bluuebunny/crossref_metadata_2025_split huggingface dataset:
Contract Manufacturing at Work: How to Avoid the Pitfalls of Outsourcing in a Global Economy
Authors: Shina Sammy G. 
Published: December 2021

Abstract
The increase in outsourcing and global contract manufacturing has led to significant impacts on the development of new products and their manufacturing operations conducted around the world. This paper outlines some of the outcomes of this trend in terms of changes to the product development process, manufacturing strategy, and human, financial, legal and business issues in global outsourcing. A strategy for new product realization and its manufacturing with the supply chain is then presented to select, manage and negotiate with suppliers in order to minimize adverse consequences of contract manufacturing.
Chip Geometry Based Modeling of Dynamic Tool Force/Motion Error Relationship in Diamond Turning
Authors: Ro Paul I. , Abler Jeffrey A. 
Published: December 2021

Abstract
This paper presents a comprehensive model of the dynamic tool force / motion error relationship for diamond turning. A key to a successful control of diamond turning process to achieve the theoretical finish lies in understanding the relationship that governs the generation of dynamic tool motion errors due to the variation in tool force. However, this relationship is neither well established nor simple, and is dependent upon material properties, various machining parameters, and the wear condition of the tool. In Part I, a model for this relationship is developed based upon the variations in the geometry of the tool and workpiece interaction resulting from their dynamic motion errors. The model is obtained as a first order variation from a static relationship, and consists of stiffness and damping terms. The total stiffness terms are characterized by variations in the chip geometry due to dynamic motion errors along the thrust direction. The thrust component of this model is then verified experimentally using the measurements of motion errors while simultaneously measuring the dynamic tool forces.
Assessment of Flow and Cure Monitoring Using Direct Current and Alternating Current Sensing in Vacuum Assisted Resin Transfer Molding
Authors: Jadhav Nitesh C. , Vaidya Uday K. , Hosur Mahesh V. , Gillespie John W. , Fink Bruce K. 
Published: December 2021

Abstract
Vacuum Assisted Resin Transfer Molding (VARTM) is an emerging manufacturing technique that holds promise as an affordable alternative to traditional autoclave molding and automated fiber placement for producing large scale structural parts. In VARTM, the fibrous preform is laid on a single sided tool, which is then bagged along with the infusion and vacuum lines. The resin is then infused through the preform, which causes simultaneous wetting in its in-plane and transverse directions. An effective sensing technique is essential so that comprehensive information pertaining to the wetting of the preform, arrival of resin at various locations, cure gradients associated with thickness and presence of dry spots may be monitored. In the current work, direct current and alternating current sensing/monitoring techniques were adopted for developing a systematic understanding of resin position and cure on plain weave S2-Glass preforms with Dow Derakane vinyl ester VE 411-350, Shell EPON RSL 2704/2705 and Si-AN epoxy as the matrix systems. The SMARTweave DC sensing system was utilized to conduct parametric studies a) to compare the flow and cure of resin through the stitched and non-stitched preforms, b) influence of sensor positioning, i.e., top, middle and bottom layers, c) influence of positioning of the process accessories, i.e., resin infusion point and vacuum point on the composite panel. The SMARTweave system was found to be sensitive to all the parametric variations introduced in the study. Furthermore, the results obtained from the SMARTweave system were compared to the cure monitored from embedded IDEX dielectric sensors. The results indicate that SMARTweave sensing was a viable alternative to obtaining resin position and cure, and more superior in terms of obtaining global information in contrast to the localized dielectric sensing approach.
Adaptive Influence Coefficient Control of Single-Plane Active Balancing Systems for Rotating Machinery
Authors: Dyer Stephen W. , Ni Jun 
Published: December 2021

Abstract
Rotating unbalance is a costly source of harmful vibration affecting a wide variety of applications such as high-speed machine tools and turbomachinery. Active balancing technology allows adjustment of a machine’s balance state while conditions change as the machine continues to operate. An adaptive control law for single-plane active balancing is presented here for control of steady-state rotation-synchronous vibration. The adaptive control method, based on the well known “influence coefficient” approach, requires no a priori modeling or estimation of plant dynamics. A control “gain” parameter is introduced and shown to enhance stability robustness of the non-adaptive portion of the control law. A recursive on-line system identification method is presented that uses exponential weighted averaging to mitigate the effects of measurement noise and system nonlinearities. Experimental results establish the efficacy of the adaptive control system even in the face of certain nonlinear and time-varying rotordynamic systems.
Study on Acoustic Emission During High-Speed Grinding and Ultraprecision Grinding of Advanced Ceramics
Authors: Gowri S. , Ngoi Bryan K. A. , Ramesh K. 
Published: December 2021

Abstract
The process of grinding produces characteristic acoustic emissions (AE) and the signals of AE could be used as ‘condition monitoring’ tool to understand the phenomenon involved in material removal. It has been observed that high-speed grinding of the ceramics improved machining productivity without deteriorating the surface quality of the ceramics, which is not common in the case of metals. Residual stress analysis on the machined ceramics indicated that built-in residual stress might have reduced the crack-formation. Critical grinding conditions limiting the formation of cracks on the ceramics were identified. The trend in AErms signals could be correlated to the grinding force and the grinding conditions. In case of ultraprecision machining, the ductile regime grinding of the ceramics was found out in terms of feed and depth of grinding with grinding velocity. Analysis with the SEM of machined ceramic surfaces and the AErms could reveal the occurrence of ductile regime grinding and also the transition of ductile to conventional brittle mode of material removal during grinding.
Development of the TIARA Hexapod: A Machine Tool Based on Parallel Kinematic Structures
Authors: Centea Dan N. , Lacheray Herve , Audren Frederic , Teltz Richard , Elbestawi Mohamed A. 
Published: December 2021

Abstract
The paper focuses on the TIARA Hexapod — a parallel kinematic machine tool that is being developed at McMaster University. The design uses fixed length struts, and an inclined layout for the motion axes that results in the mechanism resembling a ‘tiara’. In addition to the novelty of the design, these characteristics have several advantages from both a performance and economic perspective. The paper presents an overview of the development program for this machine tool, discussing issues related to design, modelling, inverse and forward kinematics, workspace, and dynamics analysis. Later sections of the paper detail the kinematic and dynamic models developed for the TIARA machine tool, and demonstrate their use for workspace analysis and the specification of actuator requirements.
Closed-Loop Shape Control of the Stretch Forming Process Over a Reconfigurable Tool: Precision Airframe Skin Fabrication
Authors: Valjavec Marko , Hardt David E. 
Published: December 2021

Abstract
The accuracy of stretch formed sheet metal parts in the aerospace industry depends heavily on tool designer and machine operator expertise. In addition, fixed-configuration facilities and rigid tools result in long lead times, high manufacturing costs and insufficient product quality. In response to this, a methodology combining an adaptive closed-loop shape control algorithm and a reconfigurable forming tool has been developed and implemented for stretch forming. This method is based on empirical estimation of the process characteristics using a “Deformation Transfer Function” and is capable of rapidly generating a tool shape that produces the desired final part shape, even when significant process uncertainties exist. The same control system is also used to compensate for shape distortions caused by the downstream manufacturing processes of chemical milling and trimming. Experiments involving various compound curvature skins are presented that validate the effectiveness of this methodology in reducing the shape errors below the forming system error threshold in just one or two closed-loop forming trials regardless of skin shape.
Flexible Forming of Sheet Metal Using Plasma Arc
Authors: Chen YiWei , Li PengJiu , Male Alan T. , Zhang YuMing 
Published: December 2021

Abstract
Conventional precision forming of sheet metal requires the use of mechanical tools. However, during product development, different tools may be required to form various shapes, thus requiring significant tool cost and lead time. If a rapid prototyping process were available such that the required shapes can be formed without the need for hard tools, the potential reduction in product development cost and lead time could be quite significant. Moreover, such a process could be used for very short run production where it would be uneconomical to amortize tooling cost over a small number of manufactured pieces. To explore the potential for flexible forming without tools, various researchers have used laser beams as a heat source to form sheet metals, with a significant measure of success. To investigate the use of a more economical and potentially safer heat source, the authors recently established an experimental system to investigate the feasibility of forming sheet metals using a non-transferred arc plasma as the energy beam and CO2 as the cooling jet. Several samples have been formed using the developed experimental system. Experiments have shown that the forming direction, either toward or away from the plasma arc beam, can be completely controlled to allow the formation of complex shapes. It is believed that this provides the basis for a new rapid prototyping process for the forming of sheet metal components.
Dynamic Modeling of an Indexing Valve Plate Pump
Authors: Cho J. , Zhang X. , Nair S. S. , Manring N. D. 
Published: December 2021

Abstract
The swash-plate in a variable displacement pump experiences very large forces and moments that try to dislocate its position and therefore a large device is required for adequate control. In this paper, the dynamics of an alternative pump design using an indexing valve plate to position the swash-plate are reported. The indexing valve plate design is aimed at controlling the pressure transition for a piston, which is moving from a high-pressure port to a low-pressure port and back. In this paper, the governing equations for the pump are derived and the detailed open-loop, which is necessary for understanding the overall dynamic characteristics of the pump, is reported. Also, linear and nonlinear modeling approaches for the system are compared.
Thermal Considerations in Fluid Power Systems Modeling
Authors: Fernandez Raul , Woods Robert L. 
Published: December 2021

Abstract
A systematic derivation of fluid capacitance for use in compressible and incompressible fluid power modeling is presented. Equations are stated explicitly for the control volume pressure and temperature states, which include a simple but realistic estimation of heat transfer effects based on a first-order approximation to the chamber wall thermal dynamics. Simulations representative of industrial hydraulic and pneumatic applications are presented, showing the expected fluid pressure and temperature responses for the control volume with various modeling assumptions, and ultimately justifying the use of simplified isothermal relations for hydraulics in general and for many low-pressure servopneumatic applications.
Pneumatically Operated Wheelchair for Step Drive
Authors: Shiraishi Masatake , Sumiya Hideyasu , Aoshima Shinichi 
Published: December 2021

Abstract
A new wheelchair capable of 10 cm-step drive has been developed. It uses pneumatic pumps installed on the rear wheels of the wheelchair. The pneumatic pumps generate pressurized air, which is sent to the reservoir, in proportion to the rear wheel rotation: travel of about 12 m is needed to reach full pressure. The required air is introduced from the reservoir into two driving cylinders, fixed to the front support frames, that lift the front wheels. The lifting operation is performed by handling the braking levers. Our experimental design system shows the feasibility of using pneumatic pumps for this operation.
Nonlinear Feedforward-Plus-PID Control for Electrohydraulic Steering Systems
Authors: Qiu Hongchu , Zhang Qin , Reid John F. , Wu Duqiang 
Published: December 2021

Abstract
This paper presents the development of a nonlinear feedforward-plus-Proportional-Integral-Derivative (FPID) controller for electrohydraulic (E/H) steering on wheel-type tractors. An E/H steering system is a typical nonlinear system with deadband, saturation, asymmetric flow gain, time delay, and other nonlinear behaviors. Conventional PID controllers are incapable of achieving accurate steering control effectively on such nonlinear systems. In this research, an FPID controller was developed for effective and accurate steering control. The feedforward loop in this controller was designed to compensate for the deadband of the E/H system. The PID loop was designed to compensate the tracking error in steering control. A coordinated nonlinear gain function was designed to change the PID loop gain based on the level of the tracking error. This FPID controller has significantly improved the steering accuracy comparing with that from a PID controller. Test results showed that the maximum tracking error in steering angle was less than 0.5° corresponding to a sinusoid steering command of ±5° at the command frequency of 0.1 Hz. The maximum overshoot was less than 12% and the rise time was less than 0.25 s corresponding to a steering command of 5° step input. This FPID controller achieved effective and accurate steering control on agricultural tractor E/H steering systems.
Robust Tolerance Design Considering Process Capability and Quality Loss
Authors: Feng Chang-Xue (Jack) , Balusu Ravi 
Published: December 2021

Abstract
Tolerance design bridges design and manufacturing. Concurrent design of tolerances and manufacturing processes may ensure the manufacturability, reduce the manufacturing and other related costs, decrease the number of fraction nonconforming (or defective rate), and shorten the production lead time. Since process capability indices relate tolerance specifications to manufacturing process capabilities, it is quite natural to apply them to concurrent design of tolerances and processes. As process shifts often exist in a manufacturing process, using Cp does not yield a good estimation of fraction nonconforming. Index Cpk does not precisely measure process shift either, but Cpm does. Therefore, this research compares the applications of Cp, Cpk and Cpm based on a numerical example of non-linear mechanical tolerance synthesis. In addition, the Taguchi quality loss function is used together with the manufacturing cost as the objective function.
An Optimized Production Technology Approach to Design for Throughput
Authors: Billatos Samir B. , Wolffarth Gregg 
Published: December 2021

Abstract
Many manufacturing organizations are losing their competitive position due to a large number of reasons discussed in this paper. To regain a competitive position, organizations must clearly understand their goals. The Goal for a manufacturing organization should be making money now and in the future [1,2]. Producing products, high utilization, keeping people busy, high quality, good customer service, etc., are means to the Goal but not ‘The Goal’ itself. To achieve an organization’s goal, management must turn to OPT. OPT (Optimized Production Technology) is the original and most advanced constraint based advanced planning and scheduling system [3,4]. It is the practical implementation of the Theory of Constraints in the modeling, planning and scheduling of activity based business. OPT has proven its applicability in job shop, repetitive manufacturing and process industries all over the world. Therefore, shop floor issues, such as bottlenecks, setups, lot sizes, priorities, random fluctuations and performance measurements, are treated in great depth. The OPT philosophy incorporates nine rules which, when followed, can help move the organization towards the goal of making money. Underlying each of the rules is the understanding that effective management of an organization takes a global perspective of all resources and their interrelationship to achieve the goal. These rules coupled with a set of measurements: Throughput, Inventory and Operating Expenses, would lead any manufacturing organization to fulfilling the goal. Since few literatures have covered the general application of these measures, this paper will focus only on Throughput. The paper will discuss the step-by-step implementation procedures that would help industry in designing their systems for throughput.
Competitive Conceptual Design of Engineering Systems
Authors: Bzymek Zbigniew M. 
Published: December 2021

Abstract
This paper discusses design resulting from a unique design competition as an indicator of the verification of scientific design principles as given by Shu Nam 1990. A single enactment of the design problem is used as a case study to illustrate different points of this paper. The focus of the paper is on the creative aspect of idea generation and the checking of subsystems as well as the complete system enactment for function and performance. In an annual design competition the same problem was issued to a number of design teams. The number of teams varied from nine to eighteen in different years and two to three designers were in a team. The design was performed by seniors in mechanical engineering. To generate concepts, Osborn’s method of brain storming was applied. The brain storming was done in the groups of two to three designers. It was applied to the entire system and subsequently to subsystems. After the abstract design was accomplished, prototypes were built and tested. A competition was held in which each design group prototype earned a figure of merit score based on its performance in a performance run. The figure of merit formula used to dtetermine the winner of the competition and race course for performance run were given to the designers at the time they were given the design problem statement. The results were verified by an expert evaluation with Mechanical Engineering faculty members serving as experts. Every prototype was competing with others in the same exact conditions. The results of the design competition provide a unique set of data which may be considered an experiment in design technique. Some concluding remarks concerning design methodology are stated.
Robust Design: Tolerance Design Method
Authors: Yang Hanxiang , Chen Pah I. 
Published: December 2021

Abstract
There are three phases involved in Robust Design — conceptual design, parameter design, and tolerance design. Parameter design aims to specify the variations of the design parameters in order to meet the design requirement, and the tolerance design further specifies the optimized parameters in order to reduce the performance variation near the design target. A robust design requires that tolerance design to be preceded by parameter design.
In this paper, our effort will be focused on presenting an iterative method to perform the tolerance design phase. Two hypothetical examples (whose parameter designs have been completed) will be used to illustrate the tolerance design methodology. The first example involves the design of a pneumatic cylinder whose piston movement can be expressed by a theoretical equation containing five parameters. With the equation, it becomes a simple task for determining the tolerances of the optimized parameters to constrain the design target. The second example involves the production of a agrochemical by mixing two chemicals to achieve a specific yield. A set of test data is available but the equation relating the parameters is not. In this case, we shall adopt the linear regression technique to obtain an experimental equation to represent the test data. Based on this equation, we can proceed to determine the tolerances of different parameters in order to achieve a specific variation of the yield.
The step-by-step procedure outlined in the hypothetical examples demonstrates that this iterative method is a simple and effective way to conduct the tolerance design.
Optimal Shapes of Fully Embedded Channels for Conjugate Cooling
Authors: Fisher T. S. , Torrance K. E. 
Published: December 2021

Abstract
Optimal shapes and geometries are determined for systems involving liquid and gas coolants. The shape of the channel boundary, channel width, and wall thickness are varied to minimize overall thermal resistance under flow constraints involving pressure drop and pump work. The effect of boundary curvature is studied systematically by employing a parameterized boundary shape that spans from rounded rectangles to ellipses to rounded diamonds. The results indicate that increased channel boundary curvature can decrease the optimal distance between channels, and that the optimal boundary shapes of fully embedded channels can be non-rectangular. In particular, elliptic and nearly elliptic shapes are found to produce equivalent optimal thermal performance as rounded rectangular shapes under practical conditions.
Optimization of Twin Screw Compressor With a Software Package
Authors: Xing Ziwen , Peng Xueyuan , Shu Pengcheng , Cui Tiansheng 
Published: December 2021

Abstract
A software package for the design of twin screw compressors is introduced in this paper. Functions of its main program include profile generation, geometrical parameter calculation, performance simulation, dynamic analysis, rotor deflection calculation, and cutter shape calculation. It is shown that the design work of twin screw compressor can be done quickly and precisely with the help of this software package. It is also illustrated how to obtain an optimum design by making use of the package.
ABSIM: Modular Simulation of Advanced Absorption Systems
Authors: Grossman Gershon , Zaltash Abdi 
Published: December 2021

Abstract
The computer code ABSIM has been developed for simulation of absorption systems in a flexible and modular form, making it possible to investigate various cycle configurations with different working fluids. Based on a user-supplied cycle diagram, working fluid specification and given operating conditions, the program calculates the temperature, flowrate, concentration, pressure and vapor fraction at each state point in the system and the heat duty at each component. The modular structure of the code is based on unit subroutines containing the governing equations for the system’s components. A main program calling these subroutines links the components together according to the cycle diagram. The system of equations for the entire cycle is thus established, and a mathematical solver routine is employed to solve them simultaneously. Property subroutines contained in a separate database serve to provide thermodynamic properties of the working fluids.
The paper describes the current capabilities and recent improvements made to ABSIM along with examples of simulation results for several rather complex cycles, including lithium bromide-water double-, triple- and quadruple-effect cycles and ammonia-water GAX, branched GAX and vapor exchange (VX) cycles.