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An inter-digital capacitive (TDC) sensor has previously been used to measure dielectric properties of cable insulation polymer material when placed in direct contact with the insulation. Often cable insulation is covered by a polymer jacket. The dielectric properties of many cable jacket and insulation polymers are known to change due to thermal and radiation exposure-related damage. These dielectric properties frequently track with other measures of cable aging, such as tensile elongation-at-break and indenter modulus that have been broadly established as cable insulation polymer assessment methods. The external jacket of a cable is likely to have a different permittivity from the underlying insulation, and frequently the jacket material exhibits more severe damage than the insulation material due to environmental exposure. Because the jacket serves primarily to guard the cable during installation, as long as the underlying insulation condition is acceptable, the jacket condition is relatively unimportant in service.As part of a continuing program to develop and evaluate nondestructive examination methods that may be applied to cable condition assessment, a set of tools has been developed including (1) a parallel-plate sensor to directly measure the permittivity spectrum of flat sheet material and (2) an TDC and fixture to measure the effect of cable polymer dielectric property change on the sensor response. The TDC consists of two fork-like electrodes facing each other with the fork tines interspersed and separated by a small gap. The electrodes are printed on one side of a flexible substrate that can be conformed to the surface of a cylindrical cable, with tines parallel to the cable axis. The electrodes are connected to a broad-frequency-spectral impedance meter that senses the capacitance between the narrowly gapped electrode tines. This capacitance is known to vary as a function of the permittivity of any material in close proximity to the electrodes. By finite element modeling (FEM) and experimentation, this study investigates the effect of tine spacing and other design parameters associated with the TDC on the voltage (potential) distribution and electric field depth of penetration. The TDC measurement of an unshielded ethylene-propylene rubber (EPR)-insulated cable is shown to track with the degree of aging and quantities obtained by established methods. For jacketed cable systems, the TDC response is dominated by the jacket but, by analyzing measurements from TDC sensors with different depths-of-field penetration into the cable under test, the influence of the chlorinated polyethylene (CPE) cable jacket material degradation can be separated from an assessment of the cable insulation thereby enabling assessment of the insulation beneath/through the jacket.

The industrial sectors in Indonesia is currently growing very rapidly because it is supported by the development of technology in the field of manufacturing. One of the most frequently used machining operations in the manufacturing industry is welding operations. Welding operation is the most efficient and efficient method to combine two or more metal components. The product quality of welding can be obtained by using the production tool (fixture). The purpose of this research is to improve the quality of turbine runner product by using the welding fixture. The method was to design and make welding fixture of turbine runner welding, test the concentricity, straightness of the dish, the stability of the dish to the shaft, and the alignment of the blades to the shaft, and to analyze the deviation of measurement results. Based on the result of welding fixture design of cross-flow turbine runner component, a prototype welding fixture which can facilitate the assembling process of cross-flow turbine runner component was obtained. The conclusions of this research were: 1) The quality of the cross-flow turbine runner product can be increased along with the small geometrical deviation on cross-flow turbine runner using accelerator tool, 2). The maximum deviation of the runner disc placement to the axis of the axis on the 300mm diameter runner is 1.2mm and the runner of 200mm with diameter of 0.68mm, and 3). The assembling time of the turbine runner components is shorter using weld assembly tools with better accuracy.

The joining of two of any particular materials through friction stir welding (FSW) are done by a rotating tool and the work piece material that generates heat which causes the region near the FSW tool to soften. This in return will mechanically intermix the work pieces. The first objective of this study is to join aluminum plates and copper plates by means of friction stir welding process using self-fabricated tools and conventional milling machine. This study also aims to investigate the optimum process parameters to produce the optimum mechanical properties of the welding joints for Aluminum plates and Copper plates. A suitable tool bit and a fixture is to be fabricated for the welding process. A conventional milling machine will be used to weld the aluminum and copper. The most important parameters to enable the process are speed and pressure of the tool (or tool design and alignment of the tool onto the work piece). The study showed that the best surface finish was produced from speed of 1150 rpm and tool bit tilted to 3°. For a 200mm × 100mm Aluminum 6061 with plate thickness of 2 mm at a speed of 1 mm/s, the time taken to complete the welding is only 200 seconds or equivalent to 3 minutes and 20 seconds. The Copper plates was successfully welded using FSW with tool rotation speed of 500 rpm, 700 rpm, 900 rpm, 1150 rpm and 1440 rpm and with welding traverse rate of 30 mm/min, 60 mm/min and 90 mm/min. As the conclusion, FSW using milling machine can be done on both Aluminum and Copper plates, however the weld parameters are different for the two types of plates.

Welding and drilling are main processes of making chair frame from metal material. Commonly, chair frame construction includes many arcs which bring difficulties for its welding and drilling process. In UNS industrial engineering integrated practicum there are welding fixtures which use to fixing frame component position for welding purpose. In order to achieve exact holes position for assembling purpose, manual drilling processes were conducted after the frame was joined. Unfortunately, after it was welded the frame material become hard and increase drilling tools wear rate as well as reduce holes position accuracy. The previous welding fixture was not equipped with clamping system and cannot accommodate drilling process. To solve this problem, our idea is to reorder the drilling process so that it can be execute before welding. Thus, this research aims to propose conceptual design of modular fixture which can integrate welding and drilling process. We used Generic Product Development Process to address the design concept. We collected design requirements from 3 source, jig and fixture theoretical concepts, user requirements, and clamping part standards. From 2 alternatives fixture tables, we propose the first which equipped with mounting slots instead of holes. We test the concept by building a full sized prototype and test its works by conducting welding and drilling of a student chair frame. Result from the welding and drilling trials showed that the holes are on precise position after welding. Based on this result, we conclude that the concept can be a consideration for application in UNS Industrial Engineering Integrated Practicum.

Metal core printed circuit board (MCPCB) is the vital component that provides electrical and thermal support to ensure the Light-emitting diodes (LEDs) performs well. Most of the MCPCB shapes are designed according to the LED application fixture and housing. Thus the shape of MCPCB does not attract the attention for heat dissipation improvement. This study has exploited the open source software, Salome and Elmer for modelling and thermal simulation. Various shapes of MCPCB were investigated in this study and effect of the shape was outlined in the discussion session. The result shows that the isoperimetric inequality in the geometry of the MCPCB does influence the heat dissipation performance.

This paper is designed for bearing processing technology and fixture. The main task is to work out the half fine milling under 36mm, Φ18 holes, bearing the processing technology of the rules of procedure, and write CARDS. Its parts are casting, which is small and of simple structure. Moreover, the components of the hole processing is higher than that of the surface, so the processing order of surface first is taken. The fixture special jig is adopted in each working procedure, among which in a drill Φ18 holes, the hydraulic clamping is used, which is simple, convenient and can meet the requirements.

Small scale industry that produces several kinds of knive should increase its capacity due to the demand from the market. Qualitatively, this case study consisted of formulating the problems, collecting and analyzing the necessary data, and determining the possible recommendations for the improvement. While the current capacity is only 9 (nine), it is expected that 20 units of knife will produced per month. The processes sequence are: profiling (a), truing (b), beveling (c), heat treatment (d), polishing (e), assembly (f), sharpening (g) and finishing (h). The first process (a) is held by out-house vendor company while other steps from (b) to (g) are executed by in-house vendor. However, there is a high dependency upon the high skilled operator who executes the in -house processes that are mostly held manually with several unbalance successive tasks, where the processing time of one or two tasks require longer duration than others since the operation is merely relied on the operator’s skill. The idea is the improvement or change of the profiling and beveling process. Due to the poor surface quality and suboptimal hardness resulted from the laser cut machine for profiling, it is considered to subst itute this kind of process with wire cut that is capable to obtain good surface quality with certain range levels of roughness. Through simple cutting experiments on the samples, it is expected that the generated surface quality is adequate to omit the truing process (b). In addition, the cutting experiments on one, two, and four test samples resulted the shortest time that was obtained through four pieces in one cut. The technical parameters were set according to the recommendation of machine standard as referred to samples condition such as thickness and path length that affect ed the rate of wear. Meanwhile, in order to guarantee the uniformity of knife angles that are formed through beveling process (c), a grinding fixture was created. This kind of tool diminishes the dependency upon the operator’s skill as well. The main conclusions are: the substitution of laser cut with wire cut machine for the first task (a) could reduce the operation time from 60 to 39.26 minutes with good result of surface quality and the truing process (b) could be omitted; the additional grinding fixture in beveling process (c) is required and two workstations have to be assigned instead of one as in previous condition. They lead to improvements including the guarantee of the uniformity of knifes’ angle, the reduction on the operators’ skills dependency, the shortening of cycle time from 855 to 420 minutes, and the higher number of productivity from 9 units/month into 20units/month.

For rapid osseointegration of dental implant fixtures, various surface treatments including plasma spraying, hydroxyapatite coating, acid-etching, and surface grooving are used. However undesirable effects such as chemical modifications, loss of mechanical properties, prolonged processing times and post production treatment steps are often associated with these techniques. The osseointegration rate of the dental implants can be promoted by increasing the surface area of the dental implant, thus increasing the bone cells – implant material contact and allow bone tissues to grow rapidly. Additive Manufacturing (AM) techniques can be used to fabricate dental implant fixtures with desirable surface area in a single step manufacturing process. AM allows the use of Computer Aided Designing (CAD) for customised rapid prototyping of components with precise control over geometry. In this study, the dental implant fixture that replaces the tooth root was designed on commercially available software COMSOL. Nickel – ...

The paper investigates the effect of surface roughness on mixed mode loading fracture toughness of Arcan adhesive joint. The problem of crack within the adhesive joint is a great importance to various industrial applications and fracture toughness is an important parameter to determine the strength of adhesive joints by using various adherend roughness. The study of fracture toughness was performed by using two varieties of modified Arcan specimens such as coated and normal. The modified Arcan jig and it specimen was made for Mixed Mode fracture test of adhesive bonded joint and are capable to determine the perfect range of fracture toughness under pure Mode I, Mode II and Mixed Mode loading condition. Furthermore, it is also used to analyse the crack propagation and effects of adherend with crack length of 5mm with adhesive thickness of 6mm. The Araldite (Huntsman) adhesive ratio 1:1 (Part by weight) was used to bonded specimen in special fixture, in which by varying the loading angle of 0°, 45° and 90. ...

This paper presents the development of complex permeability measurement set up for characterization of specially ferrites & garnets to be used in ferrite circulator development, and other high frequency applications. Set up consists of 8714 ES network analyzer, in house developed movable short coaxial fixture, and complex mode calculation software for automatic measurement of the complex permeability over a wide frequency range of 300 kHz to 3 GHz.

An indigenously developed brazed joint of Al/Ti was characterized by ultrasonic C-scan method. The study revealed certain debond locations in the brazed joint. These debond locations would have resulted due to the failure of filler material’s joining ability. In spite of certain amount of load applied on the braze base metals, the above debonding happened. The debond locations further confirm that the pressure was not sufficient and therefore the debonds are present at exactly the same location where there were gaps in the fixture. Further analysis revealed that these debonds were present at the interface between the braze material and Al-plate. It is concluded that ultrasonic C-scan can be effectively used to evaluate the bond characteristics in a brazed joint between dissimilar metals.

Quality of machined parts mainly depends on the manufacturing process. Fixtures are used to hold the workpiece during machining and a typical machining fixture consists of locators and clamps. In a typical machining process the workpiece is first made to contact all the locators by applying clamping forces and then the machining forces are applied. Due to these forces, the workpiece fixture contact point is elastically deformed and the workpiece position is altered. This rigid body motion results in workpiece positional error, which, in turn causes machining error. Contact deformation and workpiece positional error depends on the reaction forces developed at the contact points. The reaction forces largely depend on the contact friction at these points and hence the effect of the same has to be investigated. The objective of this paper is to study the effect of contact friction on contact forces and final machining error of the workpiece. Results show that the contact friction has a definite influence on the machining error of the workpiece. The influence however depends on the cutting conditions and the fixture layout.

The State Space modelling approach has been recently proposed as an engineering‐driven technique for part quality prediction in Multistage Machining Processes (MMP). Current State Space models incorporate fixture and datum variations in the multi‐stage variation propagation, without explicitly considering common operation variations such as machine‐tool thermal distortions, cutting‐tool wear, cutting‐tool deflections, etc. This paper shows the limitations of the current State Space model through an experimental case study where the effect of the spindle thermal expansion, cutting‐tool flank wear and locator errors are introduced. The paper also discusses the extension of the current State Space model to include operation variations and its potential benefits.

This paper covers the dynamic response of rectangular (25.4×101.6×3.175 mm) specimens manufactured from layers of TiB/Ti. The layers contained volume fractions of TiB that varied from 0 to 85% and thus formed a functionally graded material. Witness samples of the 85% TiB material were also tested to provide a baseline for the statistical variability of the test techniques. Static and dynamic tests were performed to determine the in situ material properties and fundamental frequencies. Damping in the material/ fixture was also found from the dynamic response. These tests were simulated using composite beam theory which gave an analytical solution, and using finite element analysis. The response of the 85% TiB specimens was found to be much more uniform than the functionally graded material and the dynamic response more uniform than the static response. A least squares analysis of the data using the analytical solutions were used to determine the elastic modulus and Poisson's ratio of each layer. These resu...

Circumferentially guided ultrasonic Shear Horizontal wave Electromagnetic Acoustic Transducer pairs in a through‐transmission mode were used for detection and characterization of mechanical dents on the outer surface of a pipe from inside. A mobile fixture with a resolver is designed for the EMAT probes so that the sensor positions and waveforms are recorded as the platform goes through the pipe. Safety critical “cup” dents and relatively benign “saucer” dents of 25% of wall thickness and deeper were successfully detected and classified with the n1 mode SH wave and a support vector machine classifier. Dent depth estimation is also possible with a signal energy correlation approach.

Several methods are available for the generation and reception of Rayleigh waves on a part surface. The use of the so‐called “comb” is one method, where the comb elements or “fingers” contact the surface with a spacing between adjacent fingers equal to the Rayleigh wavelength of the substrate for a given frequency. Although efficient and simple, a fixed pitch comb is typically useful only at one frequency for a particular substrate. A simple “parallel link” fixture has been developed where the pitch of the fingers can be varied over a range of spacings, allowing the operator to set the comb pitch for a particular material/frequency at will. The comb elements may be glued to the wear plate of a longitudinal transducer or simply fluid coupled. Elements of the fixture and tests results of the fixtures used for generating Rayleigh waves on aluminum and steel substrates are shown.

Cast aluminum track shoes reinforced with metal matrix composite (MMC) inserts at heavy loading areas such as center splines and sprocket windows are light in weight, and can resist high temperature and wear. Various defects such as disbonds at the insert‐substrate interface, cracks and porosity in the MMC layer, etc. can be introduced during the manufacturing process and/or in service. This paper presents a portable ultrasonic system to automatically inspect tank track shoes for disbond. Ultrasonic pulse/echo inspection has shown good reliability for disbond detection. A prototype sensor array fixture has been designed and fabricated to prove the feasibility. Good agreements between the sensor fixture results and ultrasonic C‐scan images were obtained.

This paper reports the development, testing, and performance evaluation of spherically focused capacitive air‐coupled ultrasonic transducers 1 and 5 cm in diameter. A flexible micro‐machined copper/polyimide backplate permits a conformal fit to a spherically shaped fixture, forming the rear capacitor plate. A spherically deformed 6‐μm aluminized Mylar foil forms the front capacitor plate, completing the transducer. The device’s frequency spectrum is centered near 800 kHz with −6dB points at about 400 and 1200 kHz. The device’s focal‐plane behavior is successfully modeled theoretically as a focused piston radiator. The imaging and defect detection capabilities of the new transducer are demonstrated in a series of critical tests: a 250‐μm wire is easily imaged in a confocal geometry with a second device. Composite, honeycomb, and wood samples are imaged in through‐transmission C‐scans, showing internal defects. A printed circuit board is imaged, showing features as small as 200‐μm.

One of the essential characteristics of a superconducting wire is its critical current, defined as the maximal current at given temperature and magnetic field for which it remains superconducting. In order to make measurements from 1.8 K to 4.2 K and up to 1200 A at very low pressure, we studied and manufactured an original short sample mount; it is made of are two co‐axial current leads (46 mm and 24 mm of external diameter) terminating with two Nb3Sn buss bars. Annular space has been dimensioned in order to minimize the pressure drop for sub atmospheric operations (use of a 600 m3/h roots at 15 mbar with adjustable speed). The LHe supply is achieved with a transfer line covered with Kapton insulation. It is located inside the internal current lead and equipped with a JT valve. The sample to be measured, V A M A S type (Versailles project on Advanced MAterials and Standards), is assembled at the low end of the two buss bars. The quality of the electrical contacts is ensured by simple tightening. This pap...

An automotive underbody cross member was selected for one of the NUMISHEET’05 industrial benchmark to assess springback prediction capability of engineers around the world using various software. Binder and addendum were generated according to production intent process. Iterative design and draw simulation were performed on the part and addendum geometry to remove wrinkles and splits. Castings were poured and machined. Six different types of materials ranging from A15182‐O to DP965 were used in the production of the benchmark panels and three of these materials were included in the official benchmark data release. Draw panels were trimmed on a trimming fixture using laser and scanned with a whitelight optical device. Springback shapes at selected cross sections were recovered on the scanned data and original CAD data. In addition, major/minor and thickness strains were also measured at these sections.

An important aspect in the design of a good fixture is that of imparting sufficient rigidity to all the work piece surfaces that are to be machined. Work piece deformation during fixture set‐up and process operation is the most important consideration in the fixture design process. The present work aims at studying the effect of cutting forces and clamping forces on the workpiece. Prediction of deflection of the part under cutting loads and obtaining an optimal fix ture configuration could eliminate part rejects attributed to poor fixture design. The results of an analytical study to optimize the position of locators and clamps using a three stage procedure based on the Finite Element method is presented here. In the first stage, the optimal position for the base locators is determined with the objective being that of minimizing the deflection of the work piece. In the second stage, the position of the clamps and side locators and in the third stage, the clamping forces have been optimized. The work piece has been considered as a deformable body and the fixture elements as rigid members. Contact between the fixture elements and the work piece has been modeled using surface‐ to‐ surface contact elements and Coulomb friction assumed between contact surfaces. The deflection predicted by the analysis for various configurations of the base locators has been compared with the values that have been obtained experimentally using a test fixture. The results from the analysis and experiment follow the same trend and are comparable.

Nb3Sn strands being developed for future HEP applications have about four times the critical current at 4.2 K, 12 T, and significantly larger effective filament diameters than ITER‐class strands, upon which the present short‐sample testing protocol is based. Because of shortcomings in stability when testing these HEP strands with the ITER barrel, we have designed and built a new, low‐cost Nb3Sn short sample test fixture that provides excellent stability and allows for higher throughput at lower cost than the ITER design. The new design uses stainless steel as the central region of the barrel, but it can also incorporate Ti‐6A‐14V to produce different strain states on the strand upon cooldown. Soldering the modern Nb3Sn strand to the stainless steel barrel provided the best stability in experiments, where current‐voltage transitions were recorded up to 150 μV and up to ∼ 1000 A. Current‐voltage data were also obtained at fields as low as 8.5 T for state‐of‐the‐art HEP strands. A continuous round groove was...

Understanding the frictional contact behavior between fixture elements and the workpiece helps improve the Fixturing layout leading to better dimensional accuracy and geometric integrity of machined parts. It also affects the machining process dynamics and stability. The tangential (friction) force on the workpiece/fixture contact surface plays an important role in fixture design as it can be utilized to reduce the number of fixture components, thereby exposing more of the workpiece features to machining operations and providing a damping mechanism to dissipate input energy from machining forces out of the workpiece/fixture system. Therefore, proper modeling of the workpiece/fixture contact requires the modeling of friction conditions. The nonlinearity of the problem arises, both from the variation of the extent of contact surfaces, interrupted nature of the cutting forces and the effect of friction. The workpiece/fixture frictional contact is modeled using the finite element method. This paper presents the results of an experimental investigation of the characteristics of workpiece/fixture contact and its implementation in a numerical simulation of face milling.

Testing the critical current of superconducting cables under compression is a means to assess the performance of the final magnet. However, these cable tests are complicated and expensive. A fixture to assess the superconducting performance of a Nb3Sn strand within a reacted and impregnated cable under compression was designed and built. It is currently being commissioned. This device was designed to operate in liquid helium at 4.2 K and in high magnetic fields. A cable sample is compressed between two plates. A hydraulic cylinder mounted on the top flange allows applying a pressure up to 200 MPa to the cable sample. The copper current leads to the sample were designed to carry 2000 A. This paper illustrates the fixture assembly, describes the analyses performed, details the cable sample preparation, and shows preliminary test results.

A better understanding of thermal cook‐off is important for safe handling and storing explosive devices. A number of safety issues exist about what occurs when a cased explosive thermally cooks off. For example, violence of the events as a function of confinement is important for predictions of collateral damage. This paper demonstrates how adjacent materials can be gauged to measure the resulting pressure wave and how this wave propagates in this adjacent material. The output pulse from the thermal cook‐off explosive containing fixture is of obvious interest for assessing many scenarios.

Previous efficiency measurements [1] have highlighted that to accurately measure and predict thermophotovoltaic (TPV) integrated cell or array efficiencies, a thorough understanding of the system is required. This includes knowledge of intrinsic diode and filter characteristics, radiative surface properties of all materials used within the cavity, and an intimate knowledge of the radiator/photon source. As a result of these and other lessons learned, the cavity test fixture used in earlier experiments was redesigned. To reduce radiator temperature gradients, the radiator was oversized and thickened, cavity walls were eliminated, the diode heat sink and shielding material were separated, and the cold side was redesigned to incorporate a steady state heat absorbed measurement technique. This redesigned test fixture provides an isothermal radiator and significantly enhances calorimetry capabilities. This newly designed cavity test fixture, in conjunction with the Monte Carlo Photon Transport code RACER-X, was used to improve and demonstrate the understanding of “in-cavity” TPV diode/module system efficiency testing. A single TPV diode was tested in this new fixture and yielded good agreement between measurements and predictions.

Acoustic and vibration measurements were conducted at the Naval Undersea Warfare Center’s Seneca Lake Facility to investigate the in situ signal response of a linear array of velocity sensors (sensors that measure either acoustic particle acceleration, velocity, or displacement have generically been denoted as velocity sensors) on a coating. The coating used at Seneca Lake consisted of air‐voided elastomeric tiles with an overall coating thickness of approximately 3 inches. The accelerometer array and coating were mounted on the Seneca Lake Hull Fixture, which measures 33 feet lengthwise with an arc length of 20 feet. The fixture weighs approximately 30 tons. Specifically, measurements of in situ sensitivity, velocity reduction, reflection gain, array beam response, and equivalent planewave self‐noise levels are presented.