bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Accurate Explicit Direct Time Integration Method for Computational Structural Dynamics
Authors: Tchamwa Bertrand , Conway Ted , Wielgosz Christian 
Published: December 2021

Abstract
The purpose of this paper is to introduce a new simple explicit single step time integration method with controllable high-frequency dissipation. As opposed to the methods generally used in structural dynamics, with a consistency experimentally chosen of second order, the new method is only first-order-consistent but yields smaller numerical errors in low frequencies and is therefore very efficient for structural dynamic analysis.
The new method remains explicit for any structural dynamics problem, even when a non-diagonal damping matrix is used in linear structural dynamics problem or when the non-linear internal force vector is a function of velocities. Convergence and spectral properties of the new algorithm are discussed and compared to those of some well-known algorithms. Furthermore, the validity and efficiency of the new algorithm are shown in a non-linear dynamic example by comparison of phase portraits.
Quantification of Corrosion in 7075-T6 Aluminum Alloy
Authors: Obert B. , Ngo K. , Hashemi J. , Ekwaro-Osire S. , Sivam T. P. 
Published: December 2021

Abstract
In aging aircraft the synergetic interaction between corrosion and fatigue has been shown to impact the life expectancy of aluminum alloys. The objective of this study was to quantify the effects of corrosion, in terms of mass loss, on the static strength and fatigue life of 7075-T6-aluminum alloy. This was an experimental study conducted on samples with laboratory-controlled corrosion of varying mass loss levels at their mid-surface on one side. The specimens were covered with special masking material to allow corrosion only in the desired area. Both fatigue life and the ultimate tensile strength of the specimens were observed to drop significantly with small amounts of mass loss (less than 5%). After the initial decrease the UTS was observed to decrease linearly with additional mass-loss. The fatigue life of the specimens decreased significantly with additional mass loss. The topology of the pits, and the related subsurface damage hinted at existence of areas of high stress concentration resulting in the immediate reduction of UTS and fatigue life of the specimens.
Stress Concentration of Shape Memory Alloy Fiber Reinforced Composites in Elastic Axisymmetric Deformations
Authors: Tsai Hungyu , Fan Xinjian 
Published: December 2021

Abstract
In an effort to investigate the mechanical properties of shape memory alloy (SMA) fiber reinforced composites, the stress distribution due to the phase change in the fiber is examined. We study a simple model involving a single infinite fiber embedded in an infinite elastic matrix. A portion of the fiber is allowed to undergo uniform phase transformations along the axial direction while the matrix remains linearly elastic. Under perfect bonding condition, the deformation of the fiber forces the matrix to deform in the elastic regime in order to accommodate the transformation strain. To simplify the analysis, the elasticity of the fiber is ignored. The problem is formulated as axisymmetric deformations for the matrix with a piecewise linear boundary condition at the interface with the fiber as a result of the phase transformation in the fiber. The exact elasticity solution (in integral form) to this problem is found using Love’s stress function and Fourier transform. The normalized forms of the solution are presented. The asymptotic behaviors of the stress distributions near the phase boundary are analyzed in details. The characteristics of the singularities near the phase boundary are obtained for this model. Numerical evaluations are also performed to obtain the distributions of the displacements, the strains, and the stresses in the matrix. In particular, the shear load transfer profiles along the interface are obtained for various aspect ratios of the transformed region.
Elasto-Plastic Analysis of Thermal Stress Development During VAR of Ingots
Authors: Alam M. K. , Wong K. K. , Semiatin S. L. 
Published: December 2021

Abstract
The vacuum arc remelting (VAR) process has been developed to melt and cast high quality aerospace materials such as titanium alloys. VAR comprises the continuous remelting of a consumable electrode by means of a dc arc under vacuum or a low partial pressure of argon. The molten metal solidifies in a water-cooled copper crucible leading to high cooling rates that often results in large thermal stresses. The development of temperature gradients and the resulting thermal stresses during the VAR processes was investigated using an elasto-plastic material model with temperature dependent thermomechanical properties. Detailed solutions were obtained by using the commercial finite element code ABAQUS.
Promoting the Study of Science, Mathematics, Engineering and Technology in Urban School Districts via Video Programming
Authors: Mackie Calvin 
Published: December 2021

Abstract
This paper describes methods and theories used to alter the attitudes and motivation of the 83,000 students of the New Orleans Public School system. The project attempts to affect systemic change in the study of science, mathematics, engineering and technology via development of a motivational and informational video series from live presentations at target schools. The city of New Orleans and the New Orleans Public School system are demographically 75% and 85% African-American, respectively, and there is an overwhelming need to expose the students to role models beyond athletes and entertainers. The author has developed a comprehensive program to assist the New Orleans Public School system in developing motivation and fostering positive attitudes toward education, in general, and the study of science, math, engineering and technology, in particular.
The program’s goal and vision are to convince students that they can be whatever they choose with math, science, engineering and technology as possible alternatives, presenting career opportunities well into the next century by developing the whole individual into a motivated, critical thinking human being with the ability to make life-sustaining decisions. The videos are based on successful theories and presentations the author has developed and presented. Students at target schools are pre- and post-tested to determine the presentations’ effectiveness.
The videos are aired continuously on community and educational access channels across the city, reaching over 300,000 homes. Furthermore, a presently functional web site whereby students receive additional information and resources in the all areas of education including science, math and engineering complements the video series.
RoboCamp — Using Robotics to Teach Math, Science, and Engineering Principles
Authors: Vandergriff Katie U. , Cain Linda C. 
Published: December 2021

Abstract
RoboCamp provides an innovative experience in the area of robotics for educators. This fun, hands-on experience strengthens the teachers’ knowledge and skills in science, mathematics, engineering, and telecommunications and prepares them to effectively transfer the experience to students in the classroom.
RoboCamp is supported with a grant from the Tennessee State Department of Education and is a collaborative effort involving the Oak Ridge National Laboratory (ORNL), area school systems, industry supporting robotics, and the Universities of Tennessee and Memphis.
RoboCamp is held on-site at the ORNL and gives the teachers firsthand look at research in action. The teachers work side-by-side with scientists and engineers on robotics-related topics. These topics include the following:
• history and future of robotics;
• science, mathematics, and engineering as they relate to robotics;
• national standards and state and local curriculum frameworks;
• classroom implementation of robotics education utilizing national standards;
• current thinking on pedagogy and assessment; and
• fun, innovative ways to answer the age-old question, “But how do we use it in real life!?!”
RoboCamp participants tour a variety of sites that use robots. These tours include production plants, research facilities, and public schools involved in robotics education. Participants build several kinds of robots based on different operating principles, use computers and the Internet for robotics-related research, and work on a design problem using robotic solutions. Finally, participants work in teams to develop plans to transfer the experience to their schools.
Approximately twenty teachers are selected for participation in RoboCamp. Participants apply, and are selected, as members of a school team. A team is comprised of 3–5 members and may include teachers of the same grade or educators teaching different grades but within a school; teams are encouraged to include administrators and guidance counselors. Participants are paid a stipend and expenses. Teams are solicited statewide.
Design of a Multi-Finger Haptic Interface for Teleoperational Grasping
Authors: Springer Scott L. , Ferrier Nicola J. 
Published: December 2021

Abstract
In this paper the design of a multi-finger force-reflecting haptic interface device for teleoperational grasping is introduced. The haptic interface or “master” controller device is worn on the human operator’s hand and measured human finger positions are used to control the finger positions of a remote grasping manipulator or “slave” device. The slave may be a physical robotic grasping manipulator, or a computer generated representation of a human hand such as used in virtual reality applications. The forces measured by the robotic slave, or calculated for the virtual slave, are presented to the operator’s fingertips through the master providing a means for deeper human sensation of presence and better control of grasping tasks in the slave environments. Design parameters and performance measures for haptic interfaces for teleoperation are discussed. One key performance issue involving the high-speed display of forces during initial contact, especially when interacting with rigid surfaces, is addressed by the present design, reducing slave controller computation requirements and overcoming actuator response time constraints.
The design presented utilizes a planar four-bar linkage for each finger, to represent each finger bend motion as a single degree of freedom, and to provide a finger bend resistance force that is substantially perpendicular to the distal finger pad throughout the full 180 degrees of finger bend motion represented. The finger linkage design, in combination with a remote position measurement and force display assembly, provides a very light weight and low inertia system with a large workspace. The concept of a replicated finger is introduced which, in combination with a decoupled actuator and feed forward control, provides improved performance in transparent free motion, and rapid, stable touch sensation of initial contact with rigid surfaces. A distributed computation architecture with a PC based haptic interface controller and associated control algorithms are also discussed.
Failure Analysis and Design Improvement Considerations of Wood Screw Conveyors
Authors: Murphy Michael J. 
Published: December 2021

Abstract
Screw conveyors are a well know and well recognized means of moving material from one point to another. The wood products industry uses screw conveyors in the transportation of their raw materials throughout the mills. These screw conveyors are typically categorized by the common name of “wood screws”. Failures of wood screws are usually related to the imposed operating loads. Many wood screws are subjected to abnormally high loads that are sometimes not anticipated in the original design. Wood screws are also subjected to the effects of fatigue due to rotation. An unconventional new wood screw design was used at one location to address a condition of reoccurring failures and increase the reliability of the mill’s feeder system. This new design deviated from the popular method of fabricating the screw from one continuous piece of seamless pipe. Instead the new screw was fabricated by welding together pipe of two different wall thicknesses. The new screw design used one piece of thicker wall thickness pipe in the center one-third section and used two pieces of the original wall thickness pipe at each end. This design modification increased the section modulus and decreased the deflection of the screw at the center, but did not alter the existing drive and support arrangement of the screw. The welds between the different wall thickness sections of pipe were located at the quarter points which are away from the highly stressed areas of the center section of the screw.
Modeling and Optimization of Nozzle Design in Planar Flow Melt Spinning
Authors: Chen J. S.-J. , Tseng A. A. 
Published: December 2021

Abstract
Numerical and experimental studies were performed to analyze a planar flow melt spinning process (PFMS) with a focus on the optimal nozzle design. Three-dimensional computational fluid dynamics (CFD) modeling using FIDAP was carried out to analyze the flow distribution in various nozzle shapes including rectangular, trapezoidal, and hemispherical edges. A laser-based Particle Image Velocimetry (PIV) system was developed to measure the velocity field at the nozzle exit. The CFD modeling results were validated by the PIV measurements. It was found that a converging nozzle with diverging edges along with a 30°-injection angle provided the best design. The optimized nozzle was used to produce high quality ribbons as characterized by the surface roughness measurements and micrograph techniques.
Study of Metamodeling Techniques and Their Applications in Engineering Design
Authors: Wang Nanxin , Ge Ping 
Published: December 2021

Abstract
Physics based or mechanistic simulation models are frequently used in current engineering design to generate, evaluate and validate designs in order to shorten the design cycle time and reduce the cost. It often involves solving a set of none linear partial differential equations, which usually requires a lot of computing time to search for a solution. It can not satisfy the need to explore more design alternatives in the early design stage. Metamodeling is an active academic field and is attracting increased attention from the industry. Surrogate models built with the metamodeling techniques provide faster analysis alternatives to the mechanistic models. Using these surrogate models in the early design stage allows engineers to explore more design alternatives with less development time and therefore has the potential to enable better engineering decision to produce quality products for reduced cost. In this paper, we review the existing metamodeling techniques including design of experiments, response surface methodologies, machine learning, and kriging. The paper also documents the results of the performance evaluation of several different metamodeling tools using a vehicle greenhouse example.
Conceptual Process Planning: A Definition and Functional Decomposition
Authors: Feng Shaw C. , Zhang Y. 
Published: December 2021

Abstract
Conceptual process planning is an activity for designers to evaluate manufacturability and the manufacturing cost in the early design stage for mechanical parts production. Since major manufacturing costs of a product are committed in product specification and design, it is critical to be able to assess manufacturability and cost as early as possible in the design process. At the National Institute of Standards and Technology, the Design and Process Planning Integration (DPPI) project addresses the need for improving communication between conceptual design and conceptual process planning activities. Documenting the DPPI foundation, this paper provides a definition of conceptual process planning and describes its functions in an activity model. Also, this paper describes the conceptual process planning prototype system that has been implemented and integrated with a conceptual design system. The prototype system validates the definition, the activity model, and the integration between process planning and design in the early product development stage.
Graph-Based Setup Planning and Tolerance Decomposition for Computer-Aided Fixture Design
Authors: Zhang Y. , Hu W. , Rong Y. , Yen David W. 
Published: December 2021

Abstract
To bridge the gap between computer-aided process planning and computer-aided fixture design, an automated setup planning and tolerance decomposition method is developed in this research. Directed graph is extended to represent feature/ dimension/tolerance relationships (FTG) and datum/machining feature relationships (DMG). According to different production schemes and manufacturing resource capabilities, setup planning principles and algorithms are explored to automatically extract DMG from FTG. Under the true positioning frame (ANSI Y14.5), tolerance decomposition models are concluded to partition a tolerance into interoperable machining errors, such as locating error, tool alignment error, random process error. The setup plan with allowable locating tolerance specifications is the basis for fixture design. The proposed method is verified in a genuine manufacturing enterprise.
Determining Keyhole Stability for Plasma Arc Welding Process Control
Authors: Zhang Shaobin , Zhang YuMing 
Published: December 2021

Abstract
Stability of the keyhole plays a fundamental role in producing quality welds in keyhole plasma arc welding. Currently, keyhole size is assumed to be a measurement of its stability. To verify this idea, keyhole and weld pool were simultaneously imaged from the opposite side of the welding torch. Experimental results revealed that the width of the keyhole was not correlative with the stability of the keyhole: as long as the keyhole mode was maintained, the width remained constant despite the changes in the welding current and speed. However, it can be used to estimate the lower limit of the pool width for preventing keyhole collapse. Also, the upper limit of the pool width for preventing burn-through is approximately fixed for given applications. Hence, in this study, pool width, its upper limit, and keyhole width were used to determine the margins of the process from collapse and burn-through. To measure the state of the stability of the keyhole process, the stability distance and stability factor were proposed. Based on the imaging system used, the state of the stability can be monitored in real-time.
Virtual Rapid Prototyping Holography Basis
Authors: Wang Zhiyan , Guan Chengxiang 
Published: December 2021

Abstract
The so-called “virtual rapid prototyping” here is about a real 3D product modeling by holography. The basic work is to get large viewable angle and image depth hologram. A new method for recording rainbow hologram is proposed, multiple synthetic slits are created by displacing and multi-exposing an object, to expand hologram’s horizontal and vertical viewable angles, also the position of synthetic slit can be controlled to expand the image depth. There is no lens and real slit adopted for recording.
Hard Turning: Chip Formation Mechanisms and Metallurgical Aspects
Authors: Poulachon Gérard , Moisan Alphonse L. 
Published: December 2021

Abstract
A 100Cr6 (AISI E52100) steel in the hardness range of 180 to 750 HV10 was machined. Quick stop tests were carried out at various hardness values to observe the different chip formation mechanisms. A limit was found between the shearing and cracking chip formation. Experiments on the selected steel at 750 HV10 were carried out at various cutting speeds and feed rates. The “saw tooth chips” obtained were examined geometrically and metallurgically on longitudinal midsections. A relationship has been established between the chip geometry and the cutting conditions. A theoretical study of the chip shape was made, in particular its thickness. The friction stick slip velocities, and the segment apparition frequency were calculated. Each stage of the chip formation could be observed on each micrograph of Q.S.T, especially the crack initiation. A discussion on the apparition of the thin white layers is also proposed.
A Study of Cutting Forces for Milling Plain Carbon Steel Using Chamfered Main Cutting Edge Tools
Authors: Chang Chung-Shin 
Published: December 2021

Abstract
A new face milling model for tool geometries with a chamfered main cutting edge has been constructed. Theoretical values for cutting forces were calculated and compared to the experimental results with S45C medium carbon plate as the workpiece material. Force data from these tests were used to estimate the empirical constants of the mechanical model and to verify its prediction capabilities. A comparison of the predicted and measured forces shows good agreement Special tool holders were designed and manufactured to obtain various tool geometries, including chamfered main cutting edge, radial angle, axial angle and inclination angles. The tips were prepared to the required geometry using a tool grinder.
Cutting Fluid Aerosol Generation due to Spin-Off in Turning Operation: Analysis for Environmentally Conscious Machining
Authors: Chen Zhong , Wong Kinwah , Li Wei , Stephenson David A. , Liang Steven Y. 
Published: December 2021

Abstract
This paper presents an analytical model for the prediction of shop floor aerosol concentration and size distribution due to the spinoff of cutting fluid from a rotational workpiece in a turning operation. Based on atomization theory and principles of fluid motion, the model analyzes the generation of cutting fluid aerosol associated with the rotary disk and liquid sheet formations on the workpiece surface. In coupling with fluid flow rate analysis and Rosin and Rammler distribution model, the airborne particulate concentration and size distribution are expressed in terms of fluid properties, fluid application conditions, and machining process parameters. Experiments were performed with the use of light scattering particle measurement device to calibrate and verify the analytical models. Under various fluid flow rates and workpiece rotational speeds, experimental data have shown reasonable agreement with model predictions. The predictive models developed in this paper can be used as a basis for human exposure and health hazard analysis. It can also facilitate the control and optimization of the use of cutting fluids in achieving a balanced consideration of process productivity and environmental consciousness.
An Orthogonal Cutting Model Based on Finite Deformation Analysis: Part II — Constitutive Equations and Experimental Verification
Authors: Zheng Y. , Sutherland J. W. 
Published: December 2021

Abstract
In Part I of this paper, a model based on finite deformation analysis was developed to predict the forces in an orthogonal cutting operation. In the second part of the paper, the constitutive equations for O1 and L6 tool steels are developed using Hopkinson bar tests. A total of 90 statistically designed orthogonal cutting tests are conducted to investigate the cutting mechanics of O1 and L6 tool steels. Then the cutting model developed in Part I of this paper is applied to simulate all the 90 cutting tests using the measured material constitutive equations. All the measurable model outputs are calculated and compared with the corresponding cutting experiment results. The comparisons show that the cutting model based on finite deformation analysis can be successfully applied to predict the cutting forces, shear angle, and various relationships in machining (orthogonal cutting) tests.