In this paper, influence of riveting process parameters, namely, riveting force, sheet thickness, friction coefficient and clearance fit are investigated on residual stress field and fatigue life of single RIVETED lap JOINT of AA2024 type. According to the effect of riveting induced residual stresses on fatigue life of RIVETED lap JOINT, these parameters are optimized to maximize the residual stress field. For this purpose, finite element simulations are performed for various combinations of the parameters according to Taguchi design of experiments. Afterwards, the parameter combination that maximize the residual stress field and the most effective parameters are obtained. The JOINT with maximum residual stress field is considered to have a semielliptical crack emanating from the rivet hole as an initial defect. Stress intensity factors are calculated by implementing two approaches: First, formulation overview that considers the effect of residual stress field, geometry and secondary bending, and second, the finite element method. The fatigue life of the JOINT is estimated using the obtained stress intensity factors and Paris-Erdogan rule. Finally, good accordance is found between results of these two approaches.

In this paper, the influencing factors on hybrid adhesive-RIVETED JOINTs were investigated. For this purpose, first a finite element model was validated based on experimental results, then the effects of influencing material and geometrical factors on the strength of the hybrid JOINTs were studied using the explicit finite element analyses. The numerical model was able to simulate damage in the adhesive layer and in the rivets. The results showed that in a hybrid adhesive-RIVETED JOINT, it is better to position the rivets where a minimum reduction in the adhesive JOINT due to the rivet holes obtained i.e. as far as possible from the JOINT ends. This is in contrary to the RIVETED JOINTs in which placing the rivets closer to the JOINT ends resulted higher JOINT strength. In general, incorporating rivets in an adhesive JOINT for manufacturing a hybrid JOINT can result higher or lower JOINT strength in comparison with the adhesive JOINT in different conditions that were studied in this research. It should be noted that in case that a low-strength adhesive is utilized in a hybrid adhesive-RIVETED JOINT then placing the rivets closer to the JOINT ends can results higher strength for the JOINT similar to the RIVETED JOINTs.

Till now, various models have been proposed in literature to simulate the behavior of RIVETED structures. In order to find the most accurate analytical method in modeling the dynamic behavior of RIVETED structures, a comparison study is performed on several of these models, in this research. For this purpose, experimental modal analysis tests are conducted on a RIVETED plate to verify the efficacy of the analytical models. Moreover, finite element model updating is used to reduce the difference between analytical and experimental results. First, the material properties of plates are optimized using the experimental results obtained from modal tests of a simple plate. Next, the optimization is performed for the physical properties of rivet. At the end, it is concluded that the fastener model proposed by Rutman can bring about the most accurate results when it is used in combination with solid plates and gap elements in the contact region.

In this paper, experimental investigation was performed to estimate fatigue life of single and double RIVETED coach peel JOINTs of 2024 aluminum alloy. Load controlled fatigue tests were conducted with load ratio and frequency of 0. 1 and 10 Hz, respectively. Failure of the specimens revealed three major modes of folded region fracture (A-type), fracture from edge of the rivet hole (B-type) and mixed mode fracture (A & B). Although all failure modes contributes equally in single RIVETED JOINT, mixed mode fracture was observed as dominant mode in two RIVETED ones. A numerical approach is applied to estimate fatigue life of RIVETED coach peel JOINTs. Finite element analysis was implemented by ABAQUS as the first step of this approach to estimate stress distribution, stress concentration factor, stress and strain amplitude. Fatigue lives were then calculated using three fatigue life theories of Monson-Hirschberg, Smith-Watson-Topper and Morrow. Finally, good accordance between numerical and experimental results revealed that the finite element approach combined with fatigue life theories is capable for fatigue life prediction. It is concluded that adding a rivet in longitudinal direction to the single RIVETED coach peel JOINT decreases the life cycles by increasing the stress concentration factor. Moreover, results of finite element approach showed that Monson-Hirschberg and experimental data has the best agreement in compare with SWT and Morrow.

In aeronautical and automotive industries the use of rivets for applications requiring several joining points is now very common. In spite of a very simple shape, a RIVETED junction has many contact surfaces and stress concentrations that make the local stiffness very difficult to be calculated. To overcome this difficulty, commonly finite element models with very dense meshes are performed for single JOINT analysis because the accuracy is crucial for a correct structural analysis. Anyhow, when several RIVETED JOINTs are present, the simulation becomes computationally too heavy and usually significant restrictions to JOINT modelling are introduced, sacrificing the accuracy of local stiffness evaluation. In this paper, we tested the accuracy of a rivet finite element presented in previous works by the authors. The structural behaviour of a lap JOINT specimen with a rivet joining is simulated numerically and compared to experimental measurements. The Rivet Element, based on a closed-form solution of a reference theoretical model of the rivet JOINT, simulates local and overall stiffness of the junction combining high accuracy with low degrees of freedom contribution. In this paper the Rivet Element performances are compared to that of a FE non-linear model of the rivet, built with solid elements and dense mesh, and to experimental data. The promising results reported allow to consider the Rivet Element able to simulate, with a great accuracy, actual structures with several rivet connections.

In this research, with the aim of investigating the effect of temperature on the performance of adhesive, RIVETED and composite glass/epoxy JOINTs, the factors affecting this JOINT are studied. After checking the parameters, preparing the surface of the connection area using sandpaper on two levels using sandpaper with grain numbers of 220 and 400 and also controlling the thickness of the adhesive layer on two levels of 0. 13 and 0. 26 mm. The meter and the type of drill used to make holes on both surfaces were selected using a saw drill and a wood drill for rivet connection. The integration of selected parameters of two adhesive and RIVETED JOINTs is considered in order to investigate the combined JOINT. In this regard, the experimental design using the Taguchi method has been carried out in the Minitab test design software. The purpose of conducting the experimental part of this research, as mentioned in the previous lines, is to obtain optimal JOINTs according to the defined parameters and levels in order to set a standard and compare with the values obtained after performing the test on the mentioned JOINTs under the effect of 80 It is the degree Celsius applied to the samples for four hours. In order to bring the results closer to the industrial conditions, we connected a number of adhesive, RIVETED and combined samples using the optimal levels of parameters defined for each of them, based on the zigzag arrangement of four rivets along the width of the area, which

Alarm systems are essential in safe operation of industrial plants. Since many process variables are interacting with each other, so in this paper, an approximate method is introduced to design and analysis of a multivariate alarm system. In this method, the alarm system is designed base on JOINT indices. The JOINT FAR and JOINT MAR are defined for a m-variable alarm system thanks to multivariate Markov scheme. In proposed method, the alarm JOINT indices are defined by solving a Linear Programing (LP) optimization problem. By defining JOINT indices, tuning of the alarm parameters (like, threshold and etc. ) can be done by these indices instead of correlation analysis. In this paper, penalty scenario and Genetic algorithm are used for alarm generation, and parameter optimization in Tennessee Eastman (TE) Process. The results of proposed method are compared with other methods.