitoring during a machining process. An in-process surface roughness monitoring system which uses ultrasonic sensing techniques was adopted in this research to provide roughness feedback. A roughness model which describes the relationship between surface finish, cutting parameters, and tool flank wear was developed and used as the basis of roughness control and tool wear monitoring. The roughness control and tool wear monitoring scheme was implemented using a distributed open architecture controller which provides an open environment for integration and development. The experimental results show that the tool flank wear can be monitored accurately by surface roughness and the control scheme can effectively compensate for the effect of tool wear and other disturbances to produce a constant surface finish throughout the life of the cutting tool.
Analysis of Stiffness Control and Vibration of Wire in Wiresaw Manufacturing Process
Authors: Wei Songbin , Kao Imin 
Published: January 2022

Abstract
In this paper, we study the stiffness and vibration behaviors of wire in wiresaw manufacturing process. The result of stiffness control and vibration analysis can be used to predict and reduce the kerf loss during the wiresaw manufacturing process. In modeling stiffness, the wire is treated as a wire stretched over a spherically bowed surface. The flexibility influence function (or the inverse of stiffness) of the wire under such geometry is studied. It is found that both the tension in the wire and geometry play important roles in the modeling of the stiffness of stretched wire in the wiresaw manufacturing process. The stiffness influence function is plotted and the results suggest control of stiffness through varying geometry and process parameters. Dynamically, the transverse vibration behavior of the axially moving wire is studied. The response under harmonic excitation is investigated with both closed-form and numerical method. The wire vibration is also simulated and plotted with three dimensional time history showing the vibration patterns of wire as a function of time.
Finite Element Analysis of Orthogonal Cutting With Blunt-Edge Tool
Authors: Chen Y. Richard , Ni Jun 
Published: January 2022

Abstract
A finite element model is developed for the simulation of orthogonal cutting of ductile material with blunt-edge tools. The model assumes the machining process as a quasi-static process, is capable of performing the coupled thermal-mechanical analysis, and adopts the continuous remeshing techniques. Based on this model, as well as the material property data of a low-carbon steel obtained from previous researches, orthogonal cutting process with blunt-edge tools is thoroughly analyzed. The analysis focuses on strain and stress distributions, deformation zones, chip flow characteristics, and cutting forces with the variation of process parameters such as uncut chip thickness and edge radius. Due to the computational load, thermal effect is not incorporated in the analysis. Some critical issues, such as chip stagnation point and recovery after ploughing, are investigated. It is found that uncut chip thickness and edge radius have some important influences on the strain and stress values, the shapes of deformation zones, and the cutting forces. The chip stagnation point has a consistent position on the cutting edge when the ratio of uncut chip thickness to edge radius is between 0.7 to 5. The recovery from ploughing is not significant. The intent of the study is to improve the basic understanding of the cutting process with blunt-edge tool for more precise modeling in the future.
Mixed-Integer Programming Model for Fixture Layout Optimization
Authors: Sayeed Quazi A. , De Meter Edward C. 
Published: January 2022

Abstract
Workpiece deformation during machining is a significant source of machined feature geometric error. This paper presents a linear, mixed integer programming model for determining the optimal locations of locator buttons, supports, and their opposing clamps for minimizing the affect of static workpiece deformation on machined feature geometric error. This model operates on discretized candidate regions as opposed to continuous candidate regions. In addition it utilizes a condensed FEA model of the workpiece in order to minimize model size and computation expense.
This model has two advantages over existing nonlinear programming (NLP) formulations. The first is its ability to solve problems in which fixture elements can be placed over multiple regions. The second is that a global optimal solution to this model can be obtained using commercially available software.
Effect of Workpiece Flatness and Surface Finish on the Holding Force of a Magnetic Chuck
Authors: Felix Alejandro , Melkote Shreyes N. 
Published: January 2022

Abstract
Magnetic chucks are commonly used for workholding in precision grinding and turning of ferromagnetic materials. The workholding force produced by the chuck is strongly influenced by the texture and form of the workpiece surface in contact with the chuck surface. This paper presents the results of an experimental investigation into the effects of workpiece surface flatness, finish, and texture on the normal and frictional workholding forces produced by a radial 4-pole electromagnetic chuck. Ring shaped case-hardened steel specimens are used in the experiments. The results show that the normal holding force decreases with increasing flatness deviation. The effect of surface roughness on the normal holding force is found to be small compared to the effect of flatness but significantly impacts the tangential holding force. The workpiece surface texture is also found to have an effect on the workholding forces.
Methodology for Detecting and Measuring Workpiece Distortion Caused by Fixture Clamping Forces
Authors: Carr Kirsten M. , Rodin Yelena M. , Smith Gregory H. 
Published: January 2022

Abstract
Fixture designers focus primarily on workpiece positioning and minimized movement. Ensuring minimized movement may lead to large clamping forces that distort the workpiece. Manufacturing engineers have difficulty determining if and how clamping forces distort a workpiece. A distortion detection method would provide valuable insights into identifying the clamping forces as a quality problem and contribute to a solution.
The proposed methodology determines the amount of distortion caused by fixturing by directly comparing the workpiece surface while in a fixtured state to the surface while in an unfixtured state. This methodology represents each fixturing state of the workpiece as a set of high resolution 3-dimensional point data. High Resolution Form Metrology compares these sets of data and produces color coded 3D images that detail the differences between various fixturing states. If clamping forces are causing workpiece deflection, these color coded images will indicate both the location and magnitude of the deflections.
Prediction of Optimal Clamping Force for Controlling an Intelligent Fixturing System
Authors: Wang Yunfeng , Fuh Jerry Y. H. , Wong Yoke San 
Published: January 2022

Abstract
This paper presents an Intelligent Fixturing System (IFS) which can adaptively adjust the clamping intensities to achieve minimum deformation of the workpiece according to the cutter position and the cutting forces during the entire machining process. The concept, architecture, control scheme, models and methodologies for the IFS are described. Using off-line simulations and on-line experiments, the performance of the IFS is evaluated and verified. Since adaptive clamping forces appropriate to the dynamic machining environment are provided, the proposed IFS offers higher quality of machined parts and more flexibility to disturbances. This system is suitable for application in a high-precision machining environment where a combined optimal machining and fixturing process is required.
Stress Analysis and Strength of Bonded Shrink Fitted Joint of Hollow Shafts Subjected to Torsional Load (The Effect of Bonded Shrink Fitted Position)
Authors: Yoneno Masahiro , Sawa Toshiyuki , Nakamura Takeshi 
Published: January 2022

Abstract
Recently, joints combining shrink fit with anaerobic adhesives have been introduced in order to increase the joint strength. This paper deals with stress analysis and strength estimation of bonded shrink fitted joints in which a ring is fitted at the end of the shaft subjected to torsional loads. The stress distributions at the interfaces of the joint are analyzed using the axisymmetric theory of elasticity. The effect of the outer diameter, height and stiffness of ring on the interface stress distributions are examined in the numerical calculations. It is seen that rupture of adhesive layer initiates from the edge of the interface close to the end of the shaft to which torsional load is applied. The numerical results show more conservative values than the experimental results. In addition, stress distributions in the present study are compared with those in which a ring is fitted at the middle of the shaft. It is found that the effect of shrink fitted position is negligible.
Stress Analysis and Strength Evaluation of Single-Lap Band Adhesive Joints Subjected to External Bending Moments
Authors: Liu Jiemin , Sawa Toshiyuki 
Published: January 2022

Abstract
The stresses in single-lap band adhesive joints of similar adherends subjected to external bending moments are analyzed as a three-body contact problem by using a two-dimensional theory of elasticity (plain strain state). In the analysis, the upper and lower adherends and the adhesive bonds which are bonded at two regions are replaced by finite strips, respectively. In the numerical calculations, the effects of the ratio of Young’s moduli of the adherends to that of the adhesives, the ratio of the adherend thickness to that of the adhesive bonds and the ratio of the bonding length to the total lap length on the stress distributions at the interfaces are examined. A method for estimating the joint strength is proposed using the interface stress and strain obtained by the analysis. Experiments to measure strains and rupture strength are carried out. A fairly good agreement is found between the estimated and the experimental results. For verification of the analysis, a finite element analysis (FEA) is also conducted. The results show that the strength of a single-lap band adhesive joint is almost the same as that of a single-lap adhesive joint in which the two adherends are completely bonded at the interfaces. Thus, the single-lap band adhesive joints are shown to be useful in the design of single-lap joints.
Hydroaccumulator Influence on SB LOCA Transients at PMK-2 Test Facility
Authors: Petelin S. , Parzer I. 
Published: January 2022

Abstract
In 1993 the International Atomic Energy Agency Standard Problem Exercise no.4 (IAEA-SPE-4), a small break LOCA scenario simulation with no high pressure injection system available, was performed on the PMK-2 integral test facility in Budapest. Later, in 1994, another SB LOCA experiment was performed. The analyses of the PMK-2 facility response, a model of WER-440 nuclear power plant, have been performed using the MOD3.2.1.2 version of the RELAP5 thermal-hydraulic computer code.
Mechanisms Governing Cyclic Deformation and Damage During Elevated Temperature Fatigue of High Strength Aluminum Alloy 7055
Authors: Srivatsan T. S. , Anand S. 
Published: January 2022

Abstract
The cyclic stress response, deformation and damage characteristics of aluminum alloy 7055 was studied at ambient and an elevated temperature. The specimens were cyclically deformed using tension-compression loading under total strain-amplitude control. The alloy showed evidence of softening to failure at the two test temperatures. The degree of cyclic softening increased with an increase in test temperature. The presence of deformable matrix strengthening precipitates and particles in the T7751 microstructure results in a local decrease in resistance to the motion of ’mobile dislocations, causing a progressive loss of strengthening contributions to hardening. At the elevated temperature, localized oxidation and embrittlement at the grain boundaries are promoted by the applied cyclic stress and play an important role in accelerating crack initiation and subsequent crack propagation. The damage response of the alloy is discussed in terms of competing influences of intrinsic microstructural effects, matrix deformation characteristics arising from a combination of mechanical and microstructural contributions, cyclic plastic strain amplitude and concomitant response stress, and test temperature.
A Comparison of the Fatigue Crack Growth Behavior of Single Crystal and Polycrystalline Inconel 718
Authors: Mercer C. , Soboyejo W. O. , Soboyejo A. B. O. 
Published: January 2022

Abstract
The fatigue behavior of a conventional, polycrystalline Inconel 718 alloy is compared to that of an experimental, single crystal alloy of equivalent nominal chemical composition. Differences between the fracture mechanisms exhibited by the two materials under cyclic loading were determined by scanning electron microscopy. The results of the fractographic analyses are presented on fracture mechanism maps that show the dependence of the fatigue fracture mechanisms on the maximum stress intensity factor, Kmax, and the stress intensity factor range, ΔK. The relative effects of ΔK and Kmax on the fatigue crack growth behavior of these two alloys are discussed within the context of a two-parameter crack growth law. The influence of grain boundaries on the fatigue crack growth resistance of materials such as Inconel 718 is also discussed in light of the results of this investigation.
Friction and Wear in Lubricated MEMS
Authors: Senft D. C. , Dugger M. T. , Smith B. K. 
Published: January 2022

Abstract
The friction coefficient of a plasma-deposited hydrophobic, teflon-like film is measured using a surface micromachined (SMM) friction test device. At a contact pressure of 84 MPa, the initial friction coefficient is 0.13, rising to 0.20 after 4 × 105 wear cycles. The wear of the surfaces is characterized qualitatively by SEM.
Holistic Approach for Problems in Heterogeneous Media
Authors: Fish Jacob 
Published: January 2022

Abstract
In analyzing composite structures it is common practice to carry out distinct levels of analysis corresponding to different length scales: (i) macroscale (structural level), (ii) mesoscale (laminate level), and (iii) microscale (the level of microconstituents). On the structural level structural components are treated discretely, while individual plies are not recognized, except in determining the stiffness of the shell. On the laminate level, individual plies are treated discretely, while microconstituents are treated collectively as a homogenized medium. The ply properties can be determined experimentally, or they can be predicted from micromechanics. For micromechanical analysis individual phases (matrix, fiber and their interphases) are treated discretely, while the atomic scale is not recognized. These steps comprise a sequence of interdependent analyses in the sense that the output from one level is used as input to the next level, where constitutive laws serve as bridging mechanisms between the scales. It is important to note that any level of analysis is currently performed totally independent of others provided that the required input data is available, perhaps from the experiment. There is no doubt, that this approach reflects a compromise aimed at bridging the length scales in excess of six orders of magnitude.
The Transverse Interface Strength of the Fiber-Matrix Interface in Polymer Matrix Composites
Authors: Criswell T. , Majumdar B. S. , Dutton R. E. , Matikas T. E. , Pagano N. J. 
Published: January 2022

Abstract
The transverse tensile strength of the fiber-matrix interface plays an important role in controlling a number of failure modes in polymer matrix composites (PMCs). These include the transverse failure of 90° plies, as well edge delamination in PMC laminates. On the other hand, while significant attention has been focused in the PMC literature on interface shear failure, such as under pull-out conditions, little attention has been focused on the interface tensile strength. In order to avoid edge effects, a cruciform geometry was selected for evaluating the tensile strength. SiC fibers with different types of coatings were evaluated inside an epoxy matrix, and the bond strength was estimated from the mechanical test data. Interface failure was confirmed using optical, dye penetrant, and an ultrasonic shear wave back reflection technique. Tests using straight sided specimens confirmed that singularities at specimen edges have significant influence on interface failure, and hence must be avoided for obtaining valid interface strength data.
An Atlas of Asymptotically Singular Stress Fields in Axisymmetric Fiber Push-Out Model
Authors: Pochiraju Kishore 
Published: January 2022

Abstract
Extracting fiber-matrix interface properties from single fiber push-out experimentation results requires careful micro-mechanical modeling. The axisymmetric concentric cylinder model is widely used to determine stress and damage state in the fiber, matrix, and at the interface. Several mechanics models developed for analyzing this model recognize the existence of asymptotically singular local regions for analyzing the stress fields in fiber push-out, but a comprehensive description of the nature of these stress fields and estimates for the regions of their influence is not available. Early work by Zak has shown that plane strain singularities which are separable in radial and angular directions dominate in the axisymmetric model at regions close to the point of singularity. Later efforts characterized the power of the radial singularity and angular variations of the singular stress fields in the model.
In this paper the qualitative and quantitative nature of the singular stress fields, their regions of dominance, and scaling of the stress intensity with applied load for several fiber-matrix interface conditions are described. The presented results are obtained using a local-global matching technique which uses combined asymptotic and finite element methods to determine the stress fields in the local regions.
The results are presented for both edge/corner singularities and for crack tip singularities in the model. The fiber radius and fiber volume fraction are considered as the geometric parameters. The material mismatch effects are considered using a wide spectrum of Dundurs mismatch parameters. Several interface conditions including perfectly bonded, partially cracked, debonding with frictional sliding of the crack tips and the oscillatory bi-material singularities are considered. Two different loading conditions, namely the thermal residual stresses and the push-in displacement loads are considered. The paper focuses on the local stress fields as determined by the first and second (when singular) terms of the asymptotic expansion and their scaling with applied loading.
The paper provides an atlas of the nature of the stress singularities (power of the stress singularity, mode mixity, the angular variation, and region of dominance) and the approximate stress intensity factors in the model for the two loading types for most practical fiber-matrix combinations, interface frictions and model geometric parameters.
Free-Edge Delamination in Layered Composites: A Historical Review of the Past 30 Years
Authors: Wang A. S. D. 
Published: January 2022

Abstract
In the inaugural issue of the Journal of Composite Materials in January, 1967, Editor S.W. Tsai elaborated in the Editorial the purpose and mission of his Journal. In it, interdisciplinary approaches to the basic problems of composites were emphasized. In particular, it called for the metallurgist and polymer chemist to face the problems of microscopic complex stresses and macroscopic material anisotropy, and for the elastician to go beyond the idealized elasticity problems, in order to include such real and practical effects as random fiber packing, imperfect interfacial bond, material inelasticity and fracture; only a close coupling of these disciplines could make the advancing composites technology fulfill it’s glowing promise.
Mechanics of Microvoid Formation During Resin Transfer Molding
Authors: Kang Moon Koo , Hahn H. Thomas 
Published: January 2022

Abstract
In resin transfer molding (RTM), the formation of air voids within fiber preform depends on the flow rate and surface tension of the resin during mold filling. The resin velocity in regions between fiber tows is mostly controlled by the induced pressure gradient whereas the resin flow within each fiber tow depends more on the capillary pressure. As these two flows compete in their advancement, the size and location of air voids vary from point to point. Capillary number, defined as the ratio of the viscous force to the capillary force, has been found through experiments to be the critical parameter controlling the type of microvoids.
The present paper proposes a model that can account for the dependence of the size and quantity of air voids on the capillary number. At low capillary numbers, the soaking flow within individual fiber tows dominates mold filling, and hence voids are more likely to form between fiber tows. At high capillary numbers, the situation is reversed so that the inter-fiber-tow flow outruns the intra-fiber-tow flow resulting in voids within fiber tows. At an optimum capillary number, the two flows are comparable, minimizing the possibility of void formation. The proposed model can quantify the effect of capillary number on void formation. The model has been validated through experiments.