Browse Topic: Joining

Items (4,424)
The growing demand for lightweight, high-strength materials in marine and aerospace structures has promoted the use of friction stir welding (FSW) for welding dissimilar aluminum alloys. However, tensile residual stresses and microstructural heterogeneities often degrade weld integrity. This study investigates the combined impact of base material positioning, single- and double-pass FSW, and post-weld shot peening (SP) on the metallurgical and mechanical properties of AA6061–AA2017 joints. Five welding configurations were examined to evaluate how varying base material positions on the advancing and retreating sides affect material flow and mechanical behavior. Post-weld SP effectively presented compressive residual stresses, reduced surface defects, and refined surface grains. The average grain size in the stir zone was reduced from 5.2 μm (single-pass) to 2.0 μm (double-pass U-turn) after SP, confirming significant grain refinement through dynamic recrystallization. Mechanical testing
Nukathoti, Raja SekharBattina, N. Malleswara RaoVanthala, Varaha Siva PrasadChirala, Hari KrishnaMaloth, Balu
Tailor Welded Blanks are critical for automotive lightweighting yet prone to premature failure due to differential thickness and strength across the weld. This study utilized digital image correlation (DIC) to analyze the maximum in-plane principal Hencky strain (E₁max) and axial strain (εₐₓₐₗ) of TWBs under complex loading conditions, including biaxial and plane-strain states. Twelve distinct material stack-ups were tested to evaluate the impact of material difference on formability. Results indicated that differential properties significantly altered strain distribution, often forcing localization onto the thinner or softer sheet. While UHSS welds provided high load capacity with limited ductility, combinations using HSLA or IF substrates were susceptible to early localization and unstable fracture. Comparative heatmaps illustrate strain evolution across all samples, providing spatial insights beyond conventional force–displacement analysis. Metallurgical characterization confirmed a
Aminzadeh, AhmadSheng, ZiQiangHuang, LuMcCarty, EricBiro, Elliot
In the context of automotive lightweighting and efficient manufacturing, welding is a key joining method for aluminum body structures due to its maturity, versatility, and cost effectiveness. This study investigates MIG butt welding of AA6063-T6 sheets using a sequential thermo-mechanical finite element model with a double-ellipsoid heat source. Thermocouple histories and macroscopic metallography of the weld-pool morphology are used to validate the predicted temperature field, and post-weld deformation measured by a coordinate measuring machine is compared with the simulation to confirm overall model reliability. Hardness mapping across the joint partitions the material into weld metal (WM), heat-affected zone (HAZ), and base metal (BM). Miniature tensile specimens extracted along the weld provide local mechanical properties, from which linear strength–hardness relations are established. Building on these results, a five-material equivalent strength model covering WM, HAZ-I, HAZ-II
Shao, JiyongMeng, DejianXiang, YaoGao, Yunkai
This study presents an effective predictive methodology for determining the mechanical properties of glue-laminated motor cores, with explicit consideration of glue disposition, including bonding pattern, configuration, location, and coverage. In laminated stator cores, glue bonding and stacking processes jointly govern the mechanical integrity of the lamination stack. Practical production bonding schemes are typically nonuniform and localized, leading to spatial variations in stiffness and to locally anisotropic, orthotropic material behavior. These effects influence both the in-plane and through-thickness stiffness of the stator core. They can significantly affect the accuracy of structural simulations, such as NVH responses of high-speed traction motors and e-drive systems. Given the constituent material properties of the electrical steel laminations and the glue, this work distinguishes the governing mechanisms underlying the equivalent core properties. The in-plane stiffness is
Nie, Zifeng
Accurate detection and evaluation of kissing bonds in composite materials is essential to ensure the integrity of the component structure, but traditional NDT (non-destructive testing) methods struggle to identify imperfect bonds and zero-volume debonds. In this study, a vibration analysis method based on holography was applied to detect kissing bonds by monitoring the changes in natural frequencies of the same sample before and after fatigue loading. Both pristine and kissing bond samples were tested under identical conditions, and their vibration characteristics (natural frequency, amplitude, and mode shape) were measured using holography. The experimental results show for the intact sample exhibited no changes in natural frequency amplitude or mode shape after fatigue loading, confirming that the applied fatigue test did not affect the integrity of its adhesive layer. In contrast, for the sample with a kissing bond, after fatigue loading, the natural frequency decreased by up to 22
Gao, ZhongfangFang, SiyuanGerini-Romagnoli, MarcoYang, Lianxiang
This paper presents the multidisciplinary development of a hybrid automotive hood manufactured using double-shot injection molding with overmolded brackets. Conventional steel and aluminum hoods, while structurally reliable, pose challenges in terms of weight reduction, pedestrian head protection, and manufacturing cost. Composite and thermoplastic alternatives supported by computational analysis and advanced molding processes provide opportunities to address these challenges. Finite element analysis (FEA) was employed to evaluate torsional and bending stiffness, locking load, and crashworthiness, while pedestrian headform simulations following ECE R127 and EEVC WG17 guidelines were conducted to assess compliance with safety regulations. Adhesion and bonding strength of overmolded polymer–polymer interfaces were studied to validate manufacturing feasibility. Results confirm that hybrid hoods fabricated using multi-material double-shot molding can achieve weight reductions of up to 30
Ganesan, KarthikeyanSeok, Sang HoJo, Hyoung Han
Due to the spot weld and mechanical fastener share the similar characteristics to join sheets together with differences in deformation behavior around joint region, a novel spot joint element (user-defined element) consists of regular Mindlin shell elements and equations for different kinematic constraints is proposed to simplify the spot joint representation in lightweight automotive structures. The novel spot joint element can not only provide accurate deformation behavior around joint region but also output mesh-insensitive structural stresses at virtual nodes with the use of traction-based structural stress method for fatigue failure analysis. In this investigation, the structural stress distributions around joint circumference in the lap-shear specimens with spot weld or fastener are first calculated to validate the accuracy of the novel spot joint element. Then, the structural stresses along different cross-sections emanating from joint are also calculated for the specimens with
Wu, ShengjiaZhang, LunyuDong, Pingsha
The application of multiple materials in vehicle bodies is accelerating as the adoption of lightweight aluminum alloys and composite materials advances rapidly. These materials play a crucial role in reducing overall vehicle weight, enhancing fuel efficiency, and complying with increasingly strict environmental regulations. As the automotive industry continues to evolve toward electrification and sustainability, the integration of lightweight and high-performance materials has become a key design strategy. However, the use of multiple materials creates new challenges in manufacturing, particularly for joining technologies. Since different materials have varying mechanical properties, thermal behavior, and surface characteristics, the selection of appropriate joining methods is essential for ensuring structural integrity and durability. Depending on material types, thicknesses, production processes, and cost constraints, various joining techniques—such as mechanical fastening, welding
Takuno, SougoIsono, ToshiyukiUrakawa, KazushiGoto, SuguruKawamura, HiroakiNiisato, EitaIshigami, Yuta
This work presents two approaches for weld optimization aimed at reducing manufacturing cost and process time, while meeting structural performance requirements in automotive structures. The first approach uses topology optimization to identify the most efficient weld layouts. A design space is generated along mating flanges, joints, and panel interfaces, where potential weld locations are defined. Welds are treated as discrete design variables, and the topology optimization systematically evaluates their contribution to global stiffness and load path integrity. Non-critical welds, those with minimal impact on stiffness, durability, or crashworthiness, are eliminated, resulting in a minimized weld pattern that maintains structural performance. The second approach applies Multi-Disciplinary Optimization (MDO) to balance weld reduction with performance targets across multiple domains, including linear and non-linear stiffness, crashworthiness, and fatigue. Using a preprocessing tool
Koppaka, VinayaYoo, Dong YeonChavare, Sudeep
The present study investigates optimization of ultimate tensile strength (UTS) in FSW of AA2024-T3 and SS304 in a butt joint configuration. An L18 mixed-level orthogonal array was used to design 18 experiments, varying tool rotational speed (450, 560, and 710 rpm), traverse speed (20, 25, and 40 mm/min), and pin offset (1 and 1.5 mm toward the Al side). The tool rotational speed had the greatest influence on UTS, contributing nearly one-third of the total variance, followed by pin offset and traverse speed. The optimal combination, 450 rpm, 20 mm/min, 1.5 mm offset, yielded a UTS of 344.7 MPa and a joint efficiency of 78.3%. At this setting, peak temperatures reached ~356 °C, ensuring sufficient plasticization and uniform mixing of the Al–SS interface, producing a refined stir zone with an average grain size of 4.2 μm. Fracture analysis revealed ductile failure at the optimal parameters, whereas suboptimal conditions resulted in brittle or mixed fractures due to either insufficient or
Mir, Fayaz AhmadKhan, Noor ZamanPali, Harveer Singh
This research investigates the alterations in microstructure, microhardness, and joint strength resulting from the dissimilar friction stir welding (FSW) of WE43 magnesium alloy to AA7075 aluminium alloy. The study specifically analyses the role of FSW process parameters in the formation of intermetallic compounds (IMCs), the evolution of grain structure, the resultant microhardness distribution across the weld zone, and the joint tensile strength. A comprehensive microstructural characterization was performed utilizing optical microscopy (OM), field emission scanning electron microscopy with energy-dispersive X-ray spectroscopy (FESEM-EDS), electron backscatter diffraction (EBSD), and X-ray diffraction (XRD). These analyses confirmed significant grain refinement in the stir zone and the identification of various IMCs at the weld interface. Microhardness mapping indicated a gradient profile, with the weld nugget exhibiting superior hardness attributed to its dynamically recrystallized
Ahmad, TariqKhan, Noor ZamanAhmad, BabarSiddiquee, Arshad Noor
Topology optimization (TO) has become a reliable and lightweight design approach which was widely adopted in multiple industrial applications. Over the past decades, TO has advanced through three major development stages to increase its practicality and application scope: single-material topology optimization (SMTO), multi-material topology optimization (MMTO), and multi-joint topology optimization (MJTO). SMTO involves only one candidate material, whereas MMTO takes multiple candidate materials into consideration, which widen the application scope of TO. In terms of MJTO, it not only considers multiple candidate materials but also considers the bonding material between dissimilar candidate materials, improving practicality over MMTO. However, prior MJTO methods overlook the geometry of dissimilar material interfaces, a factor that may impact material bonding effect. In this paper, a novel MJTO algorithm is introduced to enable explicit control over interface geometry in MJTO. Central
Shi, YifanHuang, YuhaoKim, Il Yong
A computational study based on a conjugate heat transfer (CHT) method in SimericsMP+ was performed to predict the winding temperatures in an X76 emotor. In this study, the thermal load was represented in the simulation through the solution of electromagnetic equations in SimericsMP+, where heat generation was driven by root-mean-square (RMS) current, while liquid cooling was applied at flow rates ranging from 1 LPM to 6 LPM. Simulations were conducted to measure the temperature on three thermocouple locations on each side of the winding crown and weld regions under steady operation. The computational strategy employed a loosely coupled approach. A fluid-only simulation was first carried out to establish stable flow conditions, followed by coupling with solid conduction where the winding acted as the heat source. The predicted temperature distributions were then compared with test data. Results obtained show good agreement, with differences remaining within an acceptable range, thereby
Jia, KunSchlautman, JeffSrinivasan, Chiranth
For centuries, steel has been a cornerstone material for structural construction; by contrast, adhesive joining is a relatively nascent technology, particularly in heavy structural applications. The present article aims to provide the reader a review of the applications of adhesive joining in steel-based applications. Steel being a popular material in many industries due to its excellent mechanical properties, but traditional joining methods might have certain limitations viz. ability to withstand vibrations or movement, distortion, difficult to repair, and the like. Adhesive joining provides an alternative approach that offers advantages like reduced weight, improved corrosion resistance, enhanced aesthetics, ability to join multi-materials, ability to resist vibrations to a certain limit, and the like. This article examines the use of steel within the automotive and construction industries, intentionally narrowing its scope from steel’s broader range of applications. This article
S., ShrrayArora, Kanwer Singh
This specification covers an aluminum alloy in the form of wire, sheet, foil, pig, grains, shot, and chips (see 8.6).
AMS D Nonferrous Alloys Committee
The increasing demand for quiet and efficient electric vehicles has highlighted the importance of understanding vibration and noise characteristics of motor stators. Previous studies have extensively modeled electromagnetic excitation and laminated structures, but there has been little experimental evidence clarifying how different interlaminate fastening methods affect vibration modes under comparable conditions. This knowledge gap limits the ability to optimize fastening strategies for noise and vibration control in practical motor design. In this study, laminated stator cores were fabricated with different fastening conditions—bolting, clinching, and welding—and subjected to vibration testing and experimental modal analysis. Natural frequencies, damping ratios, and mode shapes were identified for torsional, circumferential, and breathing modes. The results revealed that the in-plane torsional natural frequencies increase with bolt axial force, while clinching provides additional
Matsubara, MasamiSaito, AkiraShimada, ShogoOishi, TaizanFuruya, KoheiKawamura, ShozoTajiri, Daiki
Between the 1920s and 1930s, aluminum started replacing wood as the primary material in aircraft construction and soon became the backbone of modern aviation. Its popularity stemmed from a combination of properties, high strength-to-weight ratio, corrosion resistance, and ease of forming that made it ideal for demanding aerospace applications. Throughout much of the 20th century, high-strength aluminum alloys dominated aircraft design, accounting for 70-80 percent of commercial airframes and more than half of many military aircraft. Even after the introduction of fiber-polymer composites in the early 2000s, aluminum has remained a critical material because it continues to offer the strength, lightness, and versatility needed for modern aviation. Industry forecasts predict that commercial air travel will double in the next 25 years, which means more pollution will be released into the atmosphere. One way to help reduce these emissions is by building airplane fuselages and wings with
Carbon fiber-reinforced polymers (CFRPs) have become essential in modern aerospace structures, from fuselage skins and wing components to nacelles, interior structures, and a growing range of primary load-bearing parts. Their high strength-to-weight ratio delivers major benefits in fuel efficiency, payload capacity, and fatigue performance. Yet achieving reliable adhesive bonds on CFRP surfaces remains a persistent engineering challenge. The low intrinsic surface energy of composites - particularly under thermal cycling, vibration, and moisture exposure - limits bond durability unless surfaces are properly prepared. Plasma surface treatment has emerged as a pivotal solution, offering a fast, controllable, and non-destructive way to increase surface energy, improve wettability, and enhance adhesion across complex geometries. This is especially important as the aerospace industry transitions from thermoset to thermoplastic composites (TPCs), which enable faster processing, lower
This paper presents a comprehensive numerical methodology for simulating the coupled process-structure behavior of short glass fiber-reinforced, injection-molded thermoplastics. The approach integrates elastoplastic and anisotropic material characteristics using three engineering tools: Moldflow, Digimat, and ABAQUS. It accounts for fiber orientation and injection molding defects, linking to thermo-mechanical performance. This method enables accurate virtual modeling of real-time injection-molded components by transferring anisotropic data from Moldflow to ABAQUS. In this study, short fiber orientation and potential injection molding defects such as weld lines and residual stresses are discussed using Moldflow simulation. Besides, Digimat is employed as an interface tool to facilitate the transfer of Moldflow simulation results, namely fiber orientation and material behavior in the allied configurations directly into ABAQUS. This integration enables the evaluation of thermo-mechanical
T, KalingaYanamadala, Dharma TejaMattupalli, VenkataChirravuri, BhaskaraMiller, Ronald
Welding simulations are transforming industrial manufacturing by enabling a predictive and first-time-right approach for process development. Advanced techniques such as Finite Element Analysis (FEA) help in accurate prediction of temperature distribution, residual stress, distortions and potential defects prior to physical welding which in turn support for addressing key challenges associated with Heat Affected Zones (HAZ) like distortion, fitment issues and post-weld cracking. Early integration of simulation in the development cycle significantly reduces lead time, enhances durability, and improves manufacturing efficiency. This study presents a simulation-based product development approach to mitigate post-weld crack generation issues in a complex multiple weld configuration of an automotive sheet metal assembly. The methodology adopts a two-stage framework: first, identifying the root cause of crack generating through baseline weld simulation; and second, implementing design
Nalawade, RahulDeshmukh, Kishor PandurangVidhate, DigambarPrakash, VedDabhadkar, Mandar Mukund
The tailgate, as the rearmost vehicle opening, plays a pivotal role in defining the rear aesthetic theme while ensuring structural durability and maximizing luggage space. Contemporary automotive design trends highlight an increasing demand for Full width tailgate-mounted tail lamp configurations, which deliver a bold and dynamic visual appeal. Enhanced by animated lighting features, these designs cater to the preferences of Gen Z customers, becoming a decisive factor in purchasing decisions. However, integrating these complex tail lamp structures introduces significant engineering challenges, including increased X-dimension lamp volume, thereby providing reduced design space, and intricate mounting schemes constrained by panel stamping limitations. These factors necessitate the development of innovative joinery strategies and structural definitions to maintain durability targets, including achieving 25,000–30,000 slam cycles without failure, while preserving luggage space. This paper
Beryl, JoshuaMohanty, AbhinabUnadkat, SiddharthSelvan, Veera
In modern four-wheelers, seat suspension systems play a crucial role in enhancing occupant comfort by mitigating the effects of road unevenness and vibrations. Among these systems, active suspension mechanisms offer advanced performance through complex assemblies involving welded, riveted, and bolted joints. This study investigates the failure of an air spring bracket - a critical component of a pneumatic active suspension system - manufactured by Gas Metal Arc Welding (GMAW) of two dissimilar ferrous materials which are likely to be SAPH440 and S355J2. These different materials were used based on mechanical properties required to perform by their particular part. System level validation tests were conducted to ensure the reliability of the seat suspension system. The one of the validation tests is continuous cyclic fatigue test which is carried out on the complete seat assembly. However, during vibration / cyclic endurance testing, premature failures were observed near the weld joints
Patale Jr, ReshmaPinjari, Jayant NamdevBali, Shirish
The Automotive industry widely uses cast iron due to its better mechanical performance and cost-effectiveness. However, repair welding or assembly of cast iron components remain highly challenging due to the material’s high carbon content, inherent brittleness, rapid thermal conductivity, and complex microstructural transformations. Multi-pass welding exacerbates these challenges by subjecting materials to repeated thermal cycling, accumulating residual stress, and inducing distortion – all of which potentially degrade the integrity of welded joints. A comprehensive understanding of welded joint behavior is essential to effectively mitigate these effects. Finite element analysis (FEA) serves as a powerful tool, enabling accurate prediction of thermal profiles, phase transformations, residual stress development, and resulting deformations. These valuable insights are critical for optimizing welding processes and enhancing overall joint quality. This study investigates and validates the
Vidhate, DigambarNalawade, RahulDabhadkar, MandarVaidya, AbhijitAmmasi, VinothRajagopalan, Sridhar
This study focuses on the investigation of wheel rim failures near weld zone during repeated cornering induced by interference between the rim and disc during the wheel manufacturing assembly process. Strain gauges were employed to capture real-time stress and strain distributions at critical zones during interference fitting. The experimental results revealed that improper interference levels lead to significant stress concentrations, often surpassing the material's elastic limit, initiating micro-crack formation and promoting fatigue failure. Detailed strain analysis indicated that both radial and axial stresses contribute to long-term structural degradation. The study highlights the critical role of dimensional tolerances, surface finishes, and assembly forces in minimizing stress-induced failures. Recommendations are provided for optimizing design and assembly practices to enhance the durability and reliability of automotive wheels.
P, PraveenDEsigan, LakshmipathyK, ChandramohanC, Santhosh
Friction stir welding (FSW) of Al 6063 alloy plates of 6 mm thickness was investigated in the present study for exploring the mechanical attributes of the welded joints. The tool profile significantly influences the quality of joints produced by FSW. In the current study, the influence of tool profile and FSW process parameters on the FSW weld characteristics of similar joining of Al 6063 plates has been investigated. The effect of FSW tool rotational speed (TRS) and tool travel speed on the FSW weld properties, mainly microstructure characteristics, microhardness, and ultimate tensile strength (UTS), have been studied. Comparison of two different tool profiles, namely taper and cylindrical tool, has also been examined. The effect of transient temperature distribution has also been studied for varying FSW process parameters. When increasing the tool’s rotational speed from 800 to 1200 rpm at a fixed traverse speed of 80 mm/min, a rise in peak temperature is observed. Conversely
Kumar, PramodKumar, VikashKumar, GulshanArif, AbdulPrasad, Chitturi RamZubairuddin, M.
High-power fiber lasers have become increasingly indispensable tools in automotive manufacturing over the past two decades. They are now widely deployed in welding and brazing applications for body-in-white, powertrains, engine components, and more.
The need to reduce vehicle weight without compromising safety drives the use of advanced high-strength steels (AHSS) in the automotive industry. Laser welding is a widely employed technique for joining dissimilar materials due to its high precision and small heat-affected zone (HAZ). However, differences in the chemical composition and thermomechanical properties of the materials can create heterogeneous microstructures in the fusion zone (FZ) and HAZ, directly impacting the mechanical properties of the welded joint. This study aims to evaluate the relationship between microstructure and mechanical properties in laser-welded joints of dissimilar automotive steels. The objective is to understand how microstructural transformations affect weld strength, ductility, and toughness, contributing to process parameter optimization and improved structural performance. Microstructural analysis will be performed using optical microscopy, and mechanical tests, such as tensile testing and
Santos, dos Flávio NunesReis de Faria Neto, dos AntonioDias, Erica XimenesMartins, Marcelo SampaioSantos Pereira, dos Marcelo
This specification covers the requirements for producing brazed joints in parts made of steels, iron alloys, nickel alloys, and cobalt alloys by use of nickel alloy filler metal.
AMS B Finishes Processes and Fluids Committee
Finland-based Metos Oy, a manufacturer of professional stainless steel kitchen equipment, needed a welding solution that could deliver flawless, pressure-rated welds for small batches of high-spec products, which feature tubular structures and circular shafts that required continuous, precision welding.
Over the past 25 years, the heavy fabrication and construction equipment industry has experienced significant transformation. Driven by a global surge in demand for construction machinery, manufacturers are under increasing pressure to deliver higher volumes within shorter timelines and at competitive costs. This demand surge has been compounded by workforce-related challenges, including a declining interest among the new generation in acquiring traditional manufacturing skills such as welding, heat treatment, and painting. Furthermore, the industry faces difficulties in staffing third-shift operations, which are essential to meet production targets. The adoption of automation technologies in heavy fabrication and construction equipment manufacturing has been gradual and often hindered by legacy product designs that were optimized for conventional manufacturing methods. As the industry transitions toward smart, connected manufacturing environments under the industry 4.0 paradigm, it
Saseendran, UnnikrishnanBhorge, Pankaj
This paper presents a novel approach to automated robot programming and robot integration in manufacturing domain and minimizing the dependency on manual online/offline programming. Traditional industrial robots programming is typically done by online programing via teach pendants or by offline programming tools. This presents a major challenge as it requires skilled professionals and is a time-consuming process. In today’s competitive market, factories need to harness their full potential through smart and adaptive thinking to keep pace with evolving technology, customer demand, and manufacturing processes. This requires ability to manufacture multiple products on the same production line, minimum time for changeovers and implement robotic automation for efficiency enhancement. But each custom automation piece also demands significant human efforts for development and maintenance. By integrating the Robot Operating System (ROS) with vision-based 3D model generation systems, we address
Hepat, Abhijeet
With the global increase in demand for construction equipment, companies face immense pressure to produce more products in a competitive and sustainable way by utilizing advanced manufacturing technologies. Additionally, the need for data analytics and Industry 4.0 is increasing to take better decisions early in the development cycles and during the production phase. Advanced manufacturing processes & adopting Industry 4.0 is the only viable solution to address these challenges. However, the implementation of advanced manufacturing processes in heavy fabrication and construction equipment factories has been slow. A significant challenge is that the products being produced were originally designed for conventional manufacturing processes. When factories are becoming smart and connected through Industry 4.0 solutions, companies must reconsider many established assumptions about advanced manufacturing processes and their benefits. To maximize efficiency gains, improve safety standards
Bhorge, PankajSaseendran, UnnikrishnanRodge, Someshwar
Yamaha Motor Engineering Co., Ltd. provides plastic processing technology based on fuel tank press forming technology, and is developing various plastic processing methods, including forging, and developing mold equipment to realize them. This time, the core parts of the YECVT unit mounted on Yamaha Motor Co., Ltd.'s small premium scooter "NMAX" were not made by welding individual parts to each other, but by integrally forming them from a single thick plate using the cold forming method, resulting in lightweight, compact, high-strength, high-precision parts. By incorporating a composite plastic processing method that takes advantage of the characteristics of the material while making full use of analysis technology and mold technology, we were able to develop a composite plastic processing method (plate forging method) that creates new added value and mass produce it. In addition,this development has made it possible to achieve a thickness increase of 1.7 times the standard material
Hongo, HironariTamaru, ShogoUda, Shinnosuke
Innovators at NASA Johnson Space Center have developed additively manufactured thermal protection system (AMTPS) comprised of two printable heat shield material formulations. These formulations are directly applied by 3D printer or other robotic extrusion system and bonded to a spacecraft to devise a heat shield suitable for atmospheric entry. This technology could significantly decrease heat shield or thermal protection system (TPS) fabrication cost and time.
In this study, the optimization of robotic gas metal arc welding (GMAW) parameters for joining hot-rolled ferritic-bainitic FB590 steel sheets with a thickness of 2.5 mm was investigated. The main objective was to evaluate the effect of wire feed speed and welding speed on the penetration depth, throat thickness, and mechanical performance of the welded joint. A series of welding experiments were carried out with wire feed speeds ranging from 50 cm/min to 100 cm/min and welding speeds ranging from 5 cm/min to 15 cm/min. Tensile and microhardness tests were carried out to evaluate the structural integrity of the welded joints. The results show that increasing the wire feed speed significantly improves the weld penetration and throat thickness, especially at constant welding speeds. The most suitable combination was found to be 70 cm/min wire feed at 8 cm/min travel speed and 100 cm/min wire feed at 12 cm/min and 15 cm/min travel speeds. The microhardness in the heat-affected zone
Babir, NaimeÜzel, Uğur
This document is reissued for application to helicopters. It is primarily intended to apply to the engine or engines, but it shall also apply to fire protection of lines, tanks, combustion heaters, and auxiliary powerplants (APU). Post-crash fire protection is also discussed.
S-12 Powered Lift Propulsion Committee
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Self-piercing riveting (SPR) is a key joining method in multi/thin-material automotive structures, yet accurately predicting the mechanical strength of SPR joints remains challenging due to numerous influencing factors. Empirical engineering equations [1] provide a foundation for estimating lap-shear and cross-tension strength but require several geometric parameters that are often unavailable in the design phase. To address this limitation, we extract and leverage the core physical relationships embedded in these formulas. By reformulating the dependence of joint strength on the yield strength and total thickness of the sheet stack as practical regression models, we enable strength prediction using only commonly available material properties. Furthermore, a Bayesian convolutional neural network (BCNN) model is developed to incorporate additional material features, offering improved prediction accuracy and uncertainty quantification.
Soproni, IstvanWomack, DarrenLiu, ZongyueBalaji, AshwinKulange, Deepak
Plasma pens integrated into production lines provide targeted plasma treatments that reduce failure rates by improving adhesion and bonding in various critical applications.
This study aims at examining the effect of tool rotational speed on the microstructural and mechanical properties of friction stir welded joints of AA6061 aluminum alloy, both pre- and post-heat treatment. The quality of the joints was assessed initially through tensile, hardness, and charpy impact tests, as well as microscopic observations. During the second stage, solid solution heat treatments were conducted at 535°C, followed by aging on additional specimens welded at identical speeds. The latter underwent hardness tensile tests and microscopic examinations. A comprehensive assessment of the outcomes from various tests validated the influence of metallurgical phenomena, including recrystallization, precipitation, and structural defects on overall resistance. The results showed an improvement in strength, ductility, and impact energy was observed in the case of welding at high rotation speed (1400 rpm). At the same speed, ductility almost doubled after post-weld heat treatment
Bouchelouche, FatimaDebih, AliOuakdi, Elhadj
This specification covers flash welded rings made of ferritic and martensitic corrosion-resistant steels.
AMS F Corrosion and Heat Resistant Alloys Committee
Medical tubing is an essential component of countless healthcare applications, from intravenous (IV) and oxygen lines to catheters and diagnostic equipment. These tubes, often made of clear flexible polymers, must be produced to exacting standards: free of contaminants, strong under pressure, and biocompatible. However, the joining process to connect these tubes can introduce significant manufacturing challenges.
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