Journal articles on the topic 'Base-plate joint'
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1
Yan, Hong, Xianze Nie, Lei Zhang, Feng Yang, Mojia Huang, and Tengfei Zhao. "Test and Finite Element Analysis of a New Type of Double-Limb Double-Plate Connection Joint in Narrow Base Tower." Materials 14, no. 20 (October 10, 2021): 5936. http://dx.doi.org/10.3390/ma14205936.
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The connection between the leg members and diagonal members of the urban transmission line tower is mostly in the form of single-limb connection. This paper puts forward a new connection form of pipe double-limb double-plate connection joint, which is based on the model of key joints in an urban narrow base tower structure. The traditional pipe single-limb single-plate and new pipe double-limb double-plate joint are analyzed and studied from three aspects of theory, numerical simulation and experimental study. Through finite element analysis, it is obtained that the section stress of angle steel under eccentric load is 2.05 times of that under axial load, which is basically consistent with the 2.5 times of the theoretical calculation. This shows that the stress of the angle steel in the pipe double-limb double-plate joint is greatly reduced as the axial stress component, which can ensure the safety of the angle steel. Based on the theoretical analysis of the tensile force of two kinds of joints, through the test research and corresponding numerical simulation of pipe single-limb single-plate and pipe double-limb double-plate joints, under the same load, compared with pipe single-limb single-plate joints, the pipe double-limb double-plate joints designed in this paper can greatly reduce the stress of connection plates and members, and compared with the existing joint forms, the bending stress of joint plates can be reduced by about four times, which greatly improves the bearing capacity of the joint. The research on the pipe double-limb double-plate connection joint will provide the basis for the design of new connection joints of narrow base towers in urban areas.
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Karetnikov, D. V., A. S. Tokarev, A. V. Yakhin, and A. M. Fairushin. "Study of corrosion resistance of friction welding joints between tubes and tube plate." Journal of Physics: Conference Series 2373, no. 7 (December 1, 2022): 072017. http://dx.doi.org/10.1088/1742-6596/2373/7/072017.
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Abstract The cost of production and reliability of shell-and-tube heat exchangers is mainly determined by the features of the tube bundle and the joint between tube and tube plate (TTP) in particular. This paper provides a comparative analysis of the weld structure and electrode potential distribution of weld joints and base metal seams simulating the joint between heatexchange tube and tube plate (steel 5CrMo16) using the following welding methods: manual metal arc welding, gas tungsten arc welding and rotating friction welding. Comparison between macro- and microstructures of certain zones of tested welded joints, as well as values of electrode potential at specific points of the base metal and welded joints obtained by various methods, made it possible to conclude the effectiveness of application of specific ways of welding by their effect on corrosion resistance of given assembly.
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DURHAM-SMITH, G., and G. M. MCCARTEN. "Volar Plate Arthroplasty for Closed Proximal Interphalangeal Joint Injuries." Journal of Hand Surgery 17, no. 4 (August 1992): 422–28. http://dx.doi.org/10.1016/s0266-7681(05)80267-0.
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The anatomy and histology of the volar plate at the proximal interphalangeal joint and the mechanism of fracture/subluxation of the base of the middle phalanx in closed proximal interphalangeal joint injuries is reviewed. Our current technique of repair for these injuries and its evolution from Eaton’s original procedure is described. The results of 71 cases of volar plate arthroplasty performed over a five-year period for fracture/subluxations of the proximal interphalangeal joints are presented with follow-up ranging from six months to four years. 62 (87%) patients achieved a stable pain-free joint with a range of motion from 5° to 95° within two months. Complications were uncommon and correctable with an overall eventual patient satisfaction rate of 94%.
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Fu, Qinghong, Xianhua Chen, Degou Cai, and Liangwei Lou. "Mechanical Characteristics and Failure Mode of Asphalt Concrete for Ballastless Track Substructure Based on In Situ Tests." Applied Sciences 10, no. 10 (May 20, 2020): 3547. http://dx.doi.org/10.3390/app10103547.
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Asphalt concrete paved on the surface of a roadbed as a ballastless track substructure has an excellent waterproofing and vibration attenuation performance. However, the mechanical characteristics and the failure mode of this structure under the actions of a cyclic train load and ambient air temperature changes are still unclear. Therefore, a test section of an asphalt concrete substructure was constructed based on a high-speed railway ballastless track project in north China. In situ forced vibration tests and temperature-induced deformation monitoring tests were performed to investigate the mechanical responses of the asphalt concrete, respectively. Test results show that the bottom of the asphalt concrete layer is in the tensile state under the action of the cyclic train load. The surface of the asphalt concrete in contact with the base plate is subjected to tensile stress near the expansion joint under the action of the negative temperature gradient. Changes in the ambient temperature lead to more significant mechanical responses of the asphalt concrete substructure than the cyclic train load, especially near the expansion joint of the base plate. Therefore, the passive tensile failure mode may occur near the expansion joint of the base plate. However, it has also proved that setting isolation layers under the base plate near the expansion joint is an effective method to significantly reduce responses near the expansion joint in this research.
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Dhamotharakannan, Thirumalaikkannan, Paramasivam Sivaraj, M. Seeman, and Visvalingam Balasubramanian. "Mechanical and Metallurgical Characteristics of Rotary Friction Welded Low Carbon Steel Plate/Rod Joints." Key Engineering Materials 934 (November 28, 2022): 153–60. http://dx.doi.org/10.4028/p-51a271.
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This work aims to study the mechanical properties and microstructural characteristics of rotary friction welding of the unsymmetrical (plate/rod) joints of AISI 1018 low carbon steel plate and AISI 1020 low carbon steel rod. The mechanical properties (tensile properties and hardness) were studied. The fractured surface of the tensile specimen was examined by Scanning Electron Microscope (SEM). The tesnile properties (strength and elongation) are higher than the AISI 1018 plate but slightly lower than the AISI 1020 rod due to coarse ferrite grains in the HAZ region of the AISI 1018 plate. The hardness varied from the fully deformed zone (FDZ) to the base metal. The average value of the ultimate tensile strength of the friction welded joint is about 452 MPa. The average value of hardness at fully deformed zone is about 252 Hv, which 32% higher than the base metal.
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Guo, Kang, Guoqing Gou, Hang Lv, and Meile Shan. "Jointing of CFRP/5083 Aluminum Alloy by Induction Brazing: Processing, Connecting Mechanism, and Fatigue Performance." Coatings 12, no. 10 (October 16, 2022): 1559. http://dx.doi.org/10.3390/coatings12101559.
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Carbon fiber reinforced polymer (CFRP) is widely used in the lightweight design of high-speed trains due to its high specific strength. In order to further reduce the weight of the high-speed train body, it is necessary to study the joining process and fatigue properties of CFRP/aluminum alloys (CFRP/Al) structure. In this work, the CFRP plate and 5083P-O aluminum plate were successfully connected by an induction brazing method. The optimum parameters of induction brazing were determined to be an induction temperature of 290 °C, a normal pressure of 200 kPa, and a holding time of 5 s. After the 5083 plate was pre-anodized, the tensile strength of the CFRP/5083 joint reached a maximum value of 176.5 MPa. The anodization process introduced more surface micro-structures on the 5083 plate, leading to a better wetting behavior between CFRP and oxide film. Meanwhile, a new chemical bond, Al-O-C, was also formed at the interface of the CFRP/5083 joint. The fatigue limit of the CFRP/5083 joint was calculated to be 71.68 MPa through high-cycle fatigue (HCF) testing. The fatigue cracks initiated from the interface of CFRP/oxide film, and then propagated to base metal. Finally, the oxide film was peeled off from the base metal under shear stress, which contributed to the fracture of the CFRP/5083 joint. The bonding strength between CFRP and 5083 aluminum alloy is far from the conventional welded joints. Therefore, feasible approaches should be proposed to obtain a more robust bonding between CFRP and aluminum alloy in the future.
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Duan, Peng Yang, Dong Xing Wang, Guo Yan Zhou, and Shan Tung Tu. "Experimental Study on Peeling Properties of T Type Brazing Joint." Key Engineering Materials 795 (March 2019): 116–22. http://dx.doi.org/10.4028/www.scientific.net/kem.795.116.
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As the key component of the high temperature gas cooled reactor (HTGR), the performance of the plate fin heat exchanger determines the working efficiency and life of the HTGR. Although the plate-fin structure has lots of advantages such as high efficiency, compact structure, low manufacturing cost, its application will be affected by the vacuum brazing technology and harsh conditions, like high temperature and high pressure. In the practical application of plate-fin heat exchanger, the process of "splitting" between the fin and the diaphragm is very similar to that of the adhesive joint and the delamination of the composite. In the present study, a T-type specimen was designed for the the peel testing of brazed joints. Five kinds of specimens were designed based on the difference between the weld gap and the thickness of the sample base material. The tests were carried out under 450°C and 650°C at five kinds of loading rates, respectively. The peel force-displacement curves of standard samples were obtained . The maximum peel strength and average peel strength were calculated. In addition, the influence of base metal thickness, brazing gap, loading rate and test temperature on the maximum peel strength were analyzed by controlling variable method. Keywords: brazing joint; T-type peel test
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Kowalik, Marek, Tomasz Trzepiecinski, and Hirpa G. Lemu. "Effect of Pressing Parameters on the Quality of Joint Formation of Heat Exchanger Fins with the Base Plate." MATEC Web of Conferences 290 (2019): 03009. http://dx.doi.org/10.1051/matecconf/201929003009.
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In this paper, the results of experimental and numerical studies on joining the thin fins to the thick base plate of a heat exchanger are presented. The elements of the heat exchanger were joined by using developed method of press forming. The joining technology consists in clamping the sheet metal into the channel of the base plate using a punch with specific geometry. The effect of different configurations of the punch geometry (shape, radius and distance between fin and punch) and the indentation depth on the depth of the interface between the fin and base plate is analysed. Furthermore, the effect of different combinations of fin-base plate materials has been numerically studied. The plate material was the AA2219 -T851 aluminium alloy, while the fins were made of the AA5251 aluminium alloy. The elastic-plastic numerical computations of the joining process have been carried out using the finite element-based MSC.Marc program. It was found that the area of the contact of the fin with the base plate can be optimised by choosing the right parameters of the tool geometry and technological parameters. Experimental research has shown that increasing the punch indentation causes the material to flow in the transverse direction to the punch and the indirect extrusion in the region between the punches.
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Jeongung, Park, and Gyubaek An. "Dissimilar Welding of Low Alloy Steels Welded Joints: Effect of Run-Off and Run-On Plates." Metals 11, no. 4 (April 14, 2021): 642. http://dx.doi.org/10.3390/met11040642.
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The steel run-off plates attached at the start and end of a weld usually have the same material, shape, and groove as the base metal according to the rules for designing and constructing ship steel structures. However, rather than using the same grade of base steel, readily available steel is often used for these plates to increase material utilization. When using dissimilar grade steel as a run-off plate, the physical properties of the base metal may be diluted if the weld joint of the base plate is penetrated, thereby lowering the physical property value of the joint. If the physical properties of the welded part of the real structure are lowered because of the dilution of the properties of the dissimilar grade steel material, the safety of the entire structure can be affected. Therefore, in this study, analyses of the metal microstructure, hardness, impact, and chemical composition were performed on surfaces where the run-off plate was removed after welding to examine the effect of dissimilar run-off plate. The results of this study reveal that the properties of the run-off plate were not diluted toward the base metal and the Charpy impact value at the weld end was up to 48% greater than the impact value at the start of the weld at a temperature of −40 °C.
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Sun, Wei Hua, and Zhi Chao Bi. "Grade E550 Heavy Steel Plate by TMCP for Offshore Energy Exploration." Advanced Materials Research 936 (June 2014): 1146–52. http://dx.doi.org/10.4028/www.scientific.net/amr.936.1146.
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This paper introduces the study and production on steel plate of Grade E550 in60mm thick by Thermo-mechanical processing (TMCP) and tempering for offshoreinfrastructure purpose. The steel plate obtained high strength and goodtoughness in both the base materials and the weld joints. Microstructure and precipitation characteristicswere examined in the plate is comprised of bainite with a small amount ofpre-eutectoid ferrite. Parallel arranged lath bainite characterizes thebainitic structure with high density of dislocations and precipitates. Carbides MxCy averaging 200nm indimension and MC type Carbonitrides in several nano to a dozen nano carbidesdistribute in the bainite ferrite and the bainte lath interfaces. Compatiblemechanical properties were achieved at welded joint. Microstructures were analysed in the welding heataffected zone (HAZ).
11
Witono, Kris, Agus Setiawan, and Sugeng Hadi Susilo. "ANALISIS TEMPERATUR PELAT LANDASAN HOT-GAS WELDING DAN BENTUK BEVEL TERHADAP KEKUATAN TARIK LASAN HDPE." Jurnal Energi dan Teknologi Manufaktur (JETM) 5, no. 02 (December 30, 2022): 11–14. http://dx.doi.org/10.33795/jetm.v5i02.137.
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Welding has developed rapidly at this time, both for metallic and non-metallic materials, one of the methods used for plastic welding is Hot-Gas Welding. Plastic is a very difficult material to weld due to its low thermal conductivity. The quality of the mechanical properties of the existing plastic welded joints is not close to the strength of plastic objects without welding. The purpose of this study was to determine the effect of variations in the temperature of the base plate and variations in the shape of the bevel during the Hot-Gas Welding process on the tensile strength of HDPE sheet welded joints, to determine the conditions of the interaction between variations in the temperature of the base plate and variations in the shape of the bevel during the Hot-Gas Welding process. HDPE sheet welded joints that produce maximum tensile strength values. In this study, two independent variables were used, namely the base plate temperature (30,70,110,150 C), variations in bevel shape (V, X, U) and three controlled variables which included HDPE plastic material with a thickness of 5mm, using added filler material in the form of HDPE plastic with a diameter of 4 mm and a hot gun airflow heating temperature of 250℃. The tensile test standard uses the ASTM D 638-03 standard and for data processing is done by DOE factorial, as supporting data macrostructural photos of each weld joint are carried out. The results showed that the maximum tensile strength of HDPE welded joints was obtained at the temperature of the base plate of 150°C and the V bevel shape with a value of 18.46 MPa or 84.22% of the parent material
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Aboalriha, W. "Performance of Enhanced Steel Beam-Column Welded Connections for Seismic Resistance." European Journal of Engineering and Technology Research 6, no. 6 (September 22, 2021): 58–64. http://dx.doi.org/10.24018/ejeng.2021.6.6.2583.
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This paper presents and discusses the development of a numerical model which investigates the enhancement of overall stiffness and stress distribution in welded connections under cyclic loading. The structure under investigation, described in four fully welded T-joint (BCC5) specimens. The four specimens were modeled under different displacement loading using a finite element analysis program Solidworks and Ansys software in conjunction with test data obtained from the University of Lisbon, which was validated with the test results by matching the hysteresis loops, maximum high strain, and maximum stress at the crack location steel joint specimens. The comparison between the analysis and test results showed good agreement and also showed that the maximum strain in the enhanced model is less than the maximum strain on the base model, and the location of maximum strain is moved to the gusset plate rather than the weld zone, therefore the gusset plate makes the joint in the enhanced model more ductile than the joint in the base model. Life cycles to failure for the enhanced model are more than life cycles to failure in the base model. It is therefore found that this has useful applications in the steel construction industry.
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Aboalriha, W. "Performance of Enhanced Steel Beam-Column Welded Connections for Seismic Resistance." European Journal of Engineering and Technology Research 6, no. 6 (September 22, 2021): 58–64. http://dx.doi.org/10.24018/ejers.2021.6.6.2583.
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This paper presents and discusses the development of a numerical model which investigates the enhancement of overall stiffness and stress distribution in welded connections under cyclic loading. The structure under investigation, described in four fully welded T-joint (BCC5) specimens. The four specimens were modeled under different displacement loading using a finite element analysis program Solidworks and Ansys software in conjunction with test data obtained from the University of Lisbon, which was validated with the test results by matching the hysteresis loops, maximum high strain, and maximum stress at the crack location steel joint specimens. The comparison between the analysis and test results showed good agreement and also showed that the maximum strain in the enhanced model is less than the maximum strain on the base model, and the location of maximum strain is moved to the gusset plate rather than the weld zone, therefore the gusset plate makes the joint in the enhanced model more ductile than the joint in the base model. Life cycles to failure for the enhanced model are more than life cycles to failure in the base model. It is therefore found that this has useful applications in the steel construction industry.
14
Wu, Qiang, and Lan Ying Xu. "Study on Quality Control of the Laser Welding Joint." Applied Mechanics and Materials 442 (October 2013): 276–81. http://dx.doi.org/10.4028/www.scientific.net/amm.442.276.
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During laser welding process of high-strength galvanized steel, adopting guiding arc plate and the connecting arc plate can avoid harmful effect resulted in unstable melting width. The galvanized layer protecting joint is inevitably lost by having been burned, which affects stain resistance of welding joint. So salt water with the concentration of 3% is used in the corrosion test for the samples welded under different laser parameters, mass variation and metallographic microscopes are gained after joint being corroded. The test results indicate that the corrosion rates of the joint are different under different welding parameters during laser welding of high-strength galvanized steel; their average corrosion rates are coincident with that of base metal and laser welding technology hardly effect corrosion resistance of the joint.
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Park, SeongHwan, YoungHwan Joo, and Myungchang Kang. "Effect of Backing Plate Materials in Micro-Friction Stir Butt Welding of Dissimilar AA6061-T6 and AA5052-H32 Aluminum Alloys." Metals 10, no. 7 (July 10, 2020): 933. http://dx.doi.org/10.3390/met10070933.
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Thin sheets of lightweight aluminum alloys, which are increasingly used in automotive, aerospace, and electronics industries to reduce the weight of parts, are difficult to weld. When applying micro-friction stir welding (μ-FSW) to thin plates, the heat input to the base materials is considerably important to counter the heat loss to the jig and/or backing plate. In this study, three different backing-plate materials—cordierite ceramic, titanium alloy, and copper alloy—were used to evaluate the effect of heat loss on weldability in the μ-FSW process. One millimeter thick AA6061-T6 and AA5052-H32 dissimilar aluminum alloy plates were micro-friction stir welded by a butt joint. The tensile test, hardness, and microstructure of the welded joints using a tool rotational speed of 9000 rpm, a welding speed of 300 mm/min, and a tool tilting angle of 0° were evaluated. The heat loss was highly dependent on the thermal conductivity of the backing plate material, resulting in variations in the tensile strength and hardness distribution of the joints prepared using different backing plates. Consequently, the cordierite backing plate exhibited the highest tensile strength of 222.63 MPa and an elongation of 10.37%, corresponding to 86.7% and 58.4%, respectively, of those of the AA5052-H32 base metal.
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Ono, Takeyuki, Ryosuke Eto, Junya Yamakawa, and Hidenori Murakami. "Analysis and control of a Stewart platform as base motion compensators - Part I: Kinematics using moving frames." Nonlinear Dynamics 107, no. 1 (November 19, 2021): 51–76. http://dx.doi.org/10.1007/s11071-021-06767-8.
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AbstractKinematics and its control application are presented for a Stewart platform whose base plate is installed on a floor in a moving ship or a vehicle. With a manipulator or a sensitive equipment mounted on the top plate, a Stewart platform is utilized to mitigate the undesirable motion of its base plate by controlling actuated translational joints on six legs. To reveal closed loops, a directed graph is utilized to express the joint connections. Then, kinematics begins by attaching an orthonormal coordinate system to each body at its center of mass and to each joint to define moving coordinate frames. Using the moving frames, each body in the configuration space is represented by an inertial position vector of its center of mass in the three-dimensional vector space ℝ3, and a rotation matrix of the body-attached coordinate axes. The set of differentiable rotation matrices forms a Lie group: the special orthogonal group, SO(3). The connections of body-attached moving frames are mathematically expressed by using frame connection matrices, which belong to another Lie group: the special Euclidean group, SE(3). The employment of SO(3) and SE(3) facilitates effective matrix computations of velocities of body-attached coordinate frames. Loop closure constrains are expressed in matrix form and solved analytically for inverse kinematics. Finally, experimental results of an inverse kinematics control are presented for a scale model of a base-moving Stewart platform. Dynamics and a control application of inverse dynamics are presented in the part II-paper.
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Tanabe, H., Takehiko Watanabe, Y. Abe, and A. Yanagisawa. "Solid State Welding between CPTi and AZ31B Magnesium Alloy by Friction Stirring." Materials Science Forum 539-543 (March 2007): 3856–62. http://dx.doi.org/10.4028/www.scientific.net/msf.539-543.3856.
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This paper described an experimental study on the friction stir welding of dissimilar metal between commercially pure titanium (CPTi) and magnesium alloy AZ31B (Mg). Butt-welds produced at various tool rotation speeds were evaluated by the observation of the weld surface appearance, X-ray radiographic test, tensile test, SEM and EDX analysis. The main results obtained are as follows. Butt-joint welding of the CPTi plate to the Mg plate was easily and successfully achieved. The ignition of Mg occurred during welding at the tool rotation speeds over 1200rpm. The fragments of CPTi existed in a continuous form in Mg matrix. The tool rotation speed of 1200rpm attained the maximum tensile strength of a joint, which was about 75% of that of Mg base metal. Fracture occurred at the weld interface in most joint. EDX analysis revealed that Al in the Mg diffused into CPTi through the weld interface and MgO existed at the interface. It seems that the decrease in Al concentration in the Mg and MgO formation around the weld interface caused the low tensile strength of the joints.
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Phisitkul, Phinit, Vinay Hosuru Siddappa, Tinnart Sittapairoj, Jessica E. Goetz, Bryan D. Den Hartog, and John E. Femino. "Cadaveric Evaluation of Dorsal Intermetatarsal Approach for Plantar Plate and Lateral Collateral Ligament Repair of the Lesser Metatarsophalangeal Joints." Foot & Ankle International 38, no. 7 (April 11, 2017): 791–96. http://dx.doi.org/10.1177/1071100717702460.
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Background: Access to the plantar plate has been described using either a plantar approach or an extensive dorsal approach that required complete joint destabilization and often a metatarsal osteotomy. Clinical scenarios related to plantar plate tear vary and the pathologies in early stages are frequently limited to unilateral soft tissue structures; a less invasive operative approach may be possible. A novel approach requiring a release of only the lateral collateral ligament and the lateral half of the plantar plate is presented in this cadaver model; the extent of joint exposure possible is described. The ability to place a secure suture through the lateral collateral ligament and the plantar plate was analyzed. Methods: Nine fresh-frozen cadaveric specimens were dissected in a randomized fashion across the second to fourth metatarsophalangeal joints through the intermetatarsal space dorsally. Under distraction, soft tissue was sequentially released, including dorsal capsule, lateral collateral ligament, and the lateral half of the plantar plate. Integrity of the extensor tendons, deep transverse intermetatarsal ligament, proximal attachment of the plantar plate, and osseous structures was carefully preserved. The joint exposure was quantified after each step with sizing rods. Using a suture passer, 2-0 nonabsorbable braided sutures were passed into the lateral collateral ligament and the plantar plate, and the construct strength was measured using a tensiometer. Results: Progressive increase in mean joint exposure was noted after each step of soft tissue release with the final exposure of 6 mm after release of the lateral half of the plantar plate. Joint exposures after a capsulotomy and a lateral collateral release were 3 mm and 4 mm, respectively. Under distraction, the unilateral release of soft tissue created a lateral opening of the joint while the proximal phalangeal base adducted and medially deviated. Successful suture passage was noted in all specimens that could sustain a minimum tension of 25 N without a catastrophic failure. There was no statistically significant correlation with age, sex, foot length, and rays of the specimens when joint exposure was considered. Conclusion: The dorsal intermetatarsal approach appeared to be feasible for access to the lateral collateral ligament and the lateral half of the plantar plate. The average joint exposure of 6 mm allowed a quality suture passage by a suture passer in both structures in all specimens without the need of a metatarsal osteotomy. Clinical relevance: This operative approach may be appropriate for early stages plantar plate tear when only lateral soft tissue repair is needed. This technique should not preclude conversion to a more extensile operative approach or an additional metatarsal osteotomy if needed. Applicability of this operative approach in cases with more advanced pathologies or involving only medial soft tissue structures requires further studies.
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Luo, Chuan Hong, Wei Ping Peng, Ting Chen, and Fei Bo Dong. "Influence of Heat Treatment on Properties of 2219AA-T6 FSW Joints." Applied Mechanics and Materials 590 (June 2014): 187–91. http://dx.doi.org/10.4028/www.scientific.net/amm.590.187.
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The joint of 2219-T6 aluminum alloy plate was obtained by friction stir welding, and the microstructures and mechanical properties of the joint were investigated. The causes of the weakened joint strength in friction stir welding were analyzed and summarized correspondingly. The tensile properties show that the transverse tensile strength of the joint can reach about 70% of the base metal. Through the heat treatment of recrystallization with high temperature and at short time, the joint can restore the ductility and eliminate the softening, which will improve the performance in mechanical intensity of the joint.
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Wang, Mingqiu, Naiwen Fang, Laibo Sun, Pengbo Wu, Ruisheng Huang, Kai Xu, Xingxing Wang, et al. "Study of the Microstructure and Properties of the Butt Joint of Laser-Welded Titanium Alloy with Flux-Cored Wire." Metals 13, no. 2 (February 12, 2023): 369. http://dx.doi.org/10.3390/met13020369.
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A self-developed Ti-Al-V-Mo system titanium alloy flux-cored wire was used to join the Ti64 titanium alloy plate via laser welding with filler wire. The microstructure and properties of the obtained welded joint were investigated. The results showed the WM (welded metal) of the welded joint consisted mainly of acicular α’ martensite, and the HAZ (heat affected zone) was comprised of a primary αp phase, Widmanstatten, and a few α’ martensite and a residual β phase. The strength and elongation of the welded joint after breaking are equivalent to that of the BM (base metal). The tensile fracture, presenting as a microvoid coalescence ductile fracture, was encompassed by massive shear lips with deep and uniform dimples. The overall microhardness of the welded joint was sequenced as WM > HAZ > BM. In the WM, large-angle grain boundaries with intragranular misorientation greater than 15° accounted for about 84%. By XRD, it was discovered the welded joint was mainly composed of the α’ martensite, with a modest amount of extremely weak multi-angle α phase diffraction peak. The test results showed the designed welding method of titanium flux-cored wire and laser wire filling is suitable for high-quality welding of titanium alloy plate.
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Ji, Shude, Yue Wang, Zhengwei Li, Lin Ma, Liguo Zhang, and Yumei Yue. "Effect of Plate Thickness on Tensile Property of Ti–6Al–4V Alloy Joint Friction Stir Welded Below β-Transus Temperature." High Temperature Materials and Processes 36, no. 7 (July 26, 2017): 693–99. http://dx.doi.org/10.1515/htmp-2016-0012.
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AbstractDefect-free joint of Ti–6Al–4V alloy was successfully friction stir welded below β-transus temperature and then tensile tests were performed. Microstructure, macrostructure, tensile properties and fracture position are mainly discussed in order to investigate how surface indentation and plate thickness influence the tensile property. Weld zone (WZ) attained below β-transus temperature that owns better tensile strength limit than base metal (BM). During the tensile test, the elongation is decided by whether BM yields. Compared with friction stir welding joint using 2.5 mm thick plate, it is very difficult for joint using 2 mm thick plates to get bigger elongation due to surface indentation. Due to the higher tensile property of the WZ, the joint without surface indentation fractures at BM, reaching the 58.46 % elongation of BM.
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Kasir and Sulardjaka. "Mechanical and microstructural characterization of ST 37 butt joints by friction stir." MATEC Web of Conferences 159 (2018): 02037. http://dx.doi.org/10.1051/matecconf/201815902037.
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The aim of this research is to investigate mechanical and microstructure characteristic of ST 37 Friction Stir Welded (FSW) butt joints. The rolled plate of ST 37 steel was used as the base material. Tungsten carbide (20 mm on diameter) was used as the tool. The FSW process was conducted on a CNC milling machine. FSW joints were produced at 1500 and 2000 rpm of rotational speeds variation and the transverse speed is constan at 40 mm/min. Furthermore, the influence of rotational speed on the microstructure and mechanical properties of the joints were investigated based on parameters mentioned above. The tensile test was done based on JISZ 2241 standard. Microhardness was investigated based on ASTM E 384. Joint microstructure was also analyzed by optic microscopy. As a result, FSW joint at 2000 rpm tool rotation shows higher tensile strength, yield strength and percentage of elongation in compare to 1500 rpm rotaton speed. In addition, its tensile strength is about 5 % lower than Base Material (BM) which its ductility decreases up to 30 %.
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Wang, Yan. "Study on Behavior of CO2 Gas Shielded Welding Joint of Ultrafine Grain Steel." Journal of Physics: Conference Series 2393, no. 1 (December 1, 2022): 012008. http://dx.doi.org/10.1088/1742-6596/2393/1/012008.
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Abstract This research paper mainly studied the microstructure and hardness of the weld bead and welding heat affected zone of ultrafine grain steel after CO2 gas-shielded welding. After normalizing and quenching heat treatment, the changes in microstructure and hardness of welded joints were studied. These experimental results showed that the microstructure of the weld bead of the welded joint was dendritic. The microstructure of weld bead was a mixed structure of proeutectoid ferrite, side plate ferrite, bainite, and pearlite. The microstructure of the overheated zone of HAZ under the as-welded condition was ferrite and pearlite with coarse grains, and the normalized zone was pearlite and ferrite with smaller grains than that of base metal. The microstructure of the normalized + quenched welded joint was a mixture of low carbon martensite, pearlite and ferrite, and the ferrite content was less. The hardness change of these welded joints was that the welded joint hardness after normalizing + quenching was significantly higher than that of welded joints before heat treatment.
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Saggu, Mustansar Hayat, Nadeem Ahmed Sheikh, Usama Muhammad Niazi, Muhammad Irfan, and Adam Glowacz. "Predicting the Structural Reliability of LNG Processing Plate-Fin Heat Exchanger for Energy Conservation." Energies 13, no. 9 (May 1, 2020): 2175. http://dx.doi.org/10.3390/en13092175.
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Liquefied natural gas (LNG) is one of the hydrocarbon fuels with the least carbon footprint having a rapidly rising global share in the prime energy market. LNG processing for transportation at longer distances works under cryogenic conditions, especially when used for liquefaction and gasification applications. The supply chain of the eco-environmental friendly hydrocarbon is heavily dependent on the processing plant used for liquefaction and subsequent re-gasification of the natural gas. Plate-fin heat exchangers are extensively used in the LNG industry for both re-gasification as well as liquefaction processes. The exchange of heat during the process of natural gas phase change involves plate-fin heat exchangers working under cryogenic low-temperature conditions. The heat exchangers are designed to have brazed joints that are most vulnerable to failure under these temperature conditions. One failure of such a joint can not only hinder the supply chain but also may result in fire and life hazards. In almost all earlier studies, analytical and numerical methods were used to analyze these braze joints using finite element method methods and examining the stresses while keeping them at or near to ambient conditions. In this research, the plate-fin heat exchanger is investigated for its structural stability of brazed fins for three different fin configurations: plain, wavy and compound having different joint geometries. In addition, the analyses are carried out using experimentally measured brazed joint strength which is measured to be on average 22% lower than the base material strength owing to brazing process and resultant heat-affected zone (HAZ). Therefore, the reliability is assessed for these joints in terms of factor of safety (FOS) while keeping in view the actual yield criteria. It was found that the structural stability of compound fins configuration is weakest amongst all considered fin configurations. The failure of the compound fin brazed joint is expected to be along the horizontal path of the joint due to yielding. The study also predicts the life of the fin brazed joints in different joining directions with different topologies of fins commonly recommended in the literature. It is observed that the commonly recommended safe fin geometries are predicted to be susceptible to failure if a reduction in the brazed joint is considered. The analysis and recommendation in this paper shall provide a reliable and safe design approach for plate-fin exchangers for different operating conditions especially in low to cryogenic temperature applications.
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Zhao, Li-Hui, Da-Ang Li, Shuo Weng, and Song-Lin Zheng. "Static and fatigue performance of overlap welded thin plates." Materials Express 10, no. 4 (April 1, 2020): 461–68. http://dx.doi.org/10.1166/mex.2020.1657.
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Thin-plate overlap welding is an important connection method for the automobile chassis structure. The fatigue performance of the chassis structural components depends mostly on the welded joints. A detailed understanding of its performance plays an important guiding role in the design of the chassis structure. This study was aimed at investigating the performance of thin-plate overlap welded structures using the static tensile test and fatigue test. The general rule of the influence of base metal thickness on the static strength and fatigue performance of welded joints was also summarized. The failure mode of the welded joint and the crack propagation mechanism were discussed in terms of fracture morphology. The findings might lay a foundation for the anti-fatigue design and lightweight design of the chassis welded structures.
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Bredell, Marius, Klaus Grätz, Joachim Obwegeser, and AstridKruse Gujer. "Management of the Temporomandibular Joint after Ablative Surgery." Craniomaxillofacial Trauma & Reconstruction 7, no. 4 (December 2014): 271–79. http://dx.doi.org/10.1055/s-0034-1378181.
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Management of the temporomandibular joint in ablative head and neck surgery is controversial with no standardized approach. The aim of the study was to establish risk-based guidelines for the management of the temporomandibular joint after ablative surgery.Analysis of all patients’ records receiving ablative surgery involving the temporomandibular joint in the Department of Cranio-Maxillofacial and Oral Surgery, University Hospital of Zϼrich, from 2001 to 2012, was performed, identifying 15 patients and 14 reconstructive procedures. A literature search was done identifying all relevant literature on current approaches. Applicable cohorts were constructed, and relevant risks were extrapolated. Evaluated studies are not uniform in their reporting with nonhomogeneous patient groups. A diverse approach is used in the management of these patients with complications such as infection, ankylosis, limited mouth opening, plate penetration in the skull base, and plate loosening. Risk factors for complications appear to be radiation, costochondral graft, disk loss, and plate use alone. Clinical data suggest use of a plate with metal condyle reconstructions and previous radiation therapy as potential risks factors. Employing literature evidence and cumulated clinical data, a risk-based flowchart was developed to assist surgical decision making. Risk factors such as radiation, disk preservation, and soft tissue conditions are important complication-associated factors when planning surgery. Free vascularized fibula grafts appear to have the least complications that must be weighed against donor site morbidity.
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Qi, Jia Rui, Xu Ren Huang, Hai Xia Sun, and Yan Li Li. "Research on the Laser Welding Technology of LF21." Advanced Materials Research 941-944 (June 2014): 2012–15. http://dx.doi.org/10.4028/www.scientific.net/amr.941-944.2012.
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Traditional welding methods are difficult to adapt to the development of welding technology of aluminum alloys. Laser welding plays an important role in this field increasingly for its advantages. In this investigation, LF21 plate with a thickness of 2mm was welded utilizing the pulsed laser welding and the mechanical properties of the laser welded joints are analyzed. The tensile strength of welded joint is in the range of 196 Mpa to 232 Mpa. The maximum tensile strength is obtained at the working current of 250 A, pulse width of 6 ms and pulse frequency of 2 Hz. The maximum tensile strength can reach 87% of base material. The intensity factor of welded joint is in the range of 74% to 87%. The welded joint can meet the requirements of users.
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Fu, Li, and Fenjun Liu. "Innovate Method for Friction Stir Welding of Al-Mg-Si Alloy Thin Plate." MATEC Web of Conferences 269 (2019): 02006. http://dx.doi.org/10.1051/matecconf/201926902006.
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Al-Mg-Si (6061-T6) alloy with 0.8 mm thick plate was welded successfully by use of high speed friction stir welding (FSW) technology. The microstructural characteristics and mechanical property of the butt joints prepared by high speed FSW were analyzed in detail, the influence of welding parameters, fixture condition and after welding heat treatment were also explored. The results shown that sound surface topography and defect-free bonding interface were observed in the nugget zone (NZ). The microhardness of the as-welded joint was lower than that of the base metal because of the welding heat effect. Compared with the conventional speed FSW, the number of β-Mg2Si, Al2CuMg and Al8Fe2Si precipitated phases existed in the high speed FSWed NZ increased, which made the microhardness in the NZ improved significantly. The rod-shaped precipitates (Mg2Si) have the greatest influence on the microhardness distributions. The maximum tensile strength of 301.8 MPa, which was 85.8% of the base metal, was obtained at high rotation speed of 8000 rpm and fast welding speed of 1500 mm/min. The tensile strength of the ultra-high speed FSWed butt joints were improved significantly by post-weld artificial aging, with a maximum joint efficiency of 90.4%.
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Abe, Y., Takehiko Watanabe, H. Tanabe, and K. Kagiya. "Dissimilar Metal Joining of Magnesium Alloy to Steel by FSW." Advanced Materials Research 15-17 (February 2006): 393–97. http://dx.doi.org/10.4028/www.scientific.net/amr.15-17.393.
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Authors tried to butt-weld a mild steel plate to a magnesium alloy plate by the solid state welding using a rotating pin. This study investigated the effects of a pin rotating speed, the position for the pin axis to be plunged (pin offset) on the strength and the microstructure of the joint. The main results obtained are as follows. Butt-welding of a steel plate to a magnesium alloy plate was easily and successfully achieved. The maximum tensile strength of a joint reached about 70% of the magnesium base metal tensile strength and the fracture path was along the joint interface. When a pin rotating speed was slow, some defects appeared in the magnesium matrix due to the insufficient plasticization of the magnesium. The joint strength increased with the pin rotating speed. This seems to be because the plasticization of the magnesium was increased and the pressure for pushing the plasticized magnesium onto an activated faying surface of the steel increased. However, the excessive increase of the pin rotating speed caused the ignition of the magnesium, resulting in the decrease of a joint strength. At the pin offset of 0.1mm toward steel, steel fragments scattered in the magnesium matrix in the form of a small piece that had no influence to the joint strength. By contrast, larger offsets over 0.2mm produced the steel fragment continuous and parallel to the weld interface in the magnesium matrix, and the joint strength decreased.
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Zhang, Shu Guo, Yu Hua Chen, and Jun Hua Cui. "Microstructure and Mechanical Properties of Laser Welding Joint of Inconel 718 Super Thin Sheet." Advanced Materials Research 391-392 (December 2011): 479–83. http://dx.doi.org/10.4028/www.scientific.net/amr.391-392.479.
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Nd-YAG laser welding characteristics of Inconel 718, microstructures,tensile properties,and hardness of welding joint were researched. Nd-YAG laser welding was carried out on super thin Inconel 718 sheet(0.2 mm thick) with 6 specimens. The welding parameters of these specimens are varied expect for the welding speed(0.3mm/s), gas-flow rate (5L/min) and clearance between focal point and (plate) surface(0).In this research,the tensile strength of welding joint was found to be inferior to base metal and the ductility of welds was considerably lower than base material,the microhardness in weld zone is higher than the base material hardness and the hardness is highest in center zone of welding joint. These conclusions will be in favour of the manufacture with super thin Inconel 718.
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Waryasz, Gregory R., Stephen Marcaccio, and Joseph A. Gil. "Technique Tip." Foot & Ankle Specialist 10, no. 2 (November 10, 2016): 149–51. http://dx.doi.org/10.1177/1938640016677812.
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Lisfranc injury fixation or arthrodesis typically involves the reduction and fixation of several tarsometatarsal joints with either screws or a plate and screw constructs. A successful fixation or arthrodesis of the Lisfranc joint requires proper screw placement from the medial cuneiform to the base of the second metatarsal. This is typically done free-hand; however, we describe use of an anterior cruciate ligament guide to help maintain reduction and assist with drill trajectory for more accurate screw or suture button construct placement. Levels of Evidence: Level V
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Hsu, Cheng Ho, and Ren Kae Shiue. "Brazing Inconel 600 Using the VZ-2150 Filler for Plate Heat Exchanger." Key Engineering Materials 732 (March 2017): 1–4. http://dx.doi.org/10.4028/www.scientific.net/kem.732.1.
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The purpose of this investigation is focused on brazing Inconel 600 alloy using the nickel-based VZ-2150 filler foil for advanced plate heat exchanger application. Based on SEM microstructural observations and WDS chemical analysis results, both the amount and shape of precipitates in the brazed joint are changed with brazing parameters. With increasing the brazing temperature and/or time results in depletion of the boron from the joint into the grain boundary of base metal. The amount of boride in the joint is greatly decreased, and continuous grain boundary boride will dominate the entire brazed joint. However, the continuous grain boundary boride cannot be completely eliminated by increasing the brazing temperature and/or time.
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Chiocca, Andrea, Francesco Frendo, and Leonardo Bertini. "Evaluation of residual stresses in a tube-to-plate welded joint." MATEC Web of Conferences 300 (2019): 19005. http://dx.doi.org/10.1051/matecconf/201930019005.
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A deep understanding of the manufacturing process is needed in order to achieve safety and quality requirements for parts and components; to this regard, residual stresses play an important role in welded structures. Residual stresses are mainly caused by the extremely severe thermal cycle to which the welded metal and base material are subjected to during welding process and their knowledge leads to a better static and fatigue assessment of welded joints. This work deals with the study of residual stresses for a tube to plate T-joint, made of S355JR carbon steel. The work was carried out by both numerical simulations and experimental tests. The numerical simulations were performed by Ansys FE code through a structural-thermal full transient analysis to evaluate stress, strain and temperature in each node at each step of the simulation. The “birth and death” method was employed, together with temperature-dependent material properties.A2Danda3D simulation were performed, in order to evaluate possible differences due to the welding process. Numerical results were compared to some preliminary measurements obtained through an incremental cut made on the plate.
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Lee, S. W. J., Z. Y. Ng, and Q. A. Fogg. "Three-dimensional analysis of the palmar plate and collateral ligaments at the proximal interphalangeal joint." Journal of Hand Surgery (European Volume) 39, no. 4 (June 5, 2013): 391–97. http://dx.doi.org/10.1177/1753193413492288.
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The purpose of this study was to analyze the palmar plate complex at the proximal interphalangeal joint using a three-dimensional (3D) technique, which makes it easier to understand the dimensions of structures and their relationship to the adjacent components. This method allows individual elements to be removed virtually, facilitating clearer observation of each component. Sixteen cadaveric specimens were dissected and reconstructed in a 3D virtual environment. The palmar plate is made up of a distal, fibrous portion and a proximal, membranous portion, which anchors distally on the base of the middle phalanx and is continuous with the bilateral check-rein ligaments proximally. The accessory collateral ligaments and the A3 pulley suspend the palmar plate laterally.
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Xie, Qiao Yun, and Xiang Ling. "Numerical Investigation on the Effect of Copper Filler Thickness on the Brazed Residual Stress." Advanced Materials Research 79-82 (August 2009): 1161–63. http://dx.doi.org/10.4028/www.scientific.net/amr.79-82.1161.
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In this study, the residual stress in copper base brazed stainless steel plate-fin structure was investigated through thermo-mechanical coupled finite element analysis (FEA) models. The results show that the maximum residual tensile stress occurs in the brazed joint next to the plate side. In addition, the dependence of residual stress distribution on filler thickness was also analyzed. The detailed stress distribution would provide some constructive instructions in the practical brazing procedure.
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Luo, Chuan Hong, Ting Chen, and Wei Ping Peng. "Research on Joint Strength of Aluminum Alloy Welded by FSW." Applied Mechanics and Materials 590 (June 2014): 249–53. http://dx.doi.org/10.4028/www.scientific.net/amm.590.249.
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The joint of 2219-T6 aluminum alloy plate was obtained by friction stir welding, and the microstructures and mechanical properties of the joint were investigated. The causes of the weakened joint strength in friction stir welding were analyzed and summarized correspondingly. The tensile properties show that the transverse tensile strength of the joint can reach about 70% of the base metal and the elongation can reach about 7%. The main reason of the weakened strength is due to the plastic damage of metal, followed by the defects generated in the nugget zone and the growth of θ phase in the heat affected zone.
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Liu, Bangyi, Yang Zhou, Linhao Gu, Dalin Wang, and Xiaoming Huang. "Mechanical Behavior of Concrete Pavement considering Void beneath Slabs and Joints LTE." Advances in Civil Engineering 2020 (November 23, 2020): 1–13. http://dx.doi.org/10.1155/2020/8826301.
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Dowel bars are arranged between two slabs of jointed plain concrete pavements to transfer load between them. The looseness of these dowel bars leads to the decrease of the load transfer efficiency (LTE). Meanwhile, repeated vehicle load can result in void near the joints. In this paper, the behaviors of concrete pavement under the effect of void size and joint stiffness were studied by using ABAQUS software. The FEA model was calibrated for different element parameters based on mesh convergence analysis and validated by comparison with previous studies. The voids beneath slabs were considered in this study, including the loaded slab and unloaded slab. The different effects of base course modulus on the stress of loaded slab are also analysed. It is concluded that the results show that the void size and joint stiffness affect the stress of the loaded plate. Smaller void size and larger joint stiffness will lead to the maximum stress located at the bottom of the loaded slab, and the void size has little effect on the stress of the loaded slab. Otherwise, the larger void size will cause larger stress. The effect of base modulus on stress is similar.
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Carek, Andreja, Jasenka Zivko Babic, Zdravko Schauperl, and Tomislav Badel. "Mechanical Properties of Co-Cr Alloys for Metal Base Framework." International Journal of Prosthodontics and Restorative Dentistry 1, no. 1 (2011): 13–19. http://dx.doi.org/10.5005/jp-journals-10019-1003.
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ABSTRACT Purpose This study investigated the effect of two welding methods on the mechanical properties of a cobalt-chromium (Co-Cr) alloy for metal base framework. Materials and methods Fifty-four plates were cast for TIG and laser welding. Cobalt-chromium for plates were prepared and divided into three groups of 18 samples. Group 1 and 2 were cut at the center of the plate. Eighteen specimens were joint by using TIG (Primotec Phaser Mx1), and other 18 by laser (Nd:YAG laser). Specimens in the as-cast condition were used as control group (group 3). After joining, each specimen was microscopic analyzed and tested to flexural and dynamic failure. Failure loads were recorded and fracture strength calculated. Results The changes in microstructure and micro-hardness were studied in the heat-affected zones (HAZ) and unaffected zones. Micro- hardness values increased in the heat-affected zone (HAZ) and in welded material compared to the parent material. The ANOVA test showed a highly significant difference (α = 0.05) between the joint strengths of the as-cast control specimens and, TIG and laser-welded joints. The flexural and dynamic strength of the joints were higher than those for the TIG-welded joints, and both were higher than the laser-welded joint strengths for the tested Co-Cr alloy. Conclusions Although laser is more popular, in our research TIG showed better results for flexural and dynamic strength.
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Asif, Umar, and Javaid Iqbal. "Modeling, Simulation and Motion Cues Visualization of a Six-DOF Motion Platform for Micro-Manipulations." International Journal of Intelligent Mechatronics and Robotics 1, no. 3 (July 2011): 1–17. http://dx.doi.org/10.4018/ijimr.2011070101.
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This paper examines the problem of realizing a 6-DOF motion platform by proposing a closed loop kinematic architecture that benefits from an anthropological serial manipulator design. In contrast to standard motion platforms based on linear actuators, a mechanism with actuator design inspired from anthropological kinematic structure offers a relatively larger motion envelope and higher dexterity making it a viable motion platform for micromanipulations. The design consists of a motion plate connected through only revolute hinges for the passive joints, and three legs located at the base as the active elements. In this hybrid kinematic structure, each leg is connected to the top (motion) plate through three revolute hinges and to the bottom (fixed) plate through a single revolute joint forming a closed-loop kinematic chain. The paper describes the mathematical modeling of the proposed design and demonstrates its simulation model using SimMechanics and xPC Target for real-time simulations and visualization of the motion cues.
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Zhang, Hao, Shujin Chen, Yuye Zhang, Xinyi Chen, Zhipeng Li, and Zhidong Yang. "Effect of High Rotational-Speed Friction-Stir Welding on Microstructure and Properties of Welded Joints of 6061-T6 Al Alloy Ultrathin Plate." Materials 14, no. 20 (October 12, 2021): 6012. http://dx.doi.org/10.3390/ma14206012.
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The butt joint of an Al alloy ultrathin plate with a thickness of 0.5 mm is realized by a high rotational-speed friction-stir welding process. It overcomes the welding difficulty that the ultrathin plate is often torn, and it cannot be formed by conventional friction-stir welding. The results show that the weld surface is well-formed at a high-rotational speed (more than 8000 rpm), and there are no obvious defects in each area of the joint section. The nugget zone (NZ) is a recovery recrystallization structure dominated by large-angle grain boundaries, with a grain size of about 4.9 μm. During grain growth, the texture is randomly and uniformly distributed, and the strength is balanced. The microhardness of the NZ increases significantly with the increase in rotational speed, and the fluctuation range of hardness value is small. The NZ β–Mg2Si is finer and significantly less than the base metal (BM). The heat dissipation of the thin plate is fast, so a Cu plate is used as the backing plate to slow down the steep temperature-drop process in the weld area. Compared with a low rotational speed, the precipitation amount of brittle phase Al–Cu–Mg–Cr and Al–Fe–Si–Mn is significantly reduced, which is conducive to improving the mechanical properties of the joint. At a high rotational speed, 12,000 rpm, the best tensile strength of the joint is 220 MPa, which is about 76% of the BM (290 MPa), and the highest elongation is 9.3%, which is about 77.5% of the BM (12%). The fracture mode of the joint is a typical plastic fracture.
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Shinozaki, K., and K. Koyama. "Development of Al/Cu Dissimilar Brazing Joint Controlled Form of Intermetallic Compound." Materials Science Forum 539-543 (March 2007): 4075–80. http://dx.doi.org/10.4028/www.scientific.net/msf.539-543.4075.
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Brazing of Al to Cu using Al-Si-Mg-Bi brazing alloy has been carried out in a vacuum furnace. In the brazed interlayer, there were two kinds of intermetallic compounds. One of these intermetallic compounds was θ phase and the other was δ(Cu3Al2). Tensile strength of the joint was only about 15MPa. Deformation behavior of Al/Cu brazing joint was brittle without deformation of the base metal. The specimen was fractured in the intermetallic compound which was mainly θ phase. In order to improve the tensile strength of Al/Cu dissimilar joint, Cu cladding Ag (thickness: 0.1mm) substituted for Cu. As the result, tensile strength of the joint was about 70MPa and the specimen was fractured in an Al base metal. In this joint, plate-like intermetallic compound, δ (Ag2Al) was formed in the brazed interlayer. The shape of δ(Ag2Al) was quite different from θ phase found in Al/Cu joint. It was considered that the shape of reaction layer remarkably affected to the strength of the Al/Ag-Cu clad dissimilar joint.
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Nikulin, Ilya, Alla Kipelova, Sergey Malopheyev, and Rustam Kaibyshev. "Synergetic Effect of ECAP and Friction Stir Welding on Microstructure and Mechanical Properties of Aluminium Sheets." Materials Science Forum 667-669 (December 2010): 505–10. http://dx.doi.org/10.4028/www.scientific.net/msf.667-669.505.
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Friction stir welding (FSW) was used to join the submicrocrystalline (SMC) grained Al-Cu-Mg-Ag sheets produced by equal channel angular pressing (ECAP) followed by hot rolling (HR). The effect of SPD and FSW on the microstructure and mechanical properties in the zone of base metal, as well as in the stirred zone (SZ) were examined. In addition, effect of standard heat treatment on microstructure and mechanical properties in these zones was considered. A refined microstructure with an average grain size of ~ 0.6 m and a portion of high-angle grain boundaries (HAGBs) of ~0.67 was produced in sheets by ECAP followed by HR at 250°C. The microcrystalline grained structure with average grain size of ~2.3 mm was found in joint weld. The moderate mechanical properties were revealed in SMC sheets and joint welds. Heat treatment considerably increases strength of the base metal as well as the joint welds. The higher strength of the alloy after T6 temper is attributed to the dense precipitations of dispersoids having plate-like shape which are uniformly distributed within aluminum matrix. It was observed that FSW can produce full strength weld both in the tempered and in the un-tempered conditions.
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Kim, Seong-Kyum, Jong-Kwon Park, Sang-Hee Han, Byung-Cheol Kim, and Il-Young Jang. "A Study on Punching Shear of Column-Foundation Joint Connection for Reinforced Steel Base Plate." Journal of the Korea institute for structural maintenance and inspection 19, no. 2 (March 30, 2015): 1–9. http://dx.doi.org/10.11112/jksmi.2015.19.2.001.
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BABU, K. KAMAL, K. PANNEERSELVAM, P. SATHIYA, A. NOORUL HAQ, S. SUNDARRAJAN, P. MASTANAIAH, and C. V. SRINIVASA MURTHY. "EXPERIMENTAL INVESTIGATION ON FRICTION STIR WELDING OF CRYOROLLED AA2219 ALUMINUM ALLOY JOINTS." Surface Review and Letters 24, no. 01 (December 22, 2016): 1750001. http://dx.doi.org/10.1142/s0218625x17500019.
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In this paper, experimental investigation on cryorolled aluminum AA2219-T87 plate by using friction stir welding (FSW) process is carried out. AA2219-T87 plates with a size of 200[Formula: see text]100[Formula: see text]22.4 mm were rolled and reduced to 12.2[Formula: see text]mm thickness (more than 45% of reduction in total thickness of the base material) at cryogenic temperature (operating temperature range [Formula: see text]90–[Formula: see text]30[Formula: see text]C). The cryorolled (CR) plates have reduced grain size, improved hardness and increased corrosion resistance property compared with the uncryorolled AA2219-T87 plates. FSW joints of cryorolled AA2219-T87 plates were prepared using cylindrical threaded FSW tool pin profile. Mechanical and metallurgical behaviors of friction stir welded joints were analyzed and the effects of the FSW process parameters are discussed in this paper. The variation of microhardness in the FSW joint regions were correlated with the microstructure of FSW joints. Cryorolled plate and FSW joints were tested for corrosion resistance using potentiodynamic polarization test. FSW joints shows better result during the corrosion resistance analysis compared to base AA2219-T87. The X-ray diffraction (XRD) test results showed that fine [Formula: see text]-Al grains with eutectic phase (Al2Cu) were present in the weld nugget (WN). The large clusters of strengthening precipitates were reduced in size and merged with the weld nugget portion.
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Xu, Wei Feng, Jin He Liu, Dao Lun Chen, Guo Hong Luan, and Jun Shan Yao. "Tensile Properties and Strain Hardening Behavior of a Friction Stir Welded AA2219 Al Alloy." Advanced Materials Research 291-294 (July 2011): 833–40. http://dx.doi.org/10.4028/www.scientific.net/amr.291-294.833.
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Microstructures, tensile properties and work hardening behavior of friction stir welded (FSWed) AA2219-T62 aluminum alloy (in its one-third bottom slice of a 20 mm thick plate) were evaluated at different strain rates. While the yield strength was lower in the FSWed joint than in the base metal, the ultimate tensile strength of the FSWed joint approached that of the base metal. In particular the FSW resulted in a significant improvement in the ductility of the alloy due to the prevention of premature failure caused by intergranular cracking along the second-phase boundary related to the presence of the network-like grain boundary phase in the base metal. While stage III and IV hardening occurred after yielding in both base metal and FSWed samples, the FSW led to stronger hardening capacity and higher strain hardening exponent and rate due to the enhanced dislocation storage capacity associated with the microstructural change after FSW. The fracture surface of the FSWed joint was mainly characterized by dimples and tearing ridges along with micropores.
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Wu, Chong, Guo Tao Yang, Zu Lin He, De Fu He, and Qing Tian Su. "Numerical Investigation and Structural Analysis on the Springing Joint of a Steel Truss Arch Bridge." Applied Mechanics and Materials 105-107 (September 2011): 1268–71. http://dx.doi.org/10.4028/www.scientific.net/amm.105-107.1268.
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Arch springing is an important critical joint in a steel truss arch bridge, and it has a great influence on the mechanical behavior of the global structure. The adoption of a reasonable structure of the springing joint is of important significance in the design of an arch bridge. In this paper, with regard to the structure of Xinshiji Bridge, two types of arch springing were put forward. In Scheme-1, the lower chords of steel truss arch ribs are connected to the concrete piers with shear studs on the ribs and cap plates welded on the ribs at the top of concrete piers., while Scheme-2 is a integrated spring joint with a base plate on the bottom of the steel arch ribs and with reinforcing bars through the holes on the joints steel arch ribs. 3D finite element models of the two types of springing joint were established and the relative slips between the concrete and steel were taken into account in the analyses. The mechanical behavior of the concrete and the steel structure of the joints under applied loads was investigated and the analysis result showed that Scheme-2 is a relative better structure of springing joint, with less principle tensile stress in concrete and less Mises stress in steel plates.
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Ohta, Akihiko, Naoyuki Suzuki, and Yoshio Maeda. "Fatigue Crack Propagation Properties of Welded Joints at 300°C." Journal of Pressure Vessel Technology 125, no. 2 (May 1, 2003): 131–35. http://dx.doi.org/10.1115/1.1563628.
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Fatigue crack propagation properties of welded joints were investigated on steel plate for boilers and other pressure vessels. The fatigue crack propagation properties at 300°C became similar to those at room temperature when the thermal stress could be reduced down to −1 MPa by using center cracked type specimen with longitudinal slits and a specially designed furnace. The tensile residual stress was +152 MPa in the as-welded joint, and +12 MPa after PWHT. The fatigue threshold was about 2.7, 5.1 and 7.3 MN/m3/2 for weld metal in the as-welded condition, after PWHT and the base metal, respectively.
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Mallieswaran, Kuppusamy, Shanmugam Rajasekaran, Mari Vinoth Kumar, and Chinnasamy Rajendran. "Steel shot peening effects on friction stir welded AA2014-T6 aluminum alloys." Materials Testing 64, no. 8 (August 1, 2022): 1202–13. http://dx.doi.org/10.1515/mt-2021-2173.
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Abstract The high-strength aluminum alloy is the potential candidate to replace conventional materials. It has excellent corrosion-resistant, recyclable machinability. The joining of such a type of alloy using fusion welding is very difficult. Solid-state welding, friction stir welding (FSW) has been used. However, this process has attained a maximum joint of 90% of base material strength. The drop of remaining strength is due to the formation of the temperate region in the thermo-mechanically affected area. Most of the researchers have been reported that the failure has observed at the interface. Many techniques have been followed to improve the strength at the temperate region, namely, post-weld heat treatment, backing plate change, sheet position, tool offset, etc. In this study, the shot blasting technique has been used to improve the lost strength in the soft region. From the experimental result, the joint shot-peened with steel shot yielded higher strength than the classical friction stir welded (C-FSW) joints. Moreover, the stability of the shot-peened joint has been conceived 6.9% more than the C-FSW joint.
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Subbaiah, K. "Tensile Properties and Microstructure of Friction Stir Welded Cast Al-Mg-Sc Aluminum Alloy." Applied Mechanics and Materials 852 (September 2016): 375–80. http://dx.doi.org/10.4028/www.scientific.net/amm.852.375.
Full textAbstract:
The mechanical behavior of Friction Stir (FS) welds made under the most favorable choice of parameters was determined using tensile tests and was correlated to the microstructures of the FS welded cast Al-Mg-Sc alloy plate and the base metal. FS Zones in the Cast Al-Mg-Sc specimens were much harder than the cast base metal. The global joint fractured in the base metal, and thus possessed greater tensile strength than the base metal. Component part joint samples with lesser gage length failed at the weld nugget. Microstructural evaluation of the alloy plates revealed that due to FS welding, fine and fragmented dynamically recrystallized grains have been formed in the weld nugget. The fine fragmented microstructure of the weld nugget was responsible for better tensile properties than the cast base metal. These results clearly show that FS welding is an optimum/suitable welding process for cast Al-Mg-Sc alloys.
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Tao, Wang, Wang Zhan, and Wang Junqi. "Experimental Study and Finite Element Analysis of Hysteretic Behavior of End-plate Connection Semi-Rigid Space Steel Frames." Open Civil Engineering Journal 7, no. 1 (July 12, 2013): 68–76. http://dx.doi.org/10.2174/1874149501307010068.
Full textAbstract:
To investigate the seismic behavior of end-plate connection semi-rigid space steel frames, three 1/4-scale specimens were tested under cyclic load. Finite element analysis which took initial geometric imperfections into consideration was also conducted, and the results conform to experimental results. The failure modes, hysteretic behavior, deformation capacity and energy-dissipation capacity of the end-plate connection semi-rigid space steel frame have been explicated in this paper. The investigation in this paper indicates that: (1) the end-plate connection semi-rigid space steel frames exhibit full hysteretic loops under horizontal cyclic load and have good ductility as well, indicating that this kind of frames can satisfy the deformation demand in strong earthquakes. (2) Plastic hinges formed at beam ends, and the stress and deformation amplitudes of joint-panels were smaller than those of column base and beam ends. It shows that this kind of frames satisfy the design principle “strong column weak beam, strong joint weak component”.