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The majority of industries are focusing on enhancing their production processes using appropriate equipment and automation today. In both small- and large-scale enterprises, drilling, tapping, boring, and riveting are some of the most popular processes. The goal of this work is to develop and build a pneumatic drilling and riveting equipment that will reduce the labour and cycle time required for riveting. Riveting activity is currently performed physically, but with the use of pneumatics, it is possible to reduce manual power and thus semi-mechanize the activity. The traditional strategy is tedious and includes more work and cost, so there is a degree of opportunity for fostering the multipurpose machine with semi-mechanization of both drilling and riveting using pneumatics. This machine's function is to first use a drilling spindle to bore a plate of various sizes and thicknesses, and then use a rivet head to attach it. The pneumatic chamber with a cylinder, which works with the help of an air blower, which is used to run this machine. By this, the required drilling and riveting process can be accomplished. This multipurpose machine decreases the manual activities and builds efficiency with exactness, which in turn reduces machine cost, labour cost, and space involved by separate machines used earlier. [ABSTRACT FROM AUTHOR]

The rectangular hole flange channel beam is a new cold-formed steel phase that can serve as an alternative to high-connection hollow flange channel beams. This monosymmetric channel section is constructed from torsionally flexible rectangular hole flanges joined to a web plate. Numerical evaluation provides greater flexibility in selecting net and flange detail size combinations to reach optimal design capacities. Although the shear behaviour of commonly used Lipped Channel Beam (LCB) and Welded Hole Flange Beam (HFB) sections with and without net openings has been studied using finite element analysis, the crippling web capacities and failure modes of beams are affected by loading and support conditions, section profile shapes and dimensions, material properties, and hollow type, sizes, and locations. Net crippling behaviour depends on the spacing of rivets, with smaller spacing sections providing greater capacity. Equations that are conservative for numerous spacing of rivets based on the modern design equations are to be proposed for better spacing of rivets and net holes. [ABSTRACT FROM AUTHOR]

To keep up with market expectations and increase the quality and efficiency of the material processing process, technical advancements are required to keep up with the times. One of them is the use of a punch tool to link the materials together. The connecting technique was carried out in this investigation using aluminum rivets and double punch press dies. The pressing method is used to splice the material together. Aluminum tapered rivets with a length of 9 mm and a diameter of 4 mm were used. Aluminum plate from the 1100 series was used. Molds such as a half-cylindrical punch eyes mold and a flat circular punch eyes mold are used to make the connection. On each mold, the splicing is done three times at the junction. A digital microscope will be used to examine the splicing findings for changes in diameter. In the half-cylindrical punch eye mold, the diameter at riveted joint A is 5.4957 mm, and at joint B is 4.9490 mm, based on the average change in diameter. The diameter change on the flat circular punch eye mold is 4.9087 mm at Joint A and 4.7015 mm at Joint B. [ABSTRACT FROM AUTHOR]

The most common method of joining ribs and edges is riveting. In modern technology riveting process is mostly used in automotive and aerospace industry. When the bulging effects of rivets occur, there will be deformation in the material's surface structure. Riveting sequence is one important approach to eliminate continues effect of the bulging and control the deformation of the surface structure. In this investigation, sequence study of riveting process was conducted using CAD Design on 3D modeling software and finite element method in ANSYS. The materials used are Aluminum (AL1050) and SS Steel (SS310). Three ways of riveting process are done, in order to get the effective way which, last for longer period of time. In two out the three-process silicon rubber is used as adhesive. The complete study gives the ability of the riveting surface when load and various forces acting impacting the surface. It will enhance the understanding of the components assembly with riveting and help systematically improving the precision control efficiency in automotive assembly. [ABSTRACT FROM AUTHOR]

In this study, the deformation behavior of self-piercing rivets made of high-strength steel was experimentally and numerically investigated. In order to produce samples for compression testing both the head and the tip of each rivet were cut off. The remaining hollow cylinders, i.e. the shafts of the rivets, were then compressed with different jaw speeds using a Gleeble 3800 testing machine. Based on the test results the flow curves of the rivet material were determined for different strain rates. The final geometries of the deformed samples were captured using a GOM ATOS III Triple Scan measurement system. Compression testing was modeled using the finite element software Simufact FormingTM. The numerical results were validated against the experimental results using the force-displacement curves as well as the shapes of the deformed samples. Thus, the process parameters (e.g. the friction coefficient) and the material properties (e.g. the flow curve) were varied until the shapes of the deformed samples in both the simulation and the experiment were almost identical. Good agreement between the rivet shapes and between the force-displacement curves indicated the obtained flow curve to describe properly the deformation behavior of the self-piercing rivets. [ABSTRACT FROM AUTHOR]

One of the most important mechanical joining technologies for mixed-material car body constructions is self-pierce riveting with semi-tubular rivet (SPR-ST). In order to achieve appropriate joint quality for SPR-ST, it is often necessary to use individual process parameters like die geometry or rivet length for each material and thickness combination. In this paper a method is presented, that allows to increase the flexibility of the SPR-ST process by an optimization of process parameters in regard to join several material combinations with one die geometry. Thereby FEM simulation is combined with statistical approaches to develop an optimized SPR-ST process. [ABSTRACT FROM AUTHOR]

This paper shows a comparison of existing self-pierce riveting technologies with the newly developed self-pierce riveting with solid formable rivet (SPR-SF) for the joining of Aluminum die casts. The challenges during the mechanical joining of the Aluminum die cast AlSi9Mn by different joining technologies like self-pierce riveting with semi-tubular rivet (SPR-ST), self-pierce riveting with moveable die element and semi-tubular rivet (S-SPR-ST), self-pierce riveting with solid rivet (SPR-S) and self-pierce riveting with solid formable rivet (SPR-SF) will be discussed and the joining technologies in regard to process force, interlock, shear tensile strength and top tensile strength will be analyzed. [ABSTRACT FROM AUTHOR]

Drilling is a conventional machining process widely applied to carbon fiber reinforced plastics (CFRP) for the riveting and fastening purposes in the aerospace and automotive industries. However, the machining mechanism of CFRP composites differ significantly from that of homogeneous metal alloys owing to their prominent anisotropy and heterogeneity. Serious hole defects such as fiber pullout, matrix debonding and delamination are generally produced during the hole-making process, resulting in the poor machined surface quality, low fatigue durability or even the part rejections. In order to minimize the defects especially the delamination damage in composites drilling, specialized drill bits are often a primary choice being widely adopted in a real production. This paper aims to study the effects of two drills differing in geometrical characteristics during the drilling of CFRP laminates. A number of drilling experiments were carried out with the aim to evaluate the drilling performance of different drill bits. A scanning electron microscope (SEM) was used to observe the drilled surfaces to study the surface roughness. A high frequency scanning acoustic microscope (SAM) was applied to characterize the drilled hole morphologies with a particular focus on the delamination damage occurring in the CFRP laminates. The obtained results indicate that the fiber orientation relative to the cutting direction is a key factor affecting hole morphology and hole wall defects can be reduced by utilizing specialized drill geometries. Moreover, the dagger drill was confirmed outperforming the brad spur drill from the aspect of reducing drilling-induced delamination. [ABSTRACT FROM AUTHOR]

The electrical connectors mostly have silver contacts joined by riveting. In order to reduce costs, the core of the contact rivet can be replaced with cheaper material, e.g. copper. There is a wide range of commercially available bimetallic (silver-copper) rivets on the market for the production of contacts. Following that, new conditions in the riveting process are created because the bi-metal object is riveted. In the analyzed example, it is a small size object, which can be placed on the border of microforming. Based on the FEM modeling of the load process of bimetallic rivets with different material distributions, the desired distribution was chosen and the choice was justified. Possible material distributions were parameterized with two parameters referring to desirable distribution characteristics. The parameter: Coefficient of Mutual Interactions of Plastic Deformations and the method of its determination have been proposed. The parameter is determined based of two-parameter stress-strain curves and is a function of these parameters and the range of equivalent strains occurring in the analyzed process. The proposed method was used for the upsetting process of the bimetallic head of the electrical contact. A nomogram was established to predict the distribution of materials in the head of the rivet and the appropriate selection of a pair of materials to achieve the desired distribution. [ABSTRACT FROM AUTHOR]

Friction Rivecting is a quite new joining process to connect multi-material structures. In brief, a metallic rivet is dipped rotating inside matrixes, usually made of plastics, increasing its original diameter. The use of high-performance plastics is more suitable being their higher mechanical and thermal properties important to avoid material degradation and to allow strong part connections. High-speed friction welding system has been usually used to perform the process. In the work here proposed, the joints have been achieved by means of a traditional milling machine and the attention has been focused on a widely used engineering plastic, i.e. polyamide 6 (PA6) with and without glass fiber reinforcement. A specific speed multiplier has been attached into the mandrel of the used machine to increase the reachable rotational speed. Moreover, rivets made of Titanium Grade 2 and of an Aluminum Alloy, the AA-6060, are utilized. The influence that the heating and the forging length can have on the quality of the obtained junctions, considering a fixed joining depth, has been tested and investigated. The performed connections have been judged by tensile tests, which were set to quantify the maximum strength of the joints for a transverse speed of 1,0 mm/min. Barreling effect can be observed close to the tip, which loses the initial shape of a cylinder characterized by straight vertical walls. Finally, the possible degradation of the polymer, due to temperature increment, has been also evaluated close to the working zone. According to that, it has to be highlighted that the process needs a heating balance, which is necessary to get sound joints. The compromise has, on one side, to allow the rivet penetration and deformation, and on the other side, to avoid the degradation of the polymer, which would affect its properties and a proper rivet deformation. [ABSTRACT FROM AUTHOR]

Restrictions in pollutant emissions dictated at the European Commission level in the past few years have urged mass production car manufacturers to engage rapidly several strategies in order to reduce significantly the energy consumption of their vehicles. One of the most relevant taken action is light-weighting of body in white (BIW) structures, concretely visible with the increased introduction of polymer-based composite materials reinforced by carbon/glass fibers. However, the design and manufacturing of such “hybrid” structures is limiting the use of conventional assembly techniques like resistance spot welding (RSW) which are not transferable as they are for polymer-metal joining. This research aims at developing a joining technique that would eventually enable the assembly of a sheet molding compound (SMC) polyester thermoset-made component on a structure composed of several high strength steel grades. The state of the art of polymer-metal joining techniques highlighted the few ones potentially able to respond to the industrial challenge, which are: structural bonding, self-piercing riveting (SPR), direct laser joining and friction spot welding (FSpW). In this study, the promising SPR technique is investigated. Modelling of SPR process in the case of polymer-metal joining was performed through the building of a 2D axisymmetric FE model using the commercial code Abaqus CAE 6.10-1. Details of the numerical approach are presented with a particular attention to the composite sheet for which Mori-Tanaka’s homogenization method is used in order to estimate overall mechanical properties. Large deformations induced by the riveting process are enabled with the use of a mixed finite element formulation ALE (arbitrary Lagrangian-Eulerian). FE model predictions are compared with experimental data followed by a discussion. [ABSTRACT FROM AUTHOR]

A blind rivet nut is a mechanical fastener enabling a fast installation from one side. The setting process relies on plastic deformation due to axial compression of the rivet nut in such a way that a bulge is formed on the underside of the work piece. The mechanical performance of such a connection partly depends on the final geometry of the rivet nut after forming. In this contribution, the torque-to-turn resistance of an internally threaded round tubular rivet is studied with the aid of finite element techniques. A strategy is presented to simulate the setting process involving large plastic strains and contact pressures. An FE-based inverse method was used to identify the local plastic material properties of the blind rivet nut. The forming simulation was validated in terms of predicted shape of the rivet nut and the evolution of the setting force. A quasi-static FE model using the shape and solution variables of the deformed rivet nut was used to reproduce the torqueto- turn resistance as a function of the setting force. Finally, the aim is to apply the presented modelling strategy to explore innovative possibilities to increase the torque-to-turn resistance of a blind rivet nut. [ABSTRACT FROM AUTHOR]

The main scientific ingredients are recalled for developing a general finite element code and model accurately large plastic deformation of metallic materials during joining processes. Multi material contact is treated using the classical master and slave approach. Rupture may occur in joining processes or even be imposed in self piercing riveting and it must be predicted to evaluate the ultimate strength of joins. Damage is introduced with a generalized uncoupled damage criterion, or by utilizing a coupled formulation with a Lemaître law. Several joining processes are briefly analyzed in term of specific scientific issues: riveting, self piercing riveting, clinching, crimping, hemming and screwing. It is shown that not only the joining process can be successfully simulated and optimized, but also the strength of the assembly can be predicted in tension and in shearing. [ABSTRACT FROM AUTHOR]

In the present paper the influence of a higher setting velocity in the joining process of self piercing solid-rivets is shown. In the conventional process tool velocities well below 1 m/s are common. The present research results show the potential of increasing them in the range of about 5 m/s. The results are especially relevant for joining high-strength steels. These steel sheets often cause problems in the process of riveting mixed materials, e. g. aluminium-steel compound. The high strength of the steel sometimes leads to undesirable material flow in the joining process or unwanted burr development. These effects, which are described in detail in the article, can be reduced significantly for the investigated cases by the use of higher tool velocities. Using a high speed camera and a load cell, a test setup based on a drop tower was realized. It was used to time the force signals and the motion profile of the high speed riveting process. The results of the force analysis show an oscillating force progression. Within a numerical research the principal effects influencing the results of the riveting process can be shown. It was found that the pulse-like force transmission between riveting machine and punch, results in various vibrations especially of long and thin tool parts. Hence the rivet penetrates the sheet metal with non-uniform velocities. As a result the early indentation of die into the lower sheet metal at the beginning of the process is reduced, so that the final process step provides a sufficient material flow into the circular rivet groove. A strain-rate dependent process model with elastic tool properties and consideration of inertia effects is presented. [ABSTRACT FROM AUTHOR]

One way to reduce the CO2 emissions in automotives is to reduce the weight of the Body-In-White. One easy to achieve the weight reduction is to replace steel sheet materials with Al alloys, which is 3 times lighter. One issue is the joining process, especially with combinations between steel grades and AL alloys. Example of combination of mixed material combinations (Al-steel) might be found in the door structure. The reason is because of the AL alloys worthier crash performance so the automotive manufacturer might want to use crash impact beams made by high strength steels in a AL intensive door structure. The joining process between aluminum and steel are problematic due it's not possible to use traditional spot-welding technologies due to the materials total difference in microstructure characteristics as well thermal properties. To overcome this issue then mechanical as well adhesion joining are frequently used. This paper describes a development process and subsequently analysis of a self-pierce rivet (SPR) process between 3 sheet metal combinations. The multi-material combinations in this study were a combination of ultra high strength steels sheets (DP1000) and a Al-alloy (AA 6014). The analysis of the SPR process, in sense of mechanical strengths, has been done by peel- and shear tests. To reduce the amount of future physical tests a virtual FE-model has been developed for the process. This FE model of the process has been subsequently used to analyze the mechanical strength during plastic deformation. By using inverse analysis a correct contact algorithm has been evaluated that would predict the binding force between the rivet and sheet under a deformation process. With this new virtual model it will not only possible to analyze and develop the SPR process but also to achieve the final strength of the joint. [ABSTRACT FROM AUTHOR]

One of the modern industry endeavors is to be able to manufacture smaller size components using traditional or new technologies. Smaller components usually need special assembly techniques. New course of mechanical joining improvement is to develop process modification for decreased scale, i.e. micro-joining. Very interesting problems arise with self-piercing riveting (SPR) method, because one of the factors influencing SPR joint strength is rivet material properties. Rivet production by forming produces certain distribution of stress/strain field within cross-section of a rivet, influencing the process of SPR joint formation in micro-joining. Results of initial analysis of micro-joint strength are presented in the paper. Stress/strain field obtained during rivet production is taken into account in numerical simulation of micro-riveting process. Joint loading test was numerically modeled. Simulations consisted of three phases: manufacturing of the rivet, forming a joint and strength test. Stress strain fields were superimposed over the joint on every stage. Influence of the manufacturing method of the rivet on the joint quality and strength was observed. The commercial FEM software MSC-Marc is used for numerical simulations. [ABSTRACT FROM AUTHOR]

The work characterizes possible types of failure in the Self-Pierce Riveting Process. It illustrates mechanical material investigations and the simulation of fracture according to a micro-mechanical model of Rousselier. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

The Friction Stir Welding is considered to be one of the most promising processing for aeronautics. The obtained welded joints (for the best welding parameters) seem to have better resistance than conventional joining techniques including riveting. To predict the best welding process conditions, current work aims to completely describe the thermo-mechanical history using computer simulation. In this paper, we will present the latest numerical results, thermal and stress-strain fields, obtained for a “virtual” welded plate. This numerical simulation introduces both thermal and mechanical loadings using a step by step advancing coupled method with SAMCEF code. Further works are proposed for the development of a FSW predictive numerical tool. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]