Allowable Load Assessment in Metal-Composite Double-Lap Joint / Avaliação de Carga Permitida em Junta de Dupla Folga Metal-Composto

2021 ◽  
Vol 7 (8) ◽  
pp. 82563-82575
Author(s):  
Helio de Assis Pegado ◽  
Rafael Felipe De Souza ◽  
Rodrigo de Sa´ Martins
Keyword(s):  
Load Distribution ◽  
Safety Margin ◽  
Metal Composite ◽  
Allowable Stress ◽  
Lap Joint ◽  
The Finite Element Method ◽  
Double Shear ◽  
Metal Metal ◽  
Riveted Joint ◽  
Allowable Load

This work consists of evaluating the tensile and compression static allowable stress of a hybrid (metal-composite) riveted joint. The analyzed joint is composed by two sheets of 2014 – T6 aluminium alloy and a T300/5208 Graphite/Epoxy quasi-isotropic laminate, which were joined by twelve Lockbolt Swaged Collar rivets titanium alloy Ti–6Al–4V annealed. The joint was analyzed through a computational model developed using the Finite Element Method (FEM), with the fasteners modelled through the Multi - Springs technique. This method was widely used to simulate the mechanical behaviour metal-metal and composite-composite parts of the joint. It is validated comparing its results with analytical results of metallic joints available in the literature. Through this model, both the allowable load and its distribution in the fasteners of the joint were determined. Since the evaluated joint is subjected to double shear and, therefore, has no eccentricities, the presence of secondary bending was not observed, the bearing and bypass loads were the most relevant in evaluating the allowable loads of the joint. The load distribution in the joint and its components’ safety margin was determined, with the laminate being the limiting component of the allowable load.

Composite Solutions for Deck Catamarans

2018 ◽  
Vol 55 (1) ◽  
pp. 1-4
Author(s):  
Elena Felicia Beznea ◽  
Ionel Chirica ◽  
Adrian Presura ◽  
Ionel Iacob
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Sandwich Structure ◽  
High Strength ◽  
Total Weight ◽  
External Loading ◽  
Strength Analysis ◽  
Allowable Stress ◽  
The Finite Element Method ◽  
Inland Navigation

The paper is treating the strength analysis of the main deck structure of an inland navigation catamaran for 30 passengers. The main deck should have high stiffness and high strength to resist to external loading and endure high stresses from combined bending and torsion loads. Different materials for sandwich structure of the deck have been analysed by using the Finite Element Method in order to determine the solution which accomplish better designing criteria regarding allowable stress and deformations and total weight.

Crack propagation behavior of inhomogeneous laminated Ti−Nb metal−metal composite

2019 ◽  
Vol 29 (9) ◽  
pp. 1882-1888 ◽  
Author(s):  
Wen-juan CHENG ◽  
Yong LIU ◽  
Da-peng ZHAO ◽  
Bin LIU ◽  
Yan-ni TAN ◽  
...  
Keyword(s):  
Crack Propagation ◽  
Metal Composite ◽  
Propagation Behavior ◽  
Metal Metal ◽  
Crack Propagation Behavior

scholarly journals Stability charts based on the finite element method for underground cavities in soft carbonate rocks: validation through case-study applications

2019 ◽  
Vol 19 (10) ◽  
pp. 2079-2095 ◽  
Author(s):  
Michele Perrotti ◽  
Piernicola Lollino ◽  
Nunzio Luciano Fazio ◽  
Mario Parise
Keyword(s):  
Finite Element ◽  
Safety Margin ◽  
Structural Elements ◽  
The Finite Element Method ◽  
Geometrical Features ◽  
Overall Stability ◽  
Underground Cavities ◽  
The Stability ◽  
Rock Mechanical Properties

Abstract. The stability of man-made underground cavities in soft rocks interacting with overlying structures and infrastructures represents a challenging problem to be faced. Based upon the results of a large number of parametric two-dimensional (2-D) finite-element analyses of ideal cases of underground cavities, accounting for the variability both cave geometrical features and rock mechanical properties, specific charts have been recently proposed in the literature to assess at a preliminary stage the stability of the cavities. The purpose of the present paper is to validate the efficacy of the stability charts through the application to several case studies of underground cavities, considering both quarries collapsed in the past and quarries still stable. The stability graphs proposed by Perrotti et al. (2018) can be useful to evaluate, in a preliminary way, a safety margin for cavities that have not reached failure and to detect indications of predisposition to local or general instability phenomena. Alternatively, for sinkholes that already occurred, the graphs may be useful in identifying the conditions that led to the collapse, highlighting the importance of some structural elements (as pillars and internal walls) on the overall stability of the quarry system.

Control of Grasp Stability in Humans Under Different Frictional Conditions During Multidigit Manipulation

1999 ◽  
Vol 82 (5) ◽  
pp. 2393-2405 ◽  
Author(s):  
Magnus K. O. Burstedt ◽  
J. Randall Flanagan ◽  
Roland S. Johansson
Keyword(s):  
Load Distribution ◽  
Safety Margin ◽  
Middle Finger ◽  
The Other ◽  
Surface Material ◽  
Tangential Load ◽  
Normal Forces ◽  
Grasp Stability ◽  
Contact Surfaces ◽  
Lift Off

Control of grasp stability under different frictional conditions has primarily been studied in manipulatory tasks involving two digits only. Recently we found that many of the principles for control of forces originally demonstrated for two-digit grasping also apply to various three-digit grasps. Here we examine the control of grasp stability in a multidigit task in which subjects used the tips of the thumb, index, and middle finger to lift an object. The grasp resembled those used when lifting a cylindrical object from above. The digits either all contacted the same surface material or one of the digits contacted a surface material that was more, or less, slippery than that contacted by the other two digits. The three-dimensional forces and torques applied by each digit and the contact positions were measured along with the position and orientation of the object. The distribution of forces among the digits strongly reflected constraints imposed by the geometric relationship between the object's center of mass and the contact surfaces. On top of this distribution, we observed changes in force coordination related to changes in the combination of surface materials. When all digits contacted the same surface material, the ratio between the normal force and tangential load ( F n: L ratio) was similar across digits and scaled to provide an adequate safety margin against slip. With different contact surfaces subjects adapted the F n: L ratios at the individual digits to the local friction with only small influences by the friction at the other two digits. They accomplished this by scaling the normal forces similarly at all digits and changing the distribution of load among the digits. The surface combination did not, however, influence digit position, tangential torque, or object tilting systematically. The change in load distribution, rather, resulted from interplay between these factors, and the nature of this interplay varied between trials. That is, subjects achieved grasp stability with various combinations of fingertip actions and appeared to exploit the many degrees of freedom offered by the multidigit grasp. The results extend previous findings based on two-digit tasks to multidigit tasks by showing that subjects adjust fingertip forces at each digit to the local friction. Moreover, our findings suggest that subjects adapted the load distribution to the current frictional condition by regulating the normal forces to allow slips to occur early in the lift task, prior to object lift-off.

Determination of the Creep Deflection of a Rivet in Double Shear

1959 ◽  
Vol 26 (2) ◽  
pp. 285-290
Author(s):  
Joseph Marin
Keyword(s):  
Theoretical Prediction ◽  
Power Plants ◽  
Elevated Temperatures ◽  
Structural Components ◽  
Double Shear ◽  
Riveted Joints ◽  
Simple Tension ◽  
Riveted Joint ◽  
Jet Power

Abstract Structural components of modern aircraft are subjected to elevated temperatures by jet power plants and by skin friction resulting from supersonic speeds. Some of these high-temperature-aircraft structural components are riveted connections. Considerable experimental data are available on the creep of riveted connections used in aircraft [1]. However, a survey of the literature shows a lack of results on the theoretical prediction of creep in riveted connections from the usual creep and creep-rupture data for simple tension. The creep of a riveted joint is dependent on various factors including rivet diameter, rivet lengths, and plate thicknesses. This influence of size means that each particular riveted joint must be tested to obtain the necessary information. A basic approach to the problem is theoretically to predict the creep behavior of riveted joints from creep in simple tension. One of the important parts of the creep deformation of a riveted connection, Fig. 1(a), is the creep of the rivet. This paper deals with an approximate theoretical prediction of the creep deflection in a rivet based upon the creep constants of the material in simple tension.

A Finite-Element and Experimental Analysis of Stress Distribution in Various Shear Tests for Solder Joints

1998 ◽  
Vol 120 (1) ◽  
pp. 106-113 ◽  
Author(s):  
T. Reinikainen ◽  
M. Poech ◽  
M. Krumm ◽  
J. Kivilahti
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Low Cycle Fatigue ◽  
Material Model ◽  
Lap Joints ◽  
Optical Measurements ◽  
Nonlinear Material ◽  
Lap Joint ◽  
The Finite Element Method ◽  
Shear Tests

Solder alloys are commonly tested with shear tests to study their mechanical properties or low-cycle fatigue performance. In this work, the suitability of various shear tests for quantitative solder-joint testing is investigated by means of the finite element method. The stress state and stress distribution in the following well known geometries are studied: the double-lap test, the ring and plug test, the losipescu test, and two single-lap tests. A new test geometry, the grooved-lap test, is introduced and compared to the conventional tests. The results of simulations with an elastic material model in plane-strain indicate that considerable differences in the purity of the state of shear (rε = −ε1/ε3) as well as in the stress distribution in the joint exist among the shear tests. However, simulations with a nonlinear material model show that stress inhomogenities are smoothed by the plastic and creep deformation occurring in the joint. Optical measurements of the deformation of real single-lap and grooved-lap joints show that the single-lap joint rotates slightly during creep, whereas in the grooved-lap joint no rotation can be detected. This confirms the simulation results that in the single-lap test the initially nonuniform stress distribution changes during creep, and in the grooved-lap test the uniform stress distribution remains constant through the test.

Modeling Ionic Polymer-Metal Composites with Space-Time Adaptive Multimeshhp-FEM

2012 ◽  
Vol 11 (1) ◽  
pp. 249-270 ◽  
Author(s):  
David Pugal ◽  
Pavel Solin ◽  
Kwang J. Kim ◽  
Alvo Aabloo
Keyword(s):  
Coupled System ◽  
Metal Composite ◽  
Ionic Polymer Metal Composite ◽  
The Finite Element Method ◽  
Metal Composites ◽  
Ionic Polymer Metal Composites ◽  
Ionic Polymer ◽  
Qualitative And Quantitative ◽  
Polymer Metal ◽  
Adaptive Fem

AbstractWe are concerned with a model of ionic polymer-metal composite (IPMC) materials that consists of a coupled system of the Poisson and Nernst-Planck equations, discretized by means of the finite element method (FEM). We show that due to the transient character of the problem it is efficient to use adaptive algorithms that are capable of changing the mesh dynamically in time. We also show that due to large qualitative and quantitative differences between the two solution components, it is efficient to approximate them on different meshes using a novel adaptive multimeshhp-FEM. The study is accompanied with numerous computations and comparisons of the adaptive multimeshhp-FEM with several other adaptive FEM algorithms.

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