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Highlights Self‐piercing riveted bonded (SPRB) joints are widely used in body‐in‐white (BIW) to connect dissimilar materials owing to their high fatigue and electrochemical performance. However, the strength of the SPRB joint has been found to be inferior to that of self‐piercing riveted (SPR) joints, owing to the reduction in undercut induced by the introduction of an adhesive, especially under pull‐out loading conditions. Interestingly, the mechanical strength improved when the rivet cavity was pre‐embedded with an adhesive. Before the riveting process, the rivet cavities in SPRB joints were pre‐embedded with 0.01, 0.02, and 0.03 mL of adhesive, namely them PSPRB‐V1–V3, respectively. Finite element (FE) models of SPRB and PSPRB joints were developed to analyze their formability and mechanical properties. The simulated and experimental results showed that the hydraulic pressure in the rivet cavity increased as the pre‐embedded adhesive volume in the rivet cavity increased during the riveting process, which further improved the undercut, microhardness, effective bearing area, and mechanical properties of joints. Among the prepared PSPRB joints, the PSPRB‐V3 joint exhibited the best undercut and optimal mechanical properties. Specifically, its undercut and peak force increased by 16.43% and 12.87% compared with those of SPRB joints. These findings provide important guidance for designing steel‐aluminum SPRB joints that require high‐bearing capabilities. The effect of pre‐embedded adhesive on the SPRB joint cross‐section was studied. Failure mechanisms of the SPRB and PSPRB joints were investigated via FEM. The better PSPRB joint performance over SPRB joints was elucidated. The stress–strain history was considered in the FE model of the joint failure process. Strengthening mechanism of pre‐embedded adhesive in the rivet cavity was discussed. [ABSTRACT FROM AUTHOR]

As a cathode material for potassium-ion batteries (PIBs), manganese-based layered oxides have attracted widespread attention due to their low cost, ease of synthesis, and high performance. However, the Jahn-Teller effect caused by Mn3+ and the irreversible phase transformation of the structure leads to poor cycle stability, limiting the development of layered oxides in PIBs. Herein, we demonstrate the use of phase-transition-free CaTiO3 as rivets in K0.5Mn0.9Ti0.1O2 by a simple solid-state method. As verified by the in situ X-ray diffraction, the CaTiO3 rivets effectively prevent the slippage of the transition metal layer during charge and discharge, inhibiting structural degradation. As a result, the obtained K0.5Mn0.9Ti0.1O2-0.02CaTiO3 shows excellent cycling stability and rate performance, with high capacities of 119.3 and 70.1 mAh·g-1 at 20 and 1000 mA·g-1, respectively. At 200 mA·g-1, the capacity retention remains 94.7% after more than 300 cycles. This work represents a new avenue for designing and optimizing layered cathode materials for PIBs and other batteries. [ABSTRACT FROM AUTHOR]

Through theoretical analysis, finite element simulation, and experimental verification, he reverse research from 1 to 0 on basic applications of screw type blind rivets was studied. The evoution and equilibrium of forces during installation processes were established. The relationships of intallation performance (preload, diameter and height of blind head) and key geometric parameters were obtained. And a parametric module was developed, which might achieve automatic modeling and imulation calculations. The results have guiding significance for enhancing connection reliability, imroving economic benefits, and for promoting the processes of independent research and development f the screw type blind rivets [ABSTRACT FROM AUTHOR]

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

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

This study focuses on the effects of reducing the diameter of rivets used in Friction Riveting due to the need for downscaling when joining assemblies on a smaller scale. The Friction Riveting process has shown promising feasibility for a variety of material combinations and applications in the transportation industry. Recent research has explored the potential application of this technique in electronics, specifically for the assembly of printed circuit boards (PCBs), using AA-2024-T351 rivets on thin glass-fiber-reinforced epoxy substrates (FR4). The joint formation of joints produced with PCBs was investigated in terms of process temperature evolution, microstructural changes, and mechanical properties. Joints were obtained at process temperatures ranging from 285 ºC to 368 ºC. The use of 4 mm rivets resulted in extensive delamination, weak joint mechanisms, and cracking, impaired by the different coefficients of thermal expansion of the materials involved. Reducing the rivet diameter to 3 mm significantly improved joint quality. A further reduction to 2.5 mm minimized delamination but led to insufficient anchorage and cracking. Joints produced with a 3 mm rivet diameter achieved the highest ultimate tensile force of 276 N. This study sets the foundation for applying the Friction Riveting process to practical PCB assemblies, demonstrating that optimizing the process parameters to the diameter-to-thickness ratio can balance sufficient rivet anchoring, minimize delamination, and reduce cracking. [ABSTRACT FROM AUTHOR]

In aircraft panel assembly, the interference fit unevenly distributed along the axial direction of the rivet holes leads to an uneven stress–strain field around the rivet holes. The uneven stress–strain fields of single rivets, when accumulated through multiple rivets, result in overall bending and twisting deformation, severely impacting the assembly coordination quality of the panel. This study introduces a numerical model using a single row of multiple rivets to explore cumulative deformation during both sequential and changing order riveting. The results show that the deformation in sequential riveting is mainly bending-oriented towards the driven head side, with the maximum displacement exhibiting a fluctuating accumulation trend as the number of rivets increase. In contrast, a changing riveting order can lead to a reduction in deformation accumulation. To reveal the technological mechanism behind deformation accumulation during the riveting process, a model correlating to the residual stress field was established. It was indicated that the continuous increase in the maximum equivalent bending moment in the axial section is the primary factor leading to deformation accumulation. Based on this finding, a pre-bending suppression method aimed at reducing the local maximum equivalent bending moment was proposed. Numerical calculations and experimental results showed that the maximum displacement of the specimen was reduced by 73.27%, proving that this method can effectively suppress the cumulative increase in deformation. [ABSTRACT FROM AUTHOR]

The study presented focuses on material research of La Tène rivets and represents the very first study conducted into this class of archaeological finds from the Bohemian region. The rivets examined come from two significant archaeological sites situated in this geographical area—a hillfort Kolo near Týnec nad Labem and an oppidum in Stradonice. The sets of the rivets selected for the study were dated to the Late La Tène period (second–first century BC)—in the context of Western Europe, the term Celtic period can also be found. Thorough material research of the objects utilised a range of methods such as scanning electron microscopy with energy dispersive analyser, atomic absorption spectrometry, X-ray micro-tomography scanning, laser ablation-inductively coupled plasma-mass spectrometry, and Raman spectrometry. As a result, the research has identified and described three different technologies used to produce the rivets. The rivets uncovered there were mostly produced by casting from a bronze alloy or by putting wrought iron pins into the bronze melt of rivet heads. In addition, a minority of the rivets were produced using forged wrought iron with their heads plated with a very thin bronze plate. The results of the elemental analysis showed that several of the rivets and most of the rivet heads were made of bronze alloys with a tin content of 2–10 wt.%. The lead content of bronze alloy rivets from both sites varies from 0.2 to 10.1 wt.%. It can be assumed, that lead was intentionally added to the bronze melt used to produce the majority of the artefacts examined. Also, several bronze rivet heads were found to be decorated with enamel, which is a type of soda-lime-silica high lead glass coloured with crystals of Cu2O (the Colour of the enamel was predominantly red). In conclusion, two different groups of enamels were distinguished: (a) enamels with PbO up to 20% and (b) enamels with a higher content of PbO reaching up to 40%. [ABSTRACT FROM AUTHOR]

In this work, a special electromagnetic riveting punch with a convex die was proposed to improve deformation uniformity of rivets. Electromagnetic riveting experiments with the special and conventional flat punch were employed to contrastively investigate microstructure evolution and mechanical properties. Results showed that the width of adiabatic shear bands in the flat headers was narrower than that in the concave headers. The deformation uniformity of the concave headers was better. Microhardness distributions in concave rivet headers were more uniform than that in flat rivet headers. The plastic flow toward rivet hole was larger for the concave headers, resulted in a greater interference-fit strengthening effect of riveted structures. The difference in shear loads of riveted structures with the flat and concave headers was not significant. The riveted structures with concave headers had better vibration absorption effect. The shear friction effect on the fracture surface was more pronounced. The maximum pull-out loads of riveted structures with the flat and concave headers were respectively 13.4 kN and 13.9 kN, showing that riveted structures with concave headers had good resistance to pull-off. By changing the geometric shape of the punch, the quality of the riveted structures has been improved. Highlights: Special punch was used for electromagnetic riveting of aluminum alloy structures. The microstructure distributions of different riveted header were investigated. The effect of microstructure distributions on interference-fit values was analyzed. Microhardness and mechanical properties of riveted header were studied. The strengthening mechanism of special punch on the riveted header was revealed. [ABSTRACT FROM AUTHOR]

In experiments of aviation motor bearings, when the deep-groove ball bearings are subjected to an overturning moment at high speed, it often happens that the rivet on the cage breaks and the debris invades the raceway, resulting in bearing failure. To address the problem of early failure of deep-groove ball bearing cages and rivets in aviation motors, the causes of early failure were analyzed from the aspect of cage design in this study. The influence of the raceway and cage structure parameters on the dynamic contact characteristics of the rolling element and cage under the action of overturning torque were analyzed, the weak link of the cage was determined, and the cage design parameters were optimized. The results show that with an increase in the cage width and pocket radius, the impact force between the ball and cage first decreases and then increases, and the tilt angle of the cage gradually decreases. A larger channel radius and smaller clearance can slow down the interaction between the cage and the rolling element and make the cage run more smoothly. Increasing the thickness of the cage can ensure that the rivet part of the cage is at a low stress level, and the risk of premature fatigue failure at the rivet part can be reduced by maintaining a small gap–fit relationship between the rivet and rivet holes. The research results indicate that the working condition adaptability of the bearing cage for aviation motors can be improved, and the design method for this type of bearing can be enhanced. [ABSTRACT FROM AUTHOR]

Copyright of Foundry Technology (1000-8365) is the property of Foundry Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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

The development of potassium‐ion batteries (KIBs) relies on the exploration of stable layer‐structured oxide cathode materials and a comprehensive understanding of ion storage and diffusion behaviors. A multiphase riveting‐structured O3/P2/P3‐Na0.9[Ni0.3Mn0.55Cu0.1Ti0.05]O2 (Tri‐NMCT) is employed as cathode material for KIBs. It demonstrates an initial discharge specific capacity of 108 mA g−1 at current density of 15 mA g−1 in the voltage range of 1.5–4 V. Excellent cyclic stability is exhibited as well with a high 83% capacity retention after 600 cycles at a higher current density of 300 mA g−1. Based on the in‐situ XRD, it reveals that the P2 phase offers a more stable triangular prism site compared to the O3 phase. This stability inhibits the undesired phase transition from P3 to O3 during discharge, thereby ensuring the long‐term cyclic performance. Furthermore, Density of state (DOS) calculations and migration barrier analyses indicate a preferential migration of K+ ions to the P2 phase due to the lower Fermi level. This observation elucidates the structural preservation of the P3 phase during K+ embedding. Overall, this work sheds light on Tri‐NMCT as a promising cathode material for advanced KIBs. [ABSTRACT FROM AUTHOR]

Analytical modeling of the squeezing force for aircraft wings and fuselage panels in the existing literature usually assumes uniform deformation of the rivets, while in reality, the deformation of the rivets is non-uniform. To achieve high-quality squeezing force modeling, this paper introduces Coulomb's friction and four critical adjustments to the original equation: the non-uniform rivet/sheet interference along the sheet's hole axial ordinate; the barreling effect when calculating the driven head's volume; the spring-back of the driven head's dimensions; the modified height of the driven head; and the modified sheet-hole expanded diameter considering the convex structure of the driven head. The calculated values of the proposed new model demonstrate an improved level of accuracy, particularly under squeeze ratios commonly encountered in the aerospace industry. [ABSTRACT FROM AUTHOR]

Rivet connection is one of the most important connection technologies. The main factors affecting the rivet-forming quality of riveted structures are squeezing force, squeezing velocity, and materials of rivets and plates, which significantly impact the damage and failure of riveted holes in riveted structures. This paper provides a detailed study of the rivet-forming quality of riveted structures under different dynamic loads. A theoretical analysis method for the nonlinear dynamic plastic behavior of riveted structures is proposed to predict and investigate the rivet-forming quality of riveted structures under different squeezing forces, velocities, and materials. The proposed theoretical analysis method for the rivet-forming quality of riveted structures is conducted using the explicit dynamics method. Furthermore, the nonlinear dynamic plasticity theory method and nonlinear explicit dynamics model calculation results of riveted structures are compared with measured and Ultra Plus field scanning electron microscope scanning values. The results confirm the accuracy of the nonlinear dynamic plasticity theory method for riveted structures. In addition, the effects of different squeezing forces, velocities, rivet material, and plate material properties on the rivet-forming quality of riveted structures are also studied. This paper proposes a theoretical analysis method for the rivet-forming quality of riveted structures, providing an optimal squeezing force and velocity for rivet hole damage and rivet failure under different rivet and plate materials. [ABSTRACT FROM AUTHOR]

To improve the reliability of the connection of various steel/aluminum dissimilar materials, an integrated optimization method of material-structure-process-performance is proposed to realize the optimal design of process parameters. First, the Johnson–Cook material model and failure fracture model are established to ensure the accuracy of the simulation model. Then, an integrated simulation analysis for self-piercing riveted joint forming and tensile mechanical performance is established considering the residual information of the joint forming process. Compared with the experimental results, the accuracy of the established model is higher than the model without considering the residual information. Finally, a hybrid sequence approximate optimization that comprehensively considers the forming quality and tensile mechanical performance is constructed to determine the optimal riveting parameters. Compared with the initial design, the maximum pull-out force, maximum shear force, and maximum peeling force of the optimized design for DC01 and 5754 rivets are increased by 35.66%, 8.6%, and 22.43%, respectively, and the maximum pullout force, maximum shear force and maximum peeling force of the optimized design for HC280 and 5754 rivets are increased by 1.490%, 1.292%, and 6.867%, respectively. Moreover, the accuracy and efficiency of self-piercing riveting process design are improved. [ABSTRACT FROM AUTHOR]

This article studies a general regression model for a scalar quality response with mixed types of process predictors including process images, functional sensing signals, and scalar process setup attributes. To represent a set of time-dependent process images, a third-order tensor is employed for preserving not only the spatial correlation of pixels within one image but also the temporal dependency among a sequence of images. Although there exist some papers dealing with either tensorial or functional regression, there is little research to thoroughly study a regression model consisting of both tensorial and functional predictors. For simplicity, the presented regression model is called functional linear regression with tensorial and functional predictor (FLR-TFP). The advantage of the presented FLR-TFP model, which is compared to the classical stack-up strategy, is that FLR-TFP can handle both tensorial and functional predictors without destroying the data correlation structure. To estimate an FLR-TFP model, this article presents a new alternating Elastic Net (AEN) estimation algorithm, in which the problem is reformed as three sub-problems by iteratively estimating each group of tensorial, functional, and scalar parameters. To execute the proposed AEN algorithm, a systematic approach is developed to effectively determine the initial running sequence among three sub-problems. The performance of the FLR-TFP model is evaluated using simulations and a real-world case study of friction stir blind riveting process. [ABSTRACT FROM AUTHOR]

Integrating diverse materials and functions into highly additive produce has piqued global interest due to the increasing demands of intelligent soft robotics. Nevertheless, existing assembly techniques, especially supramolecular assembly which heavily rely on precise chemical design and specific recognition, may prove inadequate when confronted with diverse external demands. Inspired by the traditional mechanical assembly, rivet connection, herein, a thermo‐responsive hydrogel with unidirectional shape‐morphing is fabricated and a stable mechanical assembly is constructed by emulating the rivet connection mechanism. This system employed poly(acrylamide‐co‐acrylic acid) [P(AAm‐co‐AAc)] to induce continuous swelling and hexylamine‐modified polyvinyl alcohol (PVA‐C6) as a molecular switch to control the swelling process. The hydrogel rivet, initially threaded through pre‐fabricated hollows in two components. Subsequently, upon the disassociation of alkane chains the molecular switch would activate, inducing swelling and stable mechanical assembly via anchor structures. Moreover, to enhance the assembly strength, knots are introduced to enhance assembly strength, guiding localized stress release for programmed deformations. Additionally, the system can be remotely controlled using near‐infrared light (NIR) by incorporating photo‐thermal nanoparticles. This work presents a universal and efficient strategy for constructing stable mechanical assemblies without compromising overall softness, offering significant potential for the fabrication of integrated soft robots. [ABSTRACT FROM AUTHOR]

Riveting quality is crucial to an aircraft's overall aerodynamic performance and fatigue life. In order to effectively extract the point cloud of rivet heads and analyze the quality of riveting, this paper proposes a rivet flushness detection method based on the normal vector-density clustering algorithm. First, initial point cloud data sampling is based on normal vectors. Then, the density clustering algorithm is employed to cluster and extract the point cloud of rivet heads. Subsequently, the obtained point cloud of rivet heads is subjected to the random sample consensus algorithm for fitting the contour and obtaining the model parameters of the rivet head. The paper introduces a quality detection metric to describe the flushness of the rivet head. Finally, the proposed method is applied to analyze the skin and theoretical model point cloud data of rivets. The results demonstrate that the proposed method yields small errors and high accuracy compared to theoretical values. The method is further employed for quality detection and analysis of rivet flushness in practical aircraft engineering. A visualization system for rivet flushness quality detection is developed to represent the results visually. This system enhances the intuitive identification of rivet detection outcomes. Therefore, the proposed method holds significant engineering application value in rivet flushness detection. [ABSTRACT FROM AUTHOR]

• Decayed artefacts are especially problematic to remove via archaeological excavation. • Micro-CT scanning soil blocks containing artefacts benefits conservation. • Georefencing tags embedded in the soil blocks enrich the useability of the data. • Information garnered impactful for interpretation and conservation strategies. • Georefenced 3D models derived from micro-CT-data are a powerful resource. The cultural heritage sector has increasingly explored the use of micro-CT (µCT) across numerous projects seeking to better understand past cultures and the materials they have left behind. As such, the role of micro-CT (µCT) is still being developed and projects continue to show novel ways that the technology can be adapted to. The Gjellestad ship, located in Halden (Østfold in Viken), Norway, is dated to the Viking Age and was found in a poor state of preservation. Both organic and metallic materials were deteriorated to the degree that standard excavation methods would have resulted in further damage to, or even the destruction of, these elements. A new approach was needed, and this presented an opportunity to explore the use for µCT as a documentative tool for field archaeology and conservation. As the remaining rivets were too fragile to handle directly, they were removed together with the surrounding matrix as soil blocks. To retain important stratigraphic and position information, a georeferencing system was developed that would be visible to µCT and included within each soil block. This enabled the spatial (re)positioning of the soil blocks by use of 3D GIS and in alongside with other spatial documentation gathered at the time of excavation. The quantity of soil blocks will give us a large dataset to work with and, although we continue to document the soil blocks with µCT, we now can discuss our preliminary results pertaining to the positive impact that µCT has for the documentation, conservation, and reconstruction of cultural heritage. [Display omitted] [ABSTRACT FROM AUTHOR]

This paper presents the possibility of forming a pressed joint between two 1.5 mm thick sheets made of HX340 steel. The joint was formed using an additional deformable steel rivet with a hardness of 400HV1. Different distances of rivet pressing below the initial surface of the upper sheet were chosen: 0, 0.15, 0.30, 0.45 and 0.60 (in mm). For the mentioned rivet-pressing distances, forming tests were performed using an "SKB" die with three die depths: 1.45, 1.60 and 1.75 (in mm). Observations and measurements of the characteristic geometric dimensions of the interlock were made. Furthermore, the strength of the clinch-riveted joints was analysed. Changing the depth of the die by 20%, i.e., from hd = 1.45 mm to hd = 1.75 mm for the same rivet press-in depth (of = 0%), resulted in a 12% reduction in the forming-force value. The maximum load capacity of the joint in the shear test decreased by 3.5% for the mentioned joint variant. The greater the rivet press-in depth used in the joint (of), the greater the value of the interlock size (tu). Increasing the value of rivet-pressing depth below the initial surface of the upper sheet from 0 mm to 0.6 mm resulted in an increase in the size of the interlock (tu) by 136% (for hd = 1.45 mm), by 128% (for hd = 1.60 mm) and by 85% (for hd = 1.75 mm). [ABSTRACT FROM AUTHOR]

A large passenger airplane experienced an inflight rapid decompression and was forced to make an emergency landing. Post-accident inspection revealed that a section of the fuselage skin on the top portion of the airplane (crown) had fractured and flapped open during the flight. The National Transportation Safety Board (NTSB) Materials Laboratory examination of the fuselage structure determined that multiple-site damage (fatigue cracking) originated at the skin panel of a lap joint from areas of improperly drilled rivet holes. Fatigue crack growth analysis on the fracture face of the skin panel via quantitative fractography was performed by scanning electron microscopy revealed that cracking started approximately when the airplane entered service. [ABSTRACT FROM AUTHOR]

Within the double-sided countersunk riveting process of aircraft wings with a composite wedge structure, riveting consistency is poor, and composite damage is severe, which seriously affects the performance and reliability of the aircraft structure. This paper used the principal stress method to establish a stress model of countersunk riveting, and, based on the analysis of the stress on the structure during the pressure-riveting process, a composite structure rivet was designed. A finite element simulation model of the double-sided countersunk riveting of composite wedge structures' composite rivets was established. The influences of the structure and the matching parameters of composite rivets on both the plastic flow of pressure riveting and the compressive stress of the structure during the pressure-riveting process were analyzed. The structural parameters and riveting process of composite rivets were optimized. The results show that the composite rivet structure could significantly reduce the contact-compressive stress at the riveting joint by more than 20%, thereby reducing the damage caused by the riveting to the composite material. For 4 mm rivets, an aperture of 4.04~4.06 mm can achieve precise relative interference riveting at 0.6% to 1.0%. Employing a 2.6 mm rivet elongation can exactly fill the countersunk hole of the wedge. [ABSTRACT FROM AUTHOR]

Research on the efficiency and quality issues faced in aircraft assembly was conducted in this article. A new method of human–machine collaborative riveting was proposed, which combined the flexibility of manual collaboration with the precise control of automatic riveting. The research works include: (1) a theoretical model of pneumatic hammer riveting was established to clarify the principle and parameters of riveting process. (2) A smart bucking bar was designed to support the data collection and extraction of manual collaborative riveting process. (3) An automatic riveting experimental platform was designed to test the automatic riveting process incorporating the extracted manual riveting process parameters, and further an optimization strategy was proposed for the automatic riveting process. (4) A human–machine collaborative riveting experimental platform was developed to conduct the verification work. Through the theoretical analysis, experimental research, system scheme design, and process parameters optimization, the application and verification of human–machine collaborative assembly technology have been achieved. This technology is expected to be comprehensively promoted in the field of aircraft manufacturing, and for breaking through the current difficulties of low production efficiency and poor assembly quality control. [ABSTRACT FROM AUTHOR]

Unique friction-based self-piercing riveting (F-SPR) was employed to join high-strength, low-ductility aluminum alloy 7055 for lightweight vehicle applications. This study aimed to maximize the joint strength of the AA7055 F-SPR joint while avoiding cracking issues due to low ductility at room temperature. A fully coupled Eulerian–Lagrangian (CEL) model was employed to predict the process temperature during F-SPR, and the temperature field was then mapped onto a 2D axisymmetric equivalent model for accelerated numerical analysis. The geometry, dimensions, and material strength of the rivet, as well as the depth of the die cavity and plunging depth, were investigated to enhance joint formation. Also, a static finite-element analysis model was developed to predict and analyze the stress distribution in the rivet under different mechanical testing loading conditions. Overall, the numerical model showed good agreement with the experiment results, such as joint formation and mechanical joint strength. With the aid of virtual fabrication through numerical modeling, the joint design iterations and process development time of F-SPR were greatly reduced regarding the goal of lightweight, high-strength aluminum joining. [ABSTRACT FROM AUTHOR]

The sustainability of the manufacturing industry is of special importance to increase the protection of the environment. The production of fasteners like self-piercing rivets, however, is costly, time-consuming and energy-intensive. The heat treatment and the coating, which are mandatory in conventional self-piercing rivets to achieve adequate strength, ductility and corrosion resistance, are especially crucial in this respect. Within this paper, an approach for an increase in the sustainability in fastener production is presented. The use of alternative, high strain hardening stainless steels as rivet material enables a shortening of the process chain, because post treatment of the rivets after they are formed can be omitted. As the change in rivet material and processing causes some issues along the process chain, the focus of this paper is on the holistic evaluation of the challenges within the forming of high strain hardening steel and the impact of the changed rivet properties on the joining result. [ABSTRACT FROM AUTHOR]

This article explores the challenges we faced when translating and editing the autograph letters of Anna Maria Van Schurman that span four decades from 1631 to 1669. Van Schurman was regarded as the most learned woman in Europe throughout the seventeenth and well into the eighteenth century. Most of the letters, primarily in Latin, are addressed to André Rivet (1572–1651) and Constantijn Huygens (1596–1687), towering figures in the Dutch Republic and the Republic of Letters. Our greatest challenge in translating and editing the letters was rhetorical: to discern and identify the gender dynamics at work when Van Schurman self-consciously entered the lettered world of male power and authority. Presenting the distinctive epistolary relations Van Schurman shared with Rivet and Huygens necessitated the identification of particularities in content, tone and material culture. Similarly, exploring these relations meant highlighting subtle and complex material markers in Van Schurman's letters, such as handwriting, visual presentation, and closing subscriptions and signatures, as well as postscripts, deferential spacing and quantity of paper used. We present Van Schurman's manuscript exchanges with Rivet and Huygens as a window into how a learned woman negotiated the challenges of epistolary networking in the Republic of Letters. [ABSTRACT FROM AUTHOR]

To investigate the low-speed impact response of the BR1200HS steel and AA6082 aluminum alloy self-piercing riveted (SPR) joint, low-speed impact tests with impact energies of 2.5 J, 5.0 J, 7.5 J, 10.0 J, 12.5 J, 15.0 J, 20.0 J, and 30.0 J were conducted utilizing a drop hammer impact tester. The results show that with the increased impact energy, the visual breakages of the SPR joints become more severe. The maximum impact energy the joints can sustain ranges from 10.0 J to 12.5 J. When the impact energy is less than 12.5 J, the contact force/energy–time curves show similar variations. Moreover, as the impact energy increases, total uptake energy value (Et), maximum uptake energy value (Ef), and maximum contact force (Fm) of the joints increase gradually. The low-speed impact energy has little effect on the maximum static tensile force of the impacted joints. However, the residual energy values decrease with the increase in impact energy. The tensile failure form of the joints is the pulling out of the rivets from the lower plates, and the low-speed impacts have no significant effect on the tensile failure form of the joints. [ABSTRACT FROM AUTHOR]

In recent years, the transportation industry has faced the challenge of cutting costs, meeting increasingly stringent environmental regulations, and significantly increasing transportation volumes. One approach to meeting these challenges is to develop new, improved transportation vehicles using new materials and innovative joining techniques. Multi-material structures are becoming an alternative to body parts. Self-pierce riveting technology plays a crucial role in this process, and hybrid structures depend exclusively on it. In this article, recent advances in self-pierce riveting technology are analyzed to meet today's challenges and future multi-material applications. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to examine the effect of changing some riveting parameters on the riveting quality of a riveted aircraft structure. In this study, riveting was performed by applying friction under pressure. Design/methodology/approach: During this friction riveting process, a feed of 3 mm/min was applied in the axial direction. Rotation speed values of 2,000, 2,200 and 2,400 rpm were selected. A 3-axis die milling machine was used to achieve the required positioning, pressing force and friction effect. 1.27 mm-thick Al 7075-T6 sheets and 2117-T3 forged rivets were used. The feed rate was applied at 1 mm/min in both tensile shear and cross-tensile tests. Findings: The feasibility of friction riveting in 2117-T3 rivets was examined, it was shown that it could be done, and the most suitable rotation value for this process was determined. Originality/value: Clamping force is one of the most important parameters for riveting quality. This study will contribute to a better understanding of the friction-forging riveting process along with the effects of riveting parameters. At the same time, it will lead to more research and expand the application of friction forging riveting to more structural connections. [ABSTRACT FROM AUTHOR]

In this study, the joining of 6061-T6 aluminum alloy and DP590 steel using a M42 steel rivet via friction riveting technique is investigated. The surface morphology and microstructure characterization reveal the formation of an anchor zone that imparts mechanical interlock as well as the formation of metallurgical bonds at the interface of aluminum and steel. A combination of interlocking and bonding results in the achievement of a high load-carrying capacity of 5.7 kN during lap shear testing at room temperature. A finite element-based computational model was developed which accurately predicted the lap shear response of the joint. The model revealed that the metallurgical bond formed during fric-riveting adds 39% peak load strength to the joint. An extensive microstructural investigation, post-lap-shear fractography, and the modeling results, together provided insights on the joint failure mechanism. This study highlights that friction riveting is a promising method for aluminum-to-steel dissimilar joining, which is important for lighweighing automotive vehicles for energy efficiency. [ABSTRACT FROM AUTHOR]

This paper presents an experimental and numerical study on the mechanical quasi-static behavior of self-piercing rivet (SPR) connections with three stacked sheets made from an AA6016-T4 aluminum alloy. The goal was to study the effects of sheet thickness and stack up of the SPR connection under large deformation and failure. Several different types of tests were performed to investigate the initial load-bearing capacity as well as the remaining capacity after partial joint failure. Additionally, the performance of state-of-the-art constraint modeling techniques was evaluated. The parameters for large-scale connector models were found through inverse modeling of the experiments. The models were validated against an additional test configuration where the middle sheet was load-free. [ABSTRACT FROM AUTHOR]

Copyright of Rolling Stock (1002-7602) is the property of Rolling Stock Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The present work addresses the impact of die design (flat die or pip die) and sheet placement on the self-piercing riveting (SPR) of automotive grade CR210 and CR340 galvanized steel sheets. Actual rivet head height, interlock distance, bottom sheet thickness, maximum riveting force, lap-shear fracture load, and fracture modes are monitored. Later, the lap-shear tensile performance of SPR joints is compared with joints made using resistance spot welding (RSW) and friction stir spot welding (FSSW). Both die design and sheet placement impact the SPR outputs significantly. Flat die results in improved rivet penetration irrespective of sheet placement. Maximum riveting force in the case of pip die is higher irrespective of sheet placement. Pip die results in better interlocking than the flat die, irrespective of sheet placement. The effect of die design on lap-shear fracture load and fracture mode is marginal for the sheet combination. However, optimization of sheet placement is critical for SPR. Locating the CR210 (weaker, thinner) sheet at the top would be beneficial if riveting force and interlock distance are referred to. However, if the bottom sheet thickness and tensile-shear fracture load are considered, placing the CR340 (stronger, thicker) sheet on top would be acceptable. Sheet placement has a marginal influence on RSW joint formation and tensile-shear performance. Sheet placement is also critical for FSSW in terms of joint formation. The lap-shear fracture load of RSW joints was higher than that of SPR and FSSW joints. However, SPR joints exhibited significantly higher displacement at fracture than RSW and FSSW. [ABSTRACT FROM AUTHOR]

This paper presents a new solution for shaping the rivet progression of a beverage end. The classic method uses three operations to press the cylindrical rivet using 0.208 mm and 0.203 mm thick sheets. The increasing demand for aluminium alloys is prompting measures to make more efficient use of this raw material. One possible solution is to produce packaging from ever thinner sheets. This requires the design of new tooling and the preparation of an appropriate technological process. A method has been developed to stamp a hexagonal-shaped rivet from 0.200 mm thick sheet metal, increasing the number of stamping operations to four. The proposed method was verified through a numerical analysis using the PAM STAMP 2022.0 software package. It was found that for appropriately shaped tools, sheet thicknesses of the stamped component could be achieved that were not less than those for the currently used technology, thus eliminating any possible break in the material structure. Suitable tools and experimental stamping tests were carried out for the developed process. In the simulations, the material Al5182_iso_Xmm was adopted from the programme database, while the experiments were performed on a laboratory press using AW-5182-H48 sheets with a thickness of 0.200 mm. The purpose of the study was to determine the validity for the proposed method of forming the rivet of the beverage end. [ABSTRACT FROM AUTHOR]

T‐stubs and L‐stubs loaded in tension are generally assumed in contact with a rigid foundation. The prying force and stiffness of these components depend on this hypothesis. For double web angle riveted connections, the angle rests on deformable beam/column web. The objective of the present paper is to take into account the effects of this deformability on the development of the contact area, the rivet forces and the tensile stiffness. An enhanced theory of beam in contact with a tensionless Winkler foundation is adopted in the contact and lift‐off areas. The axial and bending flexibilities of rivets are also considered. A numerical analysis is also performed with ANSYS in order to validate the analytical model. A sensitivity study is conducted on the influence of the thickness of the horizontal leg. The analytical and the numerical results are in good agreement, which confirms the accuracy of the proposed mechanical model. [ABSTRACT FROM AUTHOR]

In this study, a transversal ultrasonic vibration-assisted riveting (TUVAR) process was developed to improve the uniformity of CFRP riveted lap joint interference-fit size, which provided a possibility for the quantization of riveted joint interference-fit sizes. The relationship between the process parameters of vibration amplitude, vibration duration, and roughness with interference-fit sizes by algorithms, through the minimum coefficient variance of interference-fit size (ICV-min) to confirm the riveting process parameters of the quantized average interference-fit sizes (IA). The experimental verification results showed that the mean absolute percentage error of measured IA and predicted IA is less than 10%. Furthermore, the tensile tests were carried out to investigate the effect of interference-fit size {1.4%, 1.6%, 1.8%, and 2.0%} on mechanical performances of CFRP riveted lap joints by TUVAR, and the tensile strength presents first-up then down with the interference-fit size increase, the maximum ultimate tensile strength is the riveted lap joint with the interference-fit size of 2.0%. Hence, the quantitative optimization method can well predict the riveting process parameters corresponding to the most uniform interference-fit size. [ABSTRACT FROM AUTHOR]

In this paper, the differences and similarities between two-layer and three-layer self-piercing riveting (SPR) joints were systematically analysed by combining experimental tests and a finite element (FE) model. The influences of top-to-middle sheet thickness ratio (r1) on the joining results of three-layer joints were also numerically investigated. It was found that, compared with the top sheet in two-layer joints, the split top and middle sheets in the corresponding three-layer joints underwent greater plastic deformation. The rivet shank experienced less plastic deformation, and the risk of shear fracture of the rivet shank was effectively reduced. When the r1 increased from 0 to infinity, the interlock (I1) always first increased then decreased and followed by an apparent increase within the studied range. The remaining bottom sheet thickness at the joint centre (tc) and under the rivet tip (ttip) showed opposite changing trends: the tc first increased and then decreased, whilst the ttip first decreased but then increased. The results also revealed that the experimental data of two-layer joints can be used to guide the design of three-layer joints: from the two-layer joints to corresponding three-layer joints, the I1 more likely achieves a greater value when the r1 < 1.0 but a smaller value when the r1 > 1.0, and a larger tc but a smaller ttip are more likely achieved regardless of the r1. [ABSTRACT FROM AUTHOR]

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Double-sided self-pierce riveting (DSSPR) can be utilized as an alternative to self-pierce riveting (SPR) to produce butt joints through half-lap joints in dissimilar materials. The mechanical joining process makes use of tubular rivets with simple geometry that are here employed to join two sheets made from aluminium (Al) and copper (Cu). This research work analyses the influence of the stainless-steel rivet on both the electrical and mechanical performance of the joint. The electrical resistance variation of the joined assembly is measured at different temperatures and compared with conventional fastened joints made from the same material combination. The mechanical performance of the aluminium–copper connections is evaluated by means of shear tests and compared to the original fastened Al-Cu joint. An experimental approach is utilized to analyse the combined influence of different mechanical and electrical parameters to assess the performance of DSSPR in electrical applications. [ABSTRACT FROM AUTHOR]

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

Self-piercing riveting (SPR) is an efficient joining process for bonding sheets through the interlock of rivet flaring. The strength of SPR joints is commonly measured by destructive test. In this study, the metal deformation behaviors in the SPR of aluminum alloy sheets and the mechanical behaviors of the SPR joints in the destructive tests were investigated in order to develop the general strength models of SPR joints. As the important feature in the SPR process, the rivet flaring was quantified by an empirical estimator and utilized to establish the general strength models considering the geometric dimensions of components and tools, the material properties of rivet and sheets, and the load–displacement curve of punch. The predicted strengths of the SPR specimens were verified by the experimental results. All the calculation errors are lower than 8%. Finally, an industrial internet of things (IIoT) was developed to realize the data processing and the SPR joint strength predication. [ABSTRACT FROM AUTHOR]

With the widespread application of lightweight materials in aerospace and automotive industries, higher demands are placed on the joining technology of lightweight materials, and the flat bottom riveting process is proposed as new technology. In this study, the material flow of three-layer sheets during the flat bottom riveting process was investigated using experimental methods. The failure modes of the sheets under different loading methods were discussed in tensile and shear tests. The results showed that a double mechanical interlock structure was created among the three-layer sheets. The first mechanical interlock between the upper and middle sheets has higher tensile and shear loads than the second mechanical interlock between the middle and lower sheets. The double mechanical interlock structure has higher joint strength compared to the single mechanical interlock structure formed by two-layer sheets of flat bottom riveting process. In addition, the tensile and shear load application methods can cause different modes of failure of the sheet. Tensile failures and pull-off failures occur with higher tensile loads and shear failures and mixed failures occur with higher shear loads. The first mechanical interlock has a stronger failure energy absorption capacity. [ABSTRACT FROM AUTHOR]

High-momentum top quarks are a natural physical system in collider experiments for testing models of new physics, and jet substructure methods are key both to exploiting their largest decay mode and to assuaging resolution difficulties as the boosted system becomes increasingly collimated in the detector. To be used in new-physics interpretation studies, it is crucial that related methods get implemented in analysis frameworks allowing for the reinterpretation of the results of the LHC such as MadAnalysis 5 and Rivet. We describe the implementation of the HEPTopTagger algorithm in these two frameworks, and we exemplify the usage of the resulting functionalities to explore the sensitivity of boosted top reconstruction performance to new physics contributions from the Standard Model Effective Field Theory. The results of this study lead to important conclusions about the implicit assumption of Standard-Model-like top quark decays in associated collider analyses, and for the prospects to constrain the Standard Model Effective Field Theory via kinematic observables built from boosted semi-leptonic t t ¯ events selected using HEPTopTagger. [ABSTRACT FROM AUTHOR]

This study focuses on the rivet early fatigue characteristics in a deep-groove ball bearing cage for a transmission system in a turboprop engine. Nonlinear dynamic differential equations for the deep-groove ball bearing with a two-piece cage were developed. The rivet stress was used to identify the early failure mechanism of the rivets. This investigation revealed that by delivering an optimal preload of the rivet causes the two halves of the cage have less misalignment and a lower rivet stress. The fit relationship between the rivet and the rivet bore has a significant influence on the rivet stress. Excessive clearance increases the stress on the head of the rivet, while excessive interference increases the stress on the middle of the rivet. For the 1.5 mm diameter rivet analyzed in this study, the appropriate fit relationship is −0.02 mm–0 mm. A reasonable matching value of the load and the speed and the cage clearance ratio are beneficial to reducing the rivet stress. The impact load acting on the bearing and a ring misalignment can increase the rivet stress. [ABSTRACT FROM AUTHOR]

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