Stress analysis of adhesively-bonded single stepped-lap joints based on three-parameter fractional viscoelastic foundation model

2021 ◽  
pp. 146442072110624
Author(s):  
Mehdi Veisytabar ◽  
Arash Reza ◽  
Younes Shekari
Keyword(s):  
Differential Equations ◽  
Viscoelastic Model ◽  
Viscoelastic Behavior ◽  
Adhesive Layer ◽  
Lap Joints ◽  
Inverse Laplace Transform ◽  
Viscoelastic Foundation ◽  
Adhesively Bonded ◽  
Transform Method ◽  
The Time Domain

This paper aims to develop a viscoelastic analytical model for adhesively bonded single stepped-lap joints subjected to tensile loading. The adherends are aluminum alloy A6063 and modeled as Timoshenko elastic beams and the adhesive is epoxy type B. A three-parameter fractional viscoelastic foundation (3PFVF) model is proposed to express the governing stresses in the joint and the fractional Zener model is used to model the viscoelastic behavior of the adhesive layer. The proposed 3PFVF model makes it possible to have different peel stresses between the two interfaces of adhesive and adherends. The governing differential equations are derived in the Laplace domain, and then solved and transformed simultaneously in the time domain using the Gaver-Stehfest inverse Laplace transform method. The finite element simulation with ANSYS is applied to validate the proposed method. The results show that a simple fractional viscoelastic model, which has a short differential equation, offers the same results as the classical viscoelastic models, which have higher and more complex differential equations. Moreover, the results show that the maximum shear and peel stresses in the single stepped-lap joints are about 20% less than single-lap joints.

Three-Dimensional Viscoelastic Interactions of a Center of Dilatation with a Penny-Shaped Interfacial Crack

2011 ◽  
Vol 117-119 ◽  
pp. 471-475 ◽  
Author(s):  
Yu Zhou Sun ◽  
Ya Dong Bian ◽  
Zhong Guo Zhang
Keyword(s):  
Rock Fracture ◽  
Auxiliary Problem ◽  
Viscoelastic Model ◽  
Three Dimensional ◽  
Interfacial Crack ◽  
Viscoelastic Behavior ◽  
Inverse Laplace Transform ◽  
Bimaterial Interface ◽  
Thermal Dilatation ◽  
The Time Domain

This paper presents a three-dimensional viscoelastic model to study the interactions of a penny-shaped interfacial crack and a center of dilatation in the infinite viscoelastic bimaterial, which can model the rock fracture subjected to stress and thermal dilatation during some engineering process. A distinct issue associated with the present work is the incorporation of viscoelastic behavior of bimaterial. The proposed problem is first transformed into the Laplace space, and the solution in the transform space is obtained by decomposing the original problem into two auxiliary problems: (I) a center of dilatation near a bimaterial interface (no crack); and (II) a penny-shaped interfacial crack subject to internal tractions that cancel out those induced in auxiliary problem (I). The mode I, II and III stress intensity factors (SIFs) in the time domain are obtained with the inverse Laplace transform.

scholarly journals Compression Shear Properties of Adhesively Bonded Single-Lap Joints of C/C Composite Materials at High Temperatures

Symmetry ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1437 ◽  
Author(s):  
Yanfeng Zhang ◽  
Zhengong Zhou ◽  
Zhiyong Tan
Keyword(s):  
Composite Materials ◽  
Adhesive Layer ◽  
Lap Joints ◽  
Experimental Result ◽  
Shear Stresses ◽  
Test Results ◽  
Adhesively Bonded ◽  
Finite Element Software ◽  
Joint Structure ◽  
Simulation Results

The performance of joint structure is an important aspect of composite material design. In this study, we examined the compression shear bearing capacity of the adhesively bonded single-lap joint structure of high-temperature-resistant composite materials (C/C composite materials). The test pieces were produced in accordance with the appropriate ASTM C1292 standard, which were used for the compression shear test. The failure morphology of the layer was observed by a digital microscopic system and scanning electron microscope. The experimental result shows that the load on the test piece increased nonlinearly until the failure occurred, and most of the adhesive layer exhibited cohesive failures at three temperature points (400, 600, and 800 °C), while the interface failures occurred in a small part of the adhesive layer. A numerical analysis model was established using ABAQUS finite element software. The simulation results were compared with the test results to verify the correctness of the model. On the basis of correctness of the model verified by comparing the simulation results and the test results, the influences of temperature and overlapped length on the joint compression shear performance were studied through the validated simulation method. Numerical results showed that the ultimate load of the joint decreased with increases in temperature and that the distribution trends of the shear stresses in the overlapped length direction were substantially the same for joints of different overlapped lengths.

Simplified stiffness analysis for degraded single lap joints in the space sector – Comparative analytical and finite element analysis

2020 ◽  
Vol 234 (13) ◽  
pp. 1956-1966
Author(s):  
Jannik Zimmermann ◽  
Josef Weiland ◽  
Mohammad Zamaan Sadeghi ◽  
Alexander Schiebahn ◽  
Uwe Reisgen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Ionizing Radiation ◽  
Coefficient Of Thermal Expansion ◽  
Closed Form Solution ◽  
Adhesive Layer ◽  
Lap Joints ◽  
Polymer Chains ◽  
Adhesively Bonded ◽  
European Organization

Considering the aerospace sector, the use of adhesively bonded joints is constantly increasing over the last decades. Due to its lightweight and capability of joining various materials with different coefficient of thermal expansion, this joining technique offers many benefits over conventional methods like rivets, screws and welding. On the other hand, structural adhesives consists of polymer chains that can be severely affected by the environment. An example of such an environmental effect is the interaction of the polymer chains of the adhesive with ionizing radiation in space. Nevertheless in the literature, the influence of ionizing radiation on the mechanical properties of epoxides is covered but not well understood. The present work describes a method of determining the stiffness of an adhesively bonded single lap joint (SLJ) using closed form solution equations. This analytical approach is compared with a numerical model. The mechanical properties of the adhesive in both models is degraded due to irradiation, based on experiments conducted by the European Organization for Nuclear Research (CERN). The results show that the degradation of the mechanical properties of the adhesive layer has a significant influence on the joint stiffness. This effect increases with growing adhesive layer thickness. Comparing the results with a finite element model, it is shown that the developed calculation scheme overestimates the stiffness of the SLJ. This is caused by the neglection of bending stresses within the adherends.

MECHANICAL BEHAVIOR OF ADHESIVELY-BONDED JOINTS UNDER HIGH LOADING RATES

2021 ◽  
Author(s):  
MEHMET EMIN ERCAN ◽  
FERHAT KADIOGLU
Keyword(s):  
Adhesive Layer ◽  
Experimental Tests ◽  
Lap Joints ◽  
Adhesively Bonded ◽  
Case Scenario ◽  
Worst Case ◽  
Adhesive Film ◽  
Package Program ◽  
Set Up ◽  
Static Conditions

This work aims to investigate the dynamic behavior of adhesively-bonded Single Lap Joints (SLJs) under ballistic conditions. For this purpose, the joints with clamped-clamped boundary conditions were modelled using a Finite Element Method (FEM) via ABAQUS package program. The numerical model is based on the joint subjected to a projectile with a mass of 1.25 gr, a density of 11.3 gr/cm3, and an impacting velocity of 100 m/s. The experimental tests conducted in a specially designed set-up were performed via an air-pressurized gun. 6061 aluminum adherends and an adhesive film were used to manufacture the bonded structure. Curves of the velocity and dynamic load against time were predicted for the joint under the impacting projectile. Failure and stress distributions in the adherend as well as in the adhesive layer were predicted that was validated via the experimental results. The prediction was made according to the worst case scenario that accounts the input data obtained from the quasi-static conditions.

Viscoelastic Analysis of Adhesively Bonded Double – Lap Joint

2007 ◽  
Vol 345-346 ◽  
pp. 1473-1476
Author(s):  
Sang Soon Lee
Keyword(s):  
Room Temperature ◽  
Viscoelastic Model ◽  
Tensile Load ◽  
Adhesive Layer ◽  
Lap Joint ◽  
Epoxy System ◽  
Adhesively Bonded ◽  
Viscoelastic Analysis ◽  
Edge Cracks ◽  
Local Yielding

In this paper, stress distribution in a double lap joint subjected to a tensile load is investigated using the boundary element method. The adhesive used in this study is a commercial epoxy system which can be cured at room temperature. The adhesive is assumed to be linearly viscoelastic. The order of the singularity is obtained numerically for a given viscoelastic model. The numerical results show that interface stresses are large enough to initiate local yielding or edge cracks. Since the exceedingly large stresses cannot be borne by the adhesive layer, edge cracks can occur at the interface corner.

Acoustic Emission on Adhesively Bonded Single-Lap Joints of Composite Laminate during Tensile Test

2014 ◽  
Vol 912-914 ◽  
pp. 441-444
Author(s):  
Yan Rong Pang ◽  
Ran Liu ◽  
Ya Juan Li ◽  
Bo Han Lu ◽  
Xin Kang Xing ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Tensile Test ◽  
Composite Laminate ◽  
Mechanical Response ◽  
Adhesive Layer ◽  
Relative Energy ◽  
Lap Joints ◽  
Adhesively Bonded ◽  
Damage And Failure ◽  
Single Lap Joints

Acoustic emission (AE) was used to monitor the tensile test of composites with adhesive specimens. The mechanical response behavior, damage and failure characteristics, and the corresponding AE characteristics of the composites have been investigated. The results show that the load of the join with defect in the adhesive layer is lower than the join with no defect. The higher AE relative energy and the AE amplitude were obtained in the adhesive specimen with defect in the adhesive layer whereas the variation of the AE relative energy is different from the adhesive specimen with on defect. The characteristics such as AE amplitude distribution, relative energy and cumulative hits are connected with the tensile damage and failure of the adhesively bonded single-lap joints of composite laminate. In the actual AE monitoring, these feature parameters should be considered entirely assess the damage and failure of the composites structures.

A Coupled Peel and Shear Stress-Diffusion Model for Adhesively Bonded Single Lap Joints

2017 ◽  
Vol 139 (9) ◽  
Author(s):  
Emad Mazhari ◽  
Sayed A. Nassar
Keyword(s):  
Shear Stress ◽  
Diffusion Model ◽  
Adhesive Layer ◽  
Lap Joints ◽  
Fickian Diffusion ◽  
Lap Joint ◽  
Adhesively Bonded ◽  
Single Lap Joints ◽  
Single Lap Joint ◽  
Stress Diffusion

In this study, the Fickian diffusion formulation is extended to the adhesive layer of a single lap joint (SLJ) model, in order to develop a coupled peel and shear stress-diffusion model. Constitutive equations are formulated for shear and peel stresses in terms of adhesive material properties that are time- and location-dependent. Numerical solution is provided for the effect of diffusion on shear and peel stresses distribution. Detailed discussion of the results is presented.

Viscoelastic Analysis of Adhesive Bonded Lap Joints Between Tubes Under Torsion

1988 ◽  
Vol 110 (3) ◽  
pp. 384-388 ◽  
Author(s):  
Gianluca Medri
Keyword(s):  
Shear Stress ◽  
Steady State ◽  
Structural Analysis ◽  
Viscoelastic Model ◽  
Adhesive Layer ◽  
Lap Joints ◽  
Viscoelastic Analysis ◽  
Linear Viscoelastic ◽  
Analytical Relations ◽  
Linear Viscoelastic Model

In this paper a structural analysis of cemented lap joints between tubes under torsion is presented. The behavior of the joints has been evaluated using a linear viscoelastic model of the adhesive layer and for both steady state and general loading conditions. Analytical relations for the shear stress in the adhesive layer for the torsional compliance of the joints are proposed.

A Coupled Shear Stress-Diffusion Model for Adhesively Bonded Single Lap Joints

2016 ◽  
Vol 83 (10) ◽  
Author(s):  
Sayed A. Nassar ◽  
Emad Mazhari
Keyword(s):  
Shear Stress ◽  
Diffusion Model ◽  
Adhesive Layer ◽  
Lap Joints ◽  
Fickian Diffusion ◽  
Equilibrium Equations ◽  
Adhesively Bonded ◽  
Adhesive Material ◽  
Single Lap Joints ◽  
Stress Diffusion

In this study, a coupled shear stress-diffusion model is developed for the analysis of adhesively bonded single lap joints (SLJs) by applying Fickian diffusion model to the adhesive layer. Differential equations of equilibrium are formulated in terms of adhesive material properties that are time and location dependent. By invoking a Volkersen approach on the equilibrium equations, a shear stress differential equation is formulated and numerically solved. Several scenarios are considered for investigating the effect of diffusion on shear stress distribution in adhesively bonded SLJs. Detailed discussion of the results is presented.

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