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Automatically reconfigurable fixtures allow adaptation to geometry changes during manufacturing by repositioning contact elements or adjusting contact forces. Flexible suction cup grippers are widely used as contact elements because they adapt to curved surfaces of flexible workpieces. During gripping, the bellows and the sealing lip exert an unwanted force on the workpiece. This causes a deformation of low stiffness workpieces and affects the machining accuracy during fixture reconfiguration. This paper presents a simulation model and an algorithm to counteract the workpiece deformation in automatically reconfigurable fixtures caused by nonlinear stiffness of vacuum grippers during positioning through control of the vacuum. [ABSTRACT FROM AUTHOR]

Copyright of Electroplating & Finishing is the property of Electroplating & Finishing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study focused on the design of a specimen fixture which can be installed on the end of a conventional transmission bar so that shear testing (punch and double-notch) can be conducted with any conventional split-Hopkinson apparatus. The research was conducted by using the finite element method in Abaqus/CAE with 6061-T651 Aluminum as the specimen material. The research successfully determined the effect of the fixture's geometry and dimensions on the split-Hopkinson shear bar testing results. The optimum double-notch fixture provides great accuracy, having only a shear stress value difference of 1.49% with the original setup, while attaining force equilibrium after only 70 µs. The punch fixture, however, could only reach force equilibrium after 100 µs, thus providing too few observable data. Future work on the punch fixture is needed. [ABSTRACT FROM AUTHOR]

Concurrent transcranial magnetic stimulation (TMS) and magnetic resonance imaging (MRI) is time-consuming because of the limited space in the MRI bore and the sophisticated placement and orientation of the TMS coil to elicit the desired brain activities and behaviors. We developed a TMS coil holder capable of quick adjustment of the TMS coil position and orientation. The holder can also hold an MRI receiver coil array. A holder with one controlling knob, two omni-direction rotation joints, and two in-plane rotation joints was developed. Different TMS coil positions and orientations can be arranged and fixed in seconds. The holder can also accommodate two TMS coils to allow for multi-coil TMS-MRI. Our development significantly improves the workflow of the concurrent TMS-MRI in new neuroscience studies and clinical applications. [ABSTRACT FROM AUTHOR]

Thin-walled aluminium components are used in many sectors, including construction and aerospace. They are more resistant to deformation when subjected to a larger amount of grinding. As a result, the stability of the work components deteriorates, and the surface roughness rises. This paper suggests using a well-designed fixture with support heads to reduce deformation caused by square thin-walled aluminium plate milling. The support heads of the recommended fixture system are made of high-carbon steel. The milling experiment is carried out in a CNC Machining centre using machining parameters identical to those used in DEFORM 3D-Simulation. Surface roughness is measured using the SURFTEST SJ-210 portable Surface Roughness tester in two scenarios: without and with fixtures used during the milling operation. Surface roughness values are lowered by a minimum of 3% to a maximum of 19% as a result of using this fixture with support heads to reduce deformation. As a consequence, the suggested fixture with support head has been shown to decrease distortion in thin-walled aluminium plates. [ABSTRACT FROM AUTHOR]

TIG welding method is generally used for welding stainless steel and aluminum alloys. It is preferred for the welding of thin sheets due to its low heat input. The fact that the TIG torch does not deviate from the surface to be welded and the arc stability are extremely important factors for welding quality. For this reason, the use of fixtures is an important equipment for TIG welding work. In this study, a multivariable portable and fixed fixture is designed. There are suggestions for fixing the samples to be combined, minimizing the vibration problem and solutions based on heat input. The designed fixture has an adaptable for at least two-axis machines. Sheets of different lengths and widths can be easily welded with this technique without being exposed to distortion. However, copper planch and aluminum cooling fin are used in the method to reduce heat input. Semi-automatically welded 304L austenitic stainless steel sheet materials were compared with manually welded stainless steels and the results were evaluated.

Fixture is one of the important part of machining processes which use for enhancing the efficiency of the process. The conventional ginning clutch fixture is positioned with single fuse body on vertical machining centre. During machining, more time is consumed for loading and unloading which resulted high production time and cost. The solution to an industrial challenge of the design and fabrication of fixture is attempted in the present work. SolidWorks software is used for 3D modelling of novel fixture and stress analysis is performed using ANSYS software which determines the maximum stresses and deformation. Based on the ANSYS results, fixture is fabricated and use for further testing. The ginning clutch fixture was tested during production and was found that the efficiency of the production of ginning clutch was increased by 33%.

In today's world, many quality inspection applications require measuring a large batch of parts. In optical 3D metrology, an automated measuring cell helps maintain a high productivity. Producing fast, accurate and repeatable measurements requires securing the measured part in place, which is best achieved by using a fixture frame. This paper studies an existing design of such fastening device by reproducing and adapting it with the help of reverse engineering. The results show that adapting this design can lead to an increase in productivity and a reduction in cost. [ABSTRACT FROM AUTHOR]

Many mechanical parts used for various purposes, including medicine and information communication, have complicated and thin shapes owing to their functions and designs. To machine thin parts with high accuracy, it is necessary to reduce the cutting force induced on the workpiece or clamp the workpiece in an optimal manner. In this study, a support method capable of supporting the strength by using a magnetic elastomer is proposed. To test the effectiveness of the proposed support method, the use of the approach when applying a magnetic elastomer was compared with a method using a core, the low-melting point alloy, the low-melting point alloy and the elastomer. The effectiveness of the proposed method was clarified experimentally. [ABSTRACT FROM AUTHOR]

The production and repair of blades for aerospace engines and energy turbines is a complex process due their inherently low stiffness and damping properties. The final recontouring operation is usually performed by milling operations where regenerative chatter is one of the main productivity limiting factors. With the objective of avoiding specific stiffening fixtures for each blade geometry, this paper proposes a semi-active tuneable clamping table (TCT) based on mode tuning for blade machining. The active mode of the device can be externally controlled by means of a rotary spring and eddy current damping modules. Its in-series architecture allows damping to be introduced to the critical mode of the thin-walled part without any direct contact in the machining area and enables a more universal clamping. Its chatter suppression capabilities are maximized by means of a novel self-tuning algorithm that iteratively optimizes the tuning for the measured chatter frequency. The benefits of the iterative algorithm are validated through semidiscretization and initial value time-domain simulations, showing a clear improvement in blade recontouring stability compared to regular broad-bandwidth tuning methods. [ABSTRACT FROM AUTHOR]

Many manufacturing systems need more than one type of resource to co-work with. Commonly studied flexible job shop scheduling problems merely consider the main resource such as machines and ignore the impact of other types of resource. As a result, scheduling solutions may not put into practice. This paper therefore studies the dual resource constrained flexible job shop scheduling problem when loading and unloading time (DRFJSP-LU) of the fixtures is considered. It formulates a multi-objective mathematical model to jointly minimize the makespan and the total setup time. Considering the influence of resource requirement similarity among different operations, we propose a similarity-based scheduling algorithm for setup-time reduction (SSA4STR) and then an improved non-dominated sorting genetic algorithm II (NSGA-II) to optimize the DRFJSP-LU. Experimental results show that the SSA4STR can effectively reduce the loading and unloading time of fixtures while ensuring a level of makespan. The experiments also verify that the scheduling solution with multiple resources has a greater guiding effect on production than the scheduling result with a single resource. [ABSTRACT FROM AUTHOR]

With strengthening focus on digitalization and flexibility, active and flexible fixtures can provide the right tools for manufacturing systems. However, fixturing solutions are often too individualized for processes and need a universal approach. Firstly, a system formulation of multiple workpieces interacting with each other is presented. Secondly, strategies for direct and indirect force control along with their characteristics have been developed. The stability of assembly of force-controlled components has been analyzed, and certain key characteristics have been presented. The position control under different signal types, including oscillatory, have been discussed. Finally, a set of experiments have been conducted for performance evaluation. [ABSTRACT FROM AUTHOR]

Fixture errors are one of the error sources in machining operations. The fixture errors consist of positioning inaccuracies and errors due to workpiece and fixture deformations. Fixture locators’ height error causes incorrect positioning of the workpiece in the fixture and inaccuracy in machined surfaces which can be much more than the locators’ height error. For machining precise workpieces, it is necessary to eliminate these errors. This paper presents a method for modelling and compensating the fixture locators’ height error effect on workpiece machined surfaces. In this method, the planes of workpiece actual coordinate system (ACS) are mathematically modelled in the workpiece theoretical coordinate system (TCS). Using the model, required homogenous transformation matrix for coinciding ACS with TCS and modifying machining toolpath for compensating the errors is generated. The presented model is used to develop a post-processing fixture locator error compensation module, which can modify CNC machining codes to eliminate the effect of fixture locators’ height error on the workpiece machined surfaces. For verifying the presented method, machining simulations and cutting experiments have been performed in this work. The results show that the method can eliminate the effect of fixture locators’ height error on the workpiece machined surfaces considerably. [ABSTRACT FROM PUBLISHER]

This paper deals with the problems faced with the designing and planning of a sporting fixture considering correct referee assignments. A non-linear binary program model is proposed to solve the problems, which aims to minimize the sums of the differences that exist between the requirements of each match and the quality of the referee assigned achieving the design of the most adequate referee for each match. The efficiency of the proposed model is proved using some real data obtained from various fixtures for sports such as soccer, volleyball, and basketball. The mathematical model is solved by using CPLEX 12.7.0., which allows the automatic linearization of the problems. The results obtained demonstrate the efficiency of the proposed methodology for tackling problems, as well as its extension to other sporting disciplines, which require a similar type of planning. Similarly, given the robust nature of the proposed model, it is possible to implement other objective functions in accordance with the requirements of each league.

Permanent magnets due to their high energy production are widely used in a variety of electromagnetic devices. Such devices can be found in marine, aerospace, and robotic applications which require the minimization of weight and volume of the electro-magnetic devices. The coercively of some permanent magnets are high so the magnetizer is used for high magnetic field generation. Different parameters such as core shape, core material, turn number, cross section of the air gap, magnet type, etc have been known to affect the magnetizer operation. The amplitude and waveform of fixture current is obtained from PSPICE simulations and also experimental measurement. A 2D finite element analysis is developed to simulate magnetic fields and mechanical forces. The main parameters affecting optimal design of the magnetizer are discussed. Simulation results show that the core structure, air gap width, and turn numbers are the most important parameters when designing such a device. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering & Architectural Faculty of Eskisehir Osmangazi University / Eskişehir Osmangazi Üniversitesi Mühendislik ve Mimarlık Fakültesi Dergisi is the property of Eskisehir Osmangazi University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ege Üniversitesi Ziraat Fakültesi Dergisi is the property of Ege Universitesi, Ziraat Fakultesi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Because of the effects of gravity and/or residual stress, some manufactured mechanical parts, such as sheet metals and skins, often have a significantly different shape in a free-state position as compared to their state-of-use position. These parts are described as compliant, flexible or nonrigid. Expensive specialized fixtures are currently used prior to performing geometrical inspection operations in order to maintain compliant parts in the state-of-use position. This paper introduces an automatic bi-criterion flexible registration method for the dimensional and geometric inspection of such parts. The proposed method deforms the data acquired via a non-contact scanner of a compliant part in a free-state position until it reaches the nominal CAD shape for inspection with conventional Computer-Aided Inspection (CAI) tools. In other words, the method neutralizes the deviations induced in a compliant part by the effects of gravity and residual stress, allowing the acquired data to be treated as if it were obtained from a rigid part, using already available conventional (rigid) CAI tools. A proposed algorithm based on the BOFR-2 (the 2 nd version of a B i- O bjective F lexible R egistration algorithm) method is validated against both virtual simulated and experimental real industrial case studies from the aerospace sector. The resulting cost reduction and agility increasing make this fixtureless method well adapted to the requirements of unit-batch production in the context of Industry 4.0. • A fast fixtureless inspection method for profile and localization manufacturing errors in compliant parts. • Designed for a fast filtering step that identifies and locate unconformities. • The flexible registration is obtained by a Bi-objective strain and distance optimization of Coherent Point Drift parameters. • Validated on both virtual (simulated) and experimental (real) industrial case studies with promising results. [ABSTRACT FROM AUTHOR]

Thin-walled fibre reinforced composites like carbon fibre reinforced plastics are very susceptible to strength reductions due to low-velocity impact damages. In aerospace engineering, the dominating failure mechanisms of impact damaged composite structures are usually investigated based on the compression after impact (CAI) test procedure. This enables the determination of the influence of impact damages on the static residual compressive strength. CAI testing procedures are typically applicable to composite plates with thicknesses larger than 3--4 mm. If thinner panels are used, they typically fail near one of the loaded edges of the CAI device, in particular the area of the free edge (which is needed for compressing the panel) and not within the free measuring area. As a consequence, the investigated samples cannot be used as valid tests for the evaluation of the residual strength in CAI testing. In order to enable an investigation of the residual strength of thin-walled plates in CAI testing, a CAI testing device is developed based on an available CAI fixture and a standardized one. For comparability reasons, this new device exhibits the same dimensions as standardized fixtures. It shows a significant improvement with respect to standardized devices concerning the measurement of mechanical behaviour during CAI testing. [ABSTRACT FROM AUTHOR]

This investigation compared the competitive demands, as quantified by game distribution and density characteristics, of the major British and European football leagues. Pairwise comparisons between leagues revealed that English Championship teams played more total games, two game weeks and had a higher game density than teams from all other leagues analysed: the English Premier League, Scottish Premiership, Scottish Championship, Spanish La Liga, German Bundesliga, Italian Serie A, French Ligue 1 and the Dutch Eredivisie (ES, moderate to very large). English Premier League teams played more two game weeks (ES, trivial to large) and Spanish La Liga teams had a higher game density (ES, trivial to moderate) in comparison to all leagues other than the English Championship. Dutch Eredivisie (ES, moderate to very large), German Bundesliga (ES, moderate to very large) and Italian Serie-A (ES, small to large) teams played the lowest total number of games. Dutch Eredivisie (ES, moderate to very large), Scottish Championship (ES, small to very large) and German Bundesliga (ES, trivial to very large) teams played the lowest number of two game weeks. Dutch Eredivisie (ES, moderate to very large), German Bundesliga (ES, small to very large) and Scottish Premiership (ES, small to very large) teams had the lowest game density. Competitive demands vary between the major British and European football leagues. Owing to high game densities, maintaining appropriate player workloads might be particularly challenging for teams competing in leagues with greater game distribution and density demands (English Championship, English Premier League, and the Spanish La Liga). Squad rotation might be warranted in these leagues to mitigate risk of player injury, illness, and temporal declines in performance. [ABSTRACT FROM AUTHOR]

Topology optimisation (TO) and Laser Powder Bed Fusion (LPBF) for the manufacturing of welding jigs used in automotive body shops shows high potential regarding material efficiency, weight reduction, and the integration of additional functions into the metal LPBF jig elements. For conventional series production, steel or aluminium jig elements are manufactured by using water jet cutting and machining processes, such as milling, drilling, and turning. To determine the economic efficiency of the topological optimised jig elements, the manufacturing costs for using LPBF with steel powder is compared to the costs for using conventional manufacturing processes. Based on the results, the application of TO and LBPF for jig elements is discussed. [ABSTRACT FROM AUTHOR]

Fixture and clamping technologies of automated production lines for structural components in vehicles turned out as the main cost driver with up to 29 % of total investment costs of the production equipment. Additionally, they limit the product flexibility for product variants and change requests during the product development process. Flexible production concepts, like jigless joining with component-integrated jig features (CJF) might be a promising approach to reduce component specific jig technology. Technical as well as economical aspects are investigated on a low-cost battery pack housing for electric vehicles and are compared to conventional concepts concerning annual production volumes. [ABSTRACT FROM AUTHOR]

In this study, the authors present the latest developments on the measurements for the shielding effectiveness (SE) of gaskets and materials in reverberation chambers (RCs). A variant method, where the insertion loss of the fixture is achieved from the SE of the fixture with no sample in the aperture is found; it is appropriate for gaskets and for any flat material having a sufficiently high reflectivity at least on one side. A simple and usable condition under which the simplest method for the SE measurements of gaskets and materials in RCs can be used is also given, as well as particular cases where it can be directly applied are shown. This method, whose applicability is enhanced in this study, can be used for gaskets and any flat sample. Such developments simplify measurement setup and associated procedures. Comparisons of results support the methods for the SE measurements of gaskets and material in RCs shown in this study. [ABSTRACT FROM AUTHOR]

Traditional calibration methods and measurement‐based de‐embedding processes require the design of calibration kits and measurement standards, and the processes are cumbersome and costly. Even the simple automatic fixture removal (AFR) with 2x‐through fixtures still needs a through line to extract the fixtures' characteristics, and there are some restrictions. With one‐port AFR (1xAFR), the open fixture's time domain response (TDR) could be gated and windowed, then extracted to fixture's through S‐parameter. When the fixture is connected to device under test (DUT), its response could be de‐embedded from the blended S‐parameter and the DUT's S‐parameter could be obtained. In this paper, the basic principle and extraction process of 1xAFR are described, and two measurement cases are demonstrated to verify 1xAFR's ease of use and accuracy. [ABSTRACT FROM AUTHOR]

The coating technology is integral part of industrial production. In the tooling field, coating is an essential part. For the vast majority of tooling materials today, a coating that has abrasion resistance, high hardness, high temperature stability, as well as overall wear resistance of the cutting edge is a matter of course and necessity. However, coating machines are designed for a maximum predetermined number of tools. It would be possible to increase the capacity of the coating machine by means of a jig designed specifically for the given machine with given kinematics. The topic of this article is the design of the jig for increasing the capacity of the coating PVD machine. The main part is the design and construction of the jig, where the construction of the movement system is described. Then follows the design of the material and description of the main principle operation of the product. The jig will be designed for coating cylindrical tools, the monolithic milling cutters and drills made mostly of cemented carbide. When coating such tools with the PVD method, care must be taken to avoid so-called "shadow effects". This fact must also be reflected in the design of the fixture. Increasing the capacity of the PVD of the machine will lead to an increase in the production batch and thus an increase in profit. [ABSTRACT FROM AUTHOR]

The fixture is important process equipment in the automobile body assembly,and the reusability of fixture has become the key factor to hinder the efficiency of automobile production efficiency and assembly restructuring. For the automotive components of the sheet with different curvature radius,a set of reconfigurable modular fixture is designed. The sheet with different curvature radius is clipped,and it is not necessary to reconstruct the system,this is widely used in industrial production design standards. A modular fixture is designed,and its kinematics analysis is carried out to verify its rationality and stability.

Space payloads which installed on spacecraft such as satellites and airships are usually experienced random vibrations and low-frequency sinusoidal vibrations during launching. In this paper, a space payload cabinet is introduced, and the damping design is carried out by applying constrained viscoelastic damping layer to the surfaces of the cabinet to ensure that the space payloads can withstand the above-mentioned mechanical environmental conditions. A reliable connection between the space payload cabinet and the shaking table is achieved through the vibration test fixture. The basic requirements for the function and design of the vibration test fixture are presented. A method for detecting the dynamic characteristics of the fixture is proposed. The vibration characteristic of the space payload cabinet is simulated with the finite element software MSC.Nastran. Then the vibration test of the cabinet is conducted and the vibration response data is acquired by using the B&K test system. The test results show that the damping effect of the space payload cabinet is obvious after applying the viscoelastic constrained damping layer. [ABSTRACT FROM AUTHOR]

Some types of manufactured parts like sheet metals and skins often have a significantly different shape in a free-state position compared to their state-of-use position (as defined by their nominal CAD models) due to a combination of gravity and/or the residual effects of stress. Traditionally known as flexible (nonrigid compliant) parts, these dedicated fixtures are used for inspection operations in order to maintain flexible parts from a free-state position to a state-of-use position. This paper introduces a new automatic defect identification method primarily intended for two less-investigated manufacturing defect types: contour profile errors and hole localization. By combining simple techniques such as mesh boundary detection, fast boundary-based correspondence searches and accurate fast marching on triangulated meshes, the semi-geodesic distances from each boundary vertex on the acquired SCAN mesh to all the other boundary vertices is calculated, stored in a table and then compared to the corresponding values on the part's nominal CAD mesh. The comparisons found in the tables result in an estimation of the location and amplitude of the two aforementioned defect types. Compared to other work in this field, the overall approach does not rely on any mesh registration or finite-element analysis with tedious boundary conditions setup. It is also relatively fast. A fast algorithm/app based on this method was named the AFDA (Automatic Free-state Defect Approximation) and was validated against case studies in the aerospace sector. The results reflect the utility and effectiveness of the proposed approach. • A fast inspection method for contour and profile errors in compliant parts. • Comparison of semi-geodesic distances between contours on nominal shape and manufactured part loaded by gravity. • Designed for a fast filtering step that identifies and locate unconformities. [ABSTRACT FROM AUTHOR]

The goal of this study is to increase load capacity of interface contact between workpiece and machining fixture. Proposed methodology is based on pre-processing of contact interfaces and indenting the clamping elements into the workpiece. The pre-processing of workpiece/fixture contact interfaces is performed by microcutting. Applicability of the proposed clamping method has been verified by analysis, simulation, and experiment. Comparative analysis was performed for a conventional design of a clamping element with flat head, and a specially designed clamping element with ring-shaped head. In addition, clamping elements were comparatively analyzed regarding the different depths of the pre-established workpiece/fixture contact interface, i.e., for the different values of clamping forces as the result of contact interface pre-processing. Based on the results, it can be concluded that special clamping elements based on pre-processing and indenting of contact interface provide higher load capacity and lower contact interface compliance compared to their conventional counterparts, which are prevalent in today's industrial practice. In addition, the proposed method uses lower clamping forces to achieve deeper indenting and higher tangential load capacity. [ABSTRACT FROM AUTHOR]

Cutting force measurement is a crucial task aimed at improving process performance, since the cutting force contains important information about the condition of the process, such as tool condition and vibration. In the machining process of aircraft structural parts, the cutting force becomes a key factor which influences the qualified rate of product due to the low rigidity of aircraft structural parts. In order to monitor the cutting force, a novel force-sensing element integrated into the fixture system for aircraft structural parts machining is proposed. Accordingly, a cutting force measuring model of a force-sensing fixture system consisting of a set of the force-sensing elements is developed, enabling the estimations of not only overall cutting forces but also dynamic contact forces caused by the cutting forces at different locating/clamping points. To validate the effectiveness of the force-sensing element, a series of milling tests are conducted under both up and down milling with different cutting parameters, and the measured cutting forces are compared with a commercial dynamometer. Then, a series of analyses is carried out, and from the results, a satisfactory agreement with the forces measured by the dynamometer is achieved. Moreover, the median errors of the average resultant force are less than 6% compared with the dynamometer. [ABSTRACT FROM AUTHOR]