Papers by Keyword: Riveting

Abstract: Riveting is the most important method for joining two sheets of different materials. In order to promote electromagnetic pulse riveting (EMR), the influence of the impact velocity will be studied in this paper in order to correctly model the electromagnetic field of the riveting process. There are many parameters associated to the riveting process, however, the interference fit is considered as the most important criterion to measure the riveting quality, which consequently will be associated to the impact velocity, being this the most important parameter. The use of the washer will be studied to guarantee the optimal flow of the material and to restrict the expansion of the rivet shaft, thus minimizing damage to the composite material. The interference generated between the rivet shaft and the hole of the sheets and the flow of the material will be developed by finite elements which will later be validated by means of experimental tests analyzing its final microstructure. Finally, the relationship between the impact velocity on the rivet head will be directly related to the distribution of the interference generated in the deformation, verifying that the impact velocity.

Abstract: Among various composites available for use, carbon fiber reinforced composite is unique in its Nature. Carbon fiber is an extremely strong thin fiber made by pyrolyzing synthetic fibers, such as rayon, until charred. High Strength Composites are made from this fiber by using appropriate matrix material mostly Epoxy resins are used. High Strength, stiffness, light weight and high thermal conductivity are the main advantages over the other composites. Making products with one single composite sheet is not possible always. Some of the intricate or complex shape making is required for joining of two composite sheet. The composites joining can be done in three ways mainly Adhesive, Riveting and Hybrid. Based on the Review among all these joints adhesive joining gives better economic solution in joining. Experimental results point to significant influence of fibre on mechanical properties of sample. The tensile test of the acoustic signal emission (AE) to identify the current state of material integrity in real time. Acoustic system signal correlated to damage events. The carbon fiber composite characteristic failure mechanisms are initiated on the microscale and result in a spontaneous release of elastic energy in terms of mechanical stress waves, the so-called acoustic emissions.

Abstract: The paper presents new techniques for joining of materials, proposed for development by ISIM Timisoara. It shows the general considerations and preliminary results regarding two new methods of joining by riveting, methods based on friction processes: - a joining process by riveting with hybrid effect, that means mechanical grip - friction stir welding - a joining process by friction riveting. Experiments for joining by riveting were carried out for couples of metallic materials (rivet and base materials) similar and dissimilar (aluminum alloys, steel, copper). There are presented conditions and requirements for the joining processes, how to form the riveted joint, positive results and limits of the application. Primary technical data on process principle, data on technological parameters, rivet configuration and influence factors were obtained.

Abstract: Upsetting and extruding riveting is a new joining method, which is mainly used to join castings. In order to investigate the effect of geometric dimensions of punch and upper sheet hole diameter on the quality of joints, models with different geometric parameters were simulated via ABAQUS. According to the simulation results, the riveting process could be divided into five stages. Besides, diameter difference on rivet tail and interference value on upper sheet hole wall were selected as indicators to evaluate quality of joints. And a group of parameters is obtained for a better quality of joints. Finally, the simulation results were validated through experiments.

Abstract: In order to help department to make a decision whether the equipment need maintenance, some people trained the sample of characteristic parameter for riveting structure, and set up the model to recognize target by computer vision. However, we are difficult to find the research result about the affiliation between the characteristic parameter of the riveting structure and the model. In this paper, we make the image processing first, and use SVM (Support Vector Machines) algorithm to train the sample of characteristic parameter for rivet head. Finally, we research the affiliation between the characteristic parameter for the rivet head and the mathematical model, and test the accuracy of the model.

Abstract: In the course of ongoing development of riveting technologies, various methods were developed in the last years. Riveting is one of the most important joining methods. Nowadays, pre-hole riveting methods have been widely used in aviation, automobile and other fields because of its advantages of simple joining process, low cost and light weight. This paper mainly presents several typical pre-hole riveting methods. Their technical characteristics, working principles and research status are introduced. Also, this paper proposes the limitations and future focuses of typical pre-hole riveting methods.

Abstract: This paper introduces the elements, production, development, strongpoints and application of electromagnetic riveting. It analyses the effect of different length of rivet on the connection. The transmutation of rivet is well proportioned. As the length increases, the symmetry of rivet decreases. This paper compares pneumatic riveting and electromagnetic riveting, and expatiate the strongpoints of electromagnetic riveting, such as one time forming, easy to control, symmetrical transmutation, low undulation, steady connecting quality, easy to rivet. Finally, this paper summaries the electromagnetic riveting technology and calls attention to it.

Abstract: A novel integrated heating and riveting control system for TB2 titanium alloy rivet based on the precise heating temperature and the heating time control is designed in this paper. The novel heating and riveting control system is implemented by using a linear current sensor to measure primary side current of output transformer of the control system so as to determine heating temperature, and using a microcontroller to precisely control heating time. Comparing to the difficult heating temperature control of the traditional rivet heating system of which heating time is controlled by time relay, our novel control system has implemented precise heating temperature control by precise heating time control and heating current control. The experimental results show the heating time error of rivet heater of this research is less than 0.1 second, and the novel control system is more reliable, convenient and accuracy than that traditional one controlled by time relay. The actual production results show required riveting temperature can be attained accurately under the condition of working voltage even with ±10% fluctuation, and the novel control system brings to increase the rate of finished products of riveted TB2 titanium alloy rivet about 15%.

Abstract: The riveting joint is the main connection to fasten two thin-walled sheet-metal parts in aircraft assembly. As one of important parameters in riveting process, the riveting force is mostly determined by the experience and experiments in actual production, lack of theoretical basis supported. This paper researched the maximum allowed value of riveting force in the elastic deformation stage of riveting process. Based on the theory of compression instability, the mathematics model of relationship among rivets diameter, rivet holes diameter and maximum riveting force was built. Then, by using the software for finite element analysis-ABAQUS, the instance of riveting process simulation was made. Finally, the result of instances simulation was compared with the mathematics model. The comparison shows that the mathematics model based on the theory of compression instability is effective and correct.

Abstract: The riveting joint is the main connection method in aircraft assembly. There are some kind of rivets, such as slug rivet and protruding rivet, that riveting quality will be impacted while rivets axis are not coincident with the plate holes axis. By using the finite element method with ABAQUS software, this paper built the 3D riveting joint structure of finite element, and analyzed the axis deviation effect on the deformation, stress and strain of riveting. Through statistical data, the relationship among axis deviation value, deformation, stress and strain of rivet are built.