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The 3D parts printed by the laser powder bed fusion (LPBF) process may have the disadvantages of residual stress, part deformation, and surface roughness. Post-processing is usually required to improve such part characteristics. This study investigated the effects of ultrasonic vibration-assisted compression (UAC) on stainless steel 316L parts fabricated by LPBF. The morphology of the molten pools, microstructure, and hardness by UAC and conventional compression (CC) were evaluated. It was found that UAC was more likely to refine the molten pools than CC. The number of sub-grain boundaries near the compressive surface was increased significantly by UAC. Compared with the CC sample, the UAC-processed specimens showed an increased hardness of 7%.

Nowadays, microstructures have an important role in optical products as well as in optical systems. Beside machining methods, hot glass embossing is recently a novel technology to manufacture microstructures in optical components with high quality and low cost. Especially, this technology has been assisted efficiently by ultrasonic vibration. Previous studies showed that high energy of ultrasonic vibration would lead to the temperature rise inside the glass so that the material was easily embossed into the microcavities on the mold. Thus, micro-formability of glass material has been especially improved efficiently. However, there were no studies focusing on effect of ultrasonic vibration on embossing speed in this process. Therefore, this work is aimed to utilize ultrasonic vibration to improve the embossing speed of hot glass embossing process. K-PSK100 optical glass was used as the material for all experiments. Pyramid array with size of 30 × 30 × 20 μm and period of 150 μm was created on the mold. Microstructure hot embossing experiments were conducted for both conventional process (without ultrasonic vibration) and ultrasonic vibration-assisted process (frequency of 35 kHz and amplitude of 3 μm). By fixing the embossing temperature of 430 °C, the embossing speeds of 0.05 mm/min, 0.10 mm/min and 0.15 mm/min were applied, respectively. Experimental results showed that in case of conventional process, the faster embossing speed, the smaller final height of pyramid structures. Nevertheless, this obstacle was resolved by ultrasonic vibration. Under heating effect of ultrasonic vibration, the glass still filled well into the pyramid cavities on the mold even when the high embossing speed was applied. Measurements indicated that in the same experimental conditions (temperature and speed), ultrasonic vibration could improve the filling ability of the glass to 18 %. This finding could be used to optimize the experimental conditions to increase the productivity of the microstructure hot glass embossing process.

In this study, a series of experiments was conducted in order to investigate the mechanisms of tensile force reduction and martensitic transformation in SUS304 stainless steel during ultrasonic vib...

Formability in sheet forming processes are usually analyzed by standardized tests, which often requires different test equipment associated with high initial investment cost. The present study purposes a flexible test tooling system for hydraulic bugle test apparatus that allows to evaluate the impact of size effect on the formability of thin metallic sheets. Finite Element Method was used for concept and design of the tooling system and experimental tests were carried out with thin sheets of SUS316L stainless steel to assess the overall performance of the tooling system.

Open reduction and internal fixation (ORIF) with plate is the standard treatment for displaced intra-articular calcaneal fractures. We constructed a three-dimensional complete foot finite element model, which was also modified to evaluate the biomechanical effect of Sanders IIB tongue-type calcaneal fracture treated by ORIF with locking plate. We compared plates with locking screws (LSs) and those with non-locking screws (NSs). Static standing was simulated by applying ground reaction force and the pulling force of the Achilles tendon. ORIF with plate using NS or LS provided good stability for Sanders IIB tongue-type calcaneal fracture and might allow light touch weight-bearing in the early postoperative period.

Hot glass embossing is a novel technology to manufacture microtips for Field Emission Displays with high quality and low cost. This technology recently has been assisted by ultrasonic vibration. Previous studies showed that high energy of ultrasonic vibration would lead to the temperature rise inside the glass so that micro-formability of glass material has been especially improved efficiently. However, these findings were experimental only. Therefore, this work is aimed to utilise the proposed model in the previous study to analyse the shape of pyramid structures on K-PSK100 optical glass substrate during ultrasonic vibration-assisted hot glass embossing process. Microstructure hot embossing experiments were first conducted without and with the assistance of ultrasonic vibration (frequency of 35 kHz and amplitude of 3 μm). Three-dimensional simulations were then performed to predict the height of pyramids after hot embossing process. The consistency between simulations and experiments not only pr...

Calcaneal fractures are the most common fractures of the tarsal bones. The stability of fixation is an important factor for successful reconstruction of calcaneal fractures. The purpose of this study was to analyze the biomechanical influence of plate fixation with different combinations of locking and nonlocking screws during early weight-bearing phase. A three-dimensional FE foot model was established using ANSYS software, which comprised bones, cartilages, plantar fascia, and soft tissue. Calcaneal plate was fixed with whole locking (WLS), whole nonlocking (WNS), and hybrid screw configurations for FE analysis. The WNS generated a 6.1° and 2.2° Bohler angle decrease compared with the intact model and WLS (WNS: 18.9; WLS: 21.1; intact: 25.0°). Some hybrid screw configurations (Bohler angle: 21.5° and 21.2°) generated stability similar to WLS. The FE results showed that the fragments at the posterior facet and the posterior tuberosity sustained more stress. This study recommends that the hybrid screw configuration with at least four locking screws, two at the posterior facet fragment and two at the posterior tuberosity fragment, is the optimal choice for the fixation of Sanders type IIB calcaneal fractures.

Ultrasonic vibration technology has recently been applied in high-temperature forming processes, such as hot upsetting and hot glass embossing. Experimental research has delineated the effects of ultrasonic vibration on reducing required forces and improving the formability of materials. The purpose of this study was to construct a finite element model of the embossing stage of the ultrasonic vibration-assisted hot glass embossing process. Traditional hot embossing experiments in which the embossing speed and temperature were varied were performed to calculate the viscoelastic dissipation caused by ultrasonic vibration, and this value was then inputted into the simulation. The consistency of the force responses in the experiments and simulation indicated that the proposed model is valid. The findings indicate that the influences of parameters such as the vibration frequency, vibration amplitude, and embossing speed on the ultrasonic vibration-assisted hot glass embossing process must be investigated further.

We used atomic layer deposition to form ZnO thin-film coatings on Si substrates and then evaluate the effect of pile-up using the nanoscratch technique under a ramped mode. The wear volume decreased with increasing annealing temperature from room temperature to 400 °C for a given load. Elastic-to-plastic deformation occurred during sliding scratch processing between the groove and film for loading penetration of 30 nm. The onset of non-elastic behavior and greater contact pressure were evident for loading penetration of 150 nm; thus, full plastic deformation occurred as a result of a substrate effect. We suspect that elastic–plastic failure events were related to edge bulging between the groove and film, with elastic–plastic deformation attributable to adhesion discontinuities and/or cohesion failure of the ZnO films.

This study examines the performance of printed circuit heat exchangers (PCHE) operated at high temperature subject to the influence of inlet conditions. Simulations are made with three cold plates and three hot plates with mass flow ranging from 0.469kg/h to 4.697kg/h. The inlet temperatures of the cold side and hot side are 200°C and 700°C, respectively. The size of the plate is 272×55×1.65mm with straight channel in the cold side and Z-Shape channel in the hot plate. The simulation is carried out for three cases (Case1: Vc = 5 m/s, Tc = 200 °C, Vh = 5 m/s, Th = 700 °C; Case2: Vc = 5 m/s, Tc = 200 °C, Vh = 10 m/s, Th = 700 °C; Case3: Vc = 1 m/s, Tc = 200 °C, Vh = 5 m/s, Th = 700 °C). It is found that the effect of inlet velocity on the temperature performance is quite significant, and the heat transfer coefficient is related to the mass flow rate. The distribution of mass flow rate within the channel casts significant effect on the outlet temperature. The calculated results indicated the effectiveness ε (Case1) is 0.72 which is much higher than those of Case2 (0.704) and Case3 (0.574).Yet the second cold plate shows the maximum temperature difference and the pressure drop in all three cases of simulation.

A new apparatus for an ultrasonic vibration-assisted glass hot embossing process has been developed. The upper die constitutes the ultrasonic vibrating device, and a cooler is provided to protect the transducer from the high operating temperatures. An ultrasonic horn originally designed for use at room temperature was modified to ensure correct operation of ultrasonic vibrating device for high temperature use. Because the load cell is located inside a vacuum chamber, the detection of the force applied to the glass during the forming process is not significantly impacted by external forces, and thus, a precise force history of the forming glass can be obtained. Flat hot embossing experiments were performed to investigate the effect of ultrasonic vibration on the amount of force required during forming, and Fresnel structure hot embossing experiments were then conducted to investigate the improvement in molding accuracy gained through ultrasonic vibration. The experimental results are taken to validate the manufacturing potential of the developed apparatus and the improvement in formability achieved by applying ultrasonic vibration.

Tube spinning is a metal forming process used to manufacture axisymmetric products. This study chose a seamless thick-walled steel tube to manufacture a high pressure vessel. Finite element analysis was successfully applied to the neck-spinning process of a thin-walled tube; however, previous research has not investigated the neck-spinning process of thick-walled tubes. Therefore, the aim of this research was to investigate numerically the neck-spinning process of thick-walled tubes at an elevated temperature. The commercial software Abaqus/Explicit was adopted in the simulation. This paper compares experimental and simulation results on thickness distribution and outer contour of the spun tube. During the final stage, the average deviations between the simulation and experiment were 6.74% in thickness and 4.97% in outer contour. The simulation results correspond with those derived in the experiment.

The Coflex device may provide stability to the surgical segment in extension but does not restore stability in other motion. Recently, a modified version called the Coflex rivet has been developed. The effects of Coflex and Coflex rivet implantation on the adjacent segments are still not clear; therefore, the purpose of this study was to investigate the biomechanical differences between Coflex and Coflex rivet implantation by using finite element analyses. The results show that the Coflex implantation can provide stability in extension, lateral bending, and axial rotation at the surgical segment, and it had no influence at adjacent segments except for extension. The Coflex rivet implantation can provide stability in all motions and reduce disc annulus stress at the surgical segment. Therefore, the higher range of motion and stress induced by the Coflex rivet at both adjacent discs may result in adjacent segment degeneration in flexion and extension.

Scroll-type compressors (STCs) are widely used in modern air conditioners for higher efficiency and durability. However, the internal leakage, caused during un-rating operated speed, reduces the volumetric efficiency and influences the performance of STCs. This paper has proposed an axial-compliant mechanism (ACM), composed of a suspension structure and a limiting ring, to solve the leakage problem of a low side STC running in extended speeds. The aim of this ACM design is to control the leakage by keeping optimum clearance. By integrating the verified STC performance simulation package with the internal leakage model, the optimum clearance between scroll tip and bottom plate has been investigated. After the numerical simulation, by employing suitable designs, an improved ACM prototype has been developed and tested. The experimental results show that low leakage, noise, and power consumption are achieved during compression processes even with extended operation speeds, and moreover, the overall coefficient of performance is increased from 0.61% to 13.53%. In this study, the proposed design is useful for enhancing the performance of low side type STCs.

The aim of this research is to investigate numerically the neck-spinning process of a tube at elevated temperature. The commercial software Abaqus/Explicit was adopted in the simulation. For the construction of the material model, special uni-axial tensile tests were conducted at elevated temperature and various strain rates, since the material is sensitive to strain rates at high temperature. The influence of the element type and mass scaling factor were investigated through numerical simulation. Full-integration shell element is the better choice in the simulation of the neck-spinning process at elevated temperature. The use of suitable mass scaling factor will make the analysis more efficiency. Comparisons between experimental and simulation results on thickness distribution and the outer contour of the spun tube are discussed. Good agreement was found between experimental and simulation results.

A homemade apparatus was used to apply ultrasonic-vibration to assist the glass hot embossing processes. To operate at high temperatures for glass hot embossing, the ultrasonic vibration system was appropri- ately designed with an embedded cooling system, and an ultrasonic horn was specifically modified for high- temperature use. Molds with both V-groove and Fresnel structures were manufactured for hot embossing experi- ments on PSK-100 glass. The heights of the molded structures were increased significantly with the assistance of ultrasonic vibration. This technology demonstrates the capability to upgrade the performance of the glass hot embossing process.

This research integrated finite element analysis (FEA) and optimum design to obtain a fast, accurate and automatic optimization system for the design of an ultrasonic horn. The optimization system was developed to achieve uniform amplitude distribution on the output surface of a block shaped horn for the ultrasonic plastic welding. Agreement between the experimental and numerical data proved that this optimization system was efficient in the design of ultrasonic horns.

In human motion analysis, in situ calibration of the force plate is necessary to improve the accuracy of the measured ground reaction force (GRF) and center of pressure (COP). Few existing devices are capable of both static and dynamic calibration of the usually non-linear GRF and COP errors, while are also easy to move and/or set up without damaging the building. The current study developed a small device (160 cm × 88 cm × 43 cm) with a mass of 50 kg, equipped with auxiliary wheels and fixing suction pads for rapid deployment and easy set-up. A PC-based controller enabled quick movement and accurate positioning of the applied force to the calibration point. Static calibration at 100 validation points and dynamic calibration of a force plate were performed using the device. After correction by an artificial neural network (ANN) trained with the static data from another 121 points, the mean errors for the GRF were all reduced from a maximum of 0.64% to less than 0.01%, while those for the COP were all reduced from a maximum of about 1.37 mm to less than 0.04 mm. For dynamic calibration, the mean errors for the GRF were reduced from a maximum of 0.46% to less than 0.28%, while those for the COP were reduced from a maximum of 0.95 mm to less than 0.11 mm. The results suggest that the calibration device with the ANN method will be useful for obtaining more accurate GRF and COP measurements in human motion analysis.

Tube spinning process is a metal forming process used in the manufacture of axisymmetric products and has been widely used in various applications. Finite element analysis has been successfully applied to the tube spinning processes, but no temperature effects have been considered on neck-spinning. For this reason, the aim of this research is to investigate numerically the neck-spinning process of a tube at elevated temperature. The commercial software Abaqus/Explicit was adopted in the simulation. For the construction of the material model, special uniaxial tensile tests were conducted at elevated temperature and various strain rates, since the material is sensitive to strain rates at high temperature. Comparisons between experimental and simulation results on thickness distribution and the outer contour of the spun tube are discussed. During the final stage, the average deviations between the simulation and experiment were 10.65% in thickness and 3.03% in outer contour. Good agreement was found between experimental and simulation results. The influence of the coefficient of friction, roller translation speeds, and the tip radius of the rollers were also investigated through numerical simulation.

In this article, we report an optical design for a light emitting diode that can achieve high illumination quality using two hyperbolic reflectors. The relative movements of the reflectors and the light source produce a zoom function that can change the illumination beam from convergence to divergence. This study uses optical software ZEMAX for system simulation, and optimization was performed to select reflector parameters with the objectives of both improving floodlight uniformity and spotlight efficiency. Finally, experiments were conducted to verify the validity of the design, and the results corresponded well to the zoom illumination simulations.

A geometric model of scroll profiles, constructed from an involute of circle with variable radii, has been developed by using the theorem of planar orbiting mechanisms. Parametric studies have also been investigated in this study. When compared to the conventional scroll profile with the same suction volume, volume ratio and housing size, this new model demonstrates better reliability and efficiency because of a lower wrap height. Alternatively, a scroll type compressor with a more compact housing size can be achieved by using this new profile but keeping its wrap height the same as the conventional one. Furthermore, arc and line modifications have been built to provide wider design varieties. These are used to avoid interference at the center of the scroll pair and to boost the volume ratio of this new scroll profile.

Clad metals are becoming increasingly emphasized in sheet metal applications. In this research, sheet hydroforming process (SHF) was adopted to improve the formability of Ti/Al clad metal sheets and SUS 304 metal sheets used in computer, communication, and consumer product housings. Both finite element simulation and experimental verification were carried out to investigate the deformation of blanks. Several significant process parameters, such as holding force, friction, counter pressure history, and blank dimensions, were discussed for improving the formability of the two metal sheets. In SHF simulation, a virtual film technique was proposed to realistically approach the hydraulic loading condition during SHF. Finally, the deformed shape and thickness distribution of parts manufactured with SHF were compared with the results of simulation. Good agreements were obtained.

Displacement-controlled finite element analysis was used to evaluate the mechanical behavior of the lumbar spine after insertion of the Dynesys dynamic stabilization system.This study aimed to investigate whether different depths of screw placement of Dynesys would affect load sharing of screw, range of motion (ROM), annulus stress, and facet contact force.In clinical follow-up, a high rate of screw complications and adjacent segment disease were found after using Dynesys. The pedicle screw in the Dynesys system is not so easy to implant into the standard position and causes the screw to protrude more prominently from the pedicle. Little is known about how the biomechanical effects are influenced by the Dynesys screw profile.The Dynesys was implanted in a 3-dimensional, nonlinear, finite element model of the L1 to L5 lumbar spine. Different depths of screw position were modified in this model by 5 and 10 mm out of the pedicle. The model was loaded to 150 N preload and controlled the same ROMs by 20, 15, 8, and 20 degrees in flexion, extension, torsion, and lateral bending, respectively. Resultant ROM, annulus stress, and facet contact force were analyzed at the surgical and adjacent level.Under flexion, extension, and lateral bending, the Dynesys provided sufficient stability at the surgical level, but increased the ROM at the adjacent level. Under flexion and lateral bending, the Dynesys alleviated annulus stress at the surgical level, but increased annulus stress at the adjacent level. Under extension, the Dynesys decreased facet loading at the surgical level but increased facet loading at the adjacent level.This study found that the Dynesys system was able to restore spinal stability and alleviate loading on disc and facet at the surgical level, but greater ROM, annulus stress, and facet loading were found at the adjacent level. In addition, profile of the screw placement caused only a minor influence on the ROM, annulus stress, and facet loading, but the screw stress was noticeably increased.

The cutting-stock problem, which considers how to arrange the component profiles on the material without overlaps, can increase the utility rate of the sheet stock. It is thus a standard constrained optimization problem. In some applications the components should be placed with specific orientations, but in others the components may be placed with any orientation. In general, the methods used to solve the cutting-stock problem usually have global search strategies to improve the solution, such as the Genetic Algorithm and the Simulated Annealing Algorithm. Unfortunately, many parameters, such as the temperature and the cooling rate of the Simulated Annealing method and the mutation rate of the Genetic Algorithm, have to be set and different settings of these parameters will strongly affect the result. This study formulates the cutting-stock problem as an optimization problem and solves it by the SQP method. The proposed method will make it easy to consider different orientations of components. This study also presents a global search strategy for which the parameter setting is easy.

This paper develops a design optimization procedure in scroll-type compressor (STC). By integrating the verified STC simulation model with an optimum solver, a frictional losses reduced problem of bearing components has been investigated. After the optimum search, the frictional losses can be reduced in range of 14.1–18.1% at all testing conditions with specified constraints. Herein, the design modifications of crank and upper bearings are compromised between reduction of frictional losses and maintenance of hydrodynamic lubrication. In addition, the narrower and shorter design of lower bearing and smaller one of thrust bearing can reduce frictional losses too. Furthermore, wider selection of materials in all the bearings can be adopted with the satisfied strength constraint. By using this procedure, various optimum combinations of parameters can be found for different STC design considerations.

In this research, the possibility of applying forming limit diagrams to the formability and fracture prediction of clad metal sheets is examined. The forming limits of clad metal sheets with different thickness combinations (e.g., A1050 1.0, 1.5, 2.0 mm/C1100 1.0 mm) are investigated via forming limits test (punch stretching tests). The true stress–strain curves of Al/Cu clad metal sheets are obtained through tensile tests. Using the experimental forming limit diagrams and the stress–strain curves, the fracture prediction of clad metal sheets are simulated by finite element analysis. Moreover, deep drawing tests are carried out to compare the experimental with the numerical results. These results can verify the accuracy of finite element model. Finally, significant differences in formability are found, and comparisons of the fracture prediction of clad metals with different initial thickness ratios are analyzed both numerically and experimentally.

The cutting-stock problem, which considers how to arrange the component profiles on the material without overlaps, can increase the utility rate of the sheet stock, and is thus a standard constrained optimisation problem. In some applications the components should be placed with specific orientations, but in others the components may be placed with any orientation. This study presents an overlap index and it is much more suitable for the active-set SQP method which can reduce the time spend for constraint consideration. Using this method, various object orientations can be considered easily and the number of object on the sheet stock can be improved by up to eight percent. & 2009 Elsevier B.V. All rights reserved.

This paper has constructed a bypass mechanism mathematical model in scroll-type compressor (STC) and has been integrated into a simulation package to predict the STC performance. The bypass mechanism, when added to a fixed scroll, is used to prevent over-compression and liquid slugging. Under five specified operating conditions, it was found that the STC with the bypass action increased the isentropic efficiency 2.5–10% more than the STC without the bypass action. Meanwhile, the calculated results of the developed model have been validated by a STC testing apparatus. In addition, it was found that the design of the bypass mechanism in the paper, can completely avoid over-compression and pressure discrepancy while the STC is in operation.

In this article, the design parameters of a cutting tool for manufacturing a rotary knife with multi-cutting angles have been studied. An objective function and constraints are defined, and optimized solutions are found by using two methods: global search and sequential quadratic programming. Hobbing and the concept of tooth undercutting were used to manufacture a rotary knife with multi-cutting angles. The proposed method not only improved the manufacturing efficiency over the traditional method (milling and grinding), but also significantly improved the strength of the rotary knife and the chip discharge ability, as shown by the finite-element analysis of the stress distribution and deformation of two different kinds of rotary knives.

Gear plunge shaving is one of the most efficient ways to finish gears. It has been a challenge for a long time to design and manufacture a plunge shaving cutter to induce gear tooth modification. This paper proposes a method for designing plunge shaving cutters to manufacture gears with modifications analytically. By integrating B-spline interpolation, differential geometry, and design optimization, the goal is achieved. Efficiency is greatly improved by avoiding the traditional trial and error method.

The aim of this research is to obtain an accurate material model for glass that can be used in finite element (FE) analysis of the glass molding process. A thorough understanding of the deformation behavior of the glass specimens was acquired by performing uniaxial compression tests. The elasto-viscoplastic model was utilized for the glass material at the molding temperature to construct the FE model, and a suitable set of parameters for this material model was verified by comparing the simulation results to the experimental data. As a result, the feasibility of the elasto-viscoplastic model for glass at the molding temperature was confirmed; this material model can be used in FE analysis of the prediction and modification of properties of the final lens products.

In the condition investigated here, a concentrated force is applied to both IC chip and blue tape bonded by an adhesive under pin–pin boundary conditions. The experimental results show that even though IC chips of 0.1 mm thickness are subjected to a concentrated force of 4.8 N, they cannot be fully separated from the blue tape and fail easily during the pick-up process. However, when IC chips of 0.34 mm thickness are subjected to a concentrated force of only 3.5 N, they can be fully separated from the blue tape without breakage. These two experimental findings are then explored analytically by applying the C++ program of the genetic algorithm associated with adhesively bonded joint analysis to the IC chip pick-up process. In accordance with the experimental results, the results for the 0.1 mm thick IC chips reveal no solutions for the material properties or adhesive thickness to satisfy the conditions of the IC chip successful pick-up process, although those for the 0.34 mm thick IC chips show solutions f...

Gear shaving is commonly used as a finishing process for gear manufacturing. The precision of the shaved gear tooth profile is highly dependent on both the parameter adjustments of the shaving machine and the cutter assembly errors. This paper develops the mathematical model of the shaved gear with crowning taking into account the setting parameters of the gear shaving machine and cutter assembly errors. The effects of the parameters on the work gear surface and the tooth lead crowning are also investigated. The results are thought to be relevant to the design, assembly, calibration, and control of a gear shaving machine.

This study focuses on the stress analysis of Mandibular Advancement Devices (MADs), which are considered as a standard treatment of snoring that promoted by American Academy of Sleep Medicine (AASM). Snoring is the most significant feature of sleep-disordered breathing (SDB). SDB will lead to serious problems in human health. Oral appliances are ensured in therapeutic effect and compliance, especially the MADs. This paper proposes a new MAD design, and the finite element analysis (FEA) is introduced to precede the stress simulation for this MAD., {"references":["National Sleep Foundation, 2005 Sleep in America Poll, National Sleep\nFoundation, Washington, DC, March 2005.","Mark C. Young, the Guinness Book of World Records 1998, Bantam\nBooks, New York, March 1998.","Society for Neuroscience, Brain Facts: A Primer on the Brain and\nNervous System, 5th ed., Society for Neuroscience, Washington, DC,\n2005.","David N. F. Fairbanks, Samuel A. Mickelson, and B. Tucker Woodson,\nSnoring and Obstructive Sleep Apnea, 3rd ed., Lippincott Williams &\nWilkins, Philadelphia, 2003.","Halstrom, \"Adjustable dental appliances for treatment of snoring and\nobstructive sleep apnea,\" United State Patent Number: 5365945, Filed:\nApr. 13, 1993.","Thornton, \"Apparatus for prevention of snoring and improved breathing\nduring sleep,\" United State Patent Number: 5427117, Filed: Sep. 29,\n1993.","Collins, Jr, \"Mandibular advancement appliance,\" United State Patent\nNumber: 5645423, Filed: Jun. 10, 1994.","Tomasi, \"Apparatus and method for reducing snoring and method of\nmaking same,\" United State Patent Number: 5313960, Filed: Nov. 4,\n1992.","Lowe, \"Mandible repositioning appliance,\" United State Patent Number:\n5409017, Filed: Jan. 19, 1994.\n[10] Thornton, \"Apparatus for prevention of snoring and improved breathing\nduring sleep,\" United State Patent Number: 5566683, Filed: Mar. 24,\n1995.\n[11] Fenton, \"Anti-snoring device with adjustable upper and lower relational\nmembers,\" United State Patent Number: 5499633, Filed: Mar. 28, 1994.\n[12] Parks, \"Device for alleviating snoring,\" United State Patent Number:\n5642737, Filed: May. 6, 1996.\n[13] Thornton, \"Device for improving breathing,\" United State Patent\nNumber: 5755219, Filed: May. 14, 1996.\n[14] Strong, \"Anti-snoring device and method of making same,\" United State\nPatent Number: 6418933, Filed: Jun. 15, 2001.\n[15] Buzzard RD, Buzzard LD, Kenyon PL, Agre BT, \"Universal,\nuser-adjustable oral cavity appliance to control snoring and reduce\nepisodes of obstructive sleep apnea,\" United State Patent Number:\n5570704, Filed: Dec. 20, 1994.\n[16] Thornton, \"Device and Method For Improving Breathing,\" United State\nPatent Number: 6305376, Filed: May. 16, 2000.\n[17] Gaskell, \"Dental device,\" United State Patent Number: 6845774, Filed:\nApr. 5, 2001.\n[18] Woo, \"Articulating connector for mandibular repositioning oral\nappliance,\" United State Patent Number: 6012920, Filed: Apr. 22, 1999\n[19] Robert G. Craig, John M. Powers, Restorative Dental Materials, 11th ed.,\nMosby, 2001.\n[20] H. Wada, M. Seika, T. C. Kennedy, C. A. Calder, K. Murase,\n\"Investigation of loading rate and plate thickness effects on dynamic\nfracture toughness of PMMA,\" 54(6), pp. 805-811, 1996.\n[21] M. Grujicic, H. Zhao, \"Optimization of 316 stainless steel/ alumina\nfunctionally graded material for reduction of damage induced by thermal\nresidual stresses,\" Material Science and Engineering, A252, pp. 117-132,\n1998.\n[22] MatWeb, Available: http://www.matweb.com/ , last visited on May. 1,\n2007.\n[23] T.A. Venkatesh, B.P. Conner, C.S. Lee, A.E. Giannakopoulos, T.C.\nLindley, S. Suresh, \"An Experimental Investigation of Fretting Fatigue in\nTi-6Al-4V: the Role of Contact Conditions and Microstructure,\"\nMetallurgical and Materials Transactions, 32A, pp.1131-1146, 2001.\n[24] Titanium Metric Fasteners Specification, Available at:\nhttp://www.ondrives.com/, last visited on May. 1, 2007.\n[25] Juliana Gomes dos Santos, Renata Garcia Fonseca, Gelson Luis Adabo,\nCarlos Alberto dos Santos Cruz, \"Shear bond strength of metal-ceramic\nrepair system,\" The Journal of Prosthetic Dentistry, 96, pp.165-173, 2006.\n[26] L. Mudford, R. V. Curtis, J. D. Walter, \"An investigation of bonding\nbetween heat-cured PMMA and titanium alloy (Ti-6Al-4V),\" Journal of\nDentistry, 25(5), pp.415-421, 1997.\n[27] A. Silvestre, A. Raya, M. Fernandez-Fairen, M. Anglada, J. A. Planell,\n\"Failure of acrylic bone cements under triaxial stresses,\" Journal of\nMaterials Science, 25, pp. 1050-1057, 1990."]}

In this study, a concentrated force is applied to both adherends bonded by an adhesive under pin–pin boundary conditions. First a mathematical model is derived with governing equations and boundary conditions. These complicated, and analytically problematic, coupled equations are solved numerically using symbolic manipulation and singular value decomposition (SVD). Also discussed are the effects of major factors, including the relative thickness of adherends, joint length and the action point of the concentrated force on the peel and shear stresses in the adhesive layer. This study identifies the conditions under which the upper adherend without breakage can be fully separated from the lower adherend. Particularly, it is found that the thickness of the lower adherend should be greater than ten times that of the adhesive layer but less than one-third that of the upper adherend, the adhesive layer should be relatively thin (h a ≤ 0.01 mm), and the adhesive joint should be relatively short (thickness to leng...

The traditional ultrasonic apparatus cannot be operated at high temperature, explaining why the effect of ultrasonic-vibration on high temperature metal forming has seldom been addressed in literature. This study establishes an ultrasonic-vibration hot upsetting system. A cooling mechanism is used to solve the problem of high temperature. The effects of temperature and strain rate during ultrasonic-vibration on the upsetting of aluminum alloy were explored using this new system. Experimental results indicate that ultrasonic-vibration can considerably reduces the compressive forces during hot upsetting. The reducing effect on compressive forces decreases while the temperature increases. The strain rate does not significantly affect the reducing effect on compressive forces.

This study conducts experiments on a planetary three-roll experimental apparatus and uses plasticine as the working material. Certain rolling characteristics were observed and compared with the data from finite element simulation, which include diameter of workpieces after deformation, the pitch length and threaded angle of spiral marks, and the cavity at the leading end of rolled plasticine. The comparison confirms the correctness of the simulation model for PSW.

In ultrasonic-vibration drawing, wires are drawn while ultrasonic vibration is applied to a drawing die. Prior studies provide experimental proof that ultrasonic-vibration drawing reduces drawing resistance, improves lubrication and prevents wire breakage. In the future, ultrasonic-vibration drawing is expected to contribute to the drawing of difficult-to-draw materials and operations, such as shaped wires, ultrafine wires, and the wire drawing operation in semidry or dry condition. However, a detailed analysis and understanding of the mechanism of improvement is not possible on the basis of conventional experimental observations because the ultrasonic-vibration processing phenomenon occurs at high speed. Therefore, we attempted to understand the processing mechanism of ultrasonic-vibration drawing using the finite element method (FEM). ABAQUS was used for the FEM. Drawing force and stress–strain distributions in drawn wires were analyzed. From these studies, we quantitatively clarified the mechanism of improved drawing characteristics, such as decreased drawing force.