DYNAMIC PERFORMANCE OF ADHESIVELY BONDED SINGLE LAP JOINTS WITH DIFFERENT FIBER ANGLE ORIENTATIONS OF ADHERENDS

2021 ◽  
Author(s):  
S. BUSE KARAAHMET ◽  
FERHAT KADIOGLU
Keyword(s):  
Adhesive Bonding ◽  
Flexural Rigidity ◽  
Dynamic Performance ◽  
Adhesive Layer ◽  
Lap Joints ◽  
Adhesive Film ◽  
Single Lap Joints ◽  
Vibration Technique ◽  
Materials Used ◽  
Fixed End

This work aims to investigate the dynamic response of the adhesive bonding of Single Lap Joints (SLJs) using a free vibration technique. For this purpose, the joints with fixed-end conditions were subjected to the vibration test, and the results were compared with the numerical ones which were obtained from the Finite Element Method (FEM) via the ANSYS package program. The materials used in this study are an adhesive film, AF163 2K produced by 3M, and adherends, manufactured from a glass reinforced polymer matrix composite, produced by Hexcel. While four different adherends with different fiber orientations were used, the thickness of the adhesive layer in bonded region was kept constant, 0.2 mm. In doing so, the main concentration was given to the adherends as the energy dissipation was believed to come mainly from them. The main objective was to get high damping values without compromising any decrease in the structural performance of the joints. The experimental natural frequency, flexural rigidity and damping values of the joints were obtained as a parameter of the different adherend types. The results were also validated using numerical modal analysis.

Experimental and Analytical Investigations of the Dynamic Response of Adhesively Bonded Single Lap Joints

2004 ◽  
Vol 126 (1) ◽  
pp. 84-91 ◽  
Author(s):  
A. Vaziri ◽  
H. Nayeb-Hashemi ◽  
H. R. Hamidzadeh
Keyword(s):  
Dynamic Response ◽  
Loss Factor ◽  
Natural Frequencies ◽  
Adhesive Layer ◽  
Lap Joints ◽  
Laser Vibrometer ◽  
Total System ◽  
Adhesive Film ◽  
Single Lap Joints ◽  
Central Void

Dynamic response of single lap joints, subjected to a harmonic peeling load is studied theoretically and experimentally. In the theoretical part, dynamic response of a single lap joint clamped at one end and subjected to a harmonic peeling load at the other end is investigated. Adherents are modeled as Euler-Bernouli beams joined in the lap area by a viscoelastic adhesive layer. Both axial and transverse deformations of adherents are considered in deriving the equations of motion. The effects of adhesive layer thickness, mechanical properties and its loss factor on the dynamic response of the joint are investigated. Furthermore, effects of defects such as a void in the lap area on the dynamic response of the joints are studied. The results showed that frequencies where peak amplitudes occurred were little dependent on the adhesive loss factor. However, peak amplitudes reduced for joints with a higher adhesive loss factor. Furthermore, the results indicated that for the joint geometries and properties investigated the system resonant frequencies were not affected by the presence of a central void covering up to 80% of the overlap length. In the experimental part, single lap joints were fabricated using 6061-T6 Aluminum. Adherents were joined together using Hysol EA 9689 adhesive film. Joints with various central voids were manufactured by removing adhesive film from the desired area of lap joints prior to bonding adherents. Dynamic responses of the joints were investigated using the hammer test technique. The system response was measured using both an accelerometer and a noncontact laser vibrometer. The natural frequencies of the joints obtained by using the laser vibrometer were very close to those obtained theoretically. However, natural frequencies obtained by using an accelerometer depended on the accelerometer location in the system, which was attributed to its mass contribution to the over- all system mass. A central void covering less than 80% of the overlap length had little effect on the system resonance frequencies. This was in agreement with the theoretical results. In contrast total system-damping ratios were a function of the void size. Joints without a void exhibited higher damping.

Experimental and Analytical Investigations of the Dynamic Response of Adhesively Bonded Single Lap Joints

2002 ◽  
Author(s):  
A. Vaziri ◽  
H. Nayeb-Hashemi
Keyword(s):  
Dynamic Response ◽  
Loss Factor ◽  
Natural Frequencies ◽  
Adhesive Layer ◽  
Lap Joints ◽  
Laser Vibrometer ◽  
Total System ◽  
Adhesive Film ◽  
Single Lap Joints ◽  
Central Void

Dynamic response of single lap joints, subjected to a harmonic peeling load is studied theoretically and experimentally. In the theoretical part, dynamic response of a single lap joint clamped at one end and subjected to a harmonic peeling load at the other end is investigated. Adherents are modeled as Euler-Bernouli beams joined in the lap area by a viscoelastic adhesive layer. Both axial and transverse deformations of adherents are considered in deriving the equations of motion. The effects of adhesive layer thickness, mechanical properties and its loss factor on the dynamic response of the joint are investigated. Furthermore, effects of defects such as a void in the lap area on the dynamic response of the joints are studied. The results showed that frequencies where peak amplitudes occurred were little dependent on the adhesive loss factor. However, peak amplitudes reduced for joints with a higher adhesive loss factor. Furthermore, the results indicated that for the joint geometries and properties investigated the system resonant frequencies were not affected by the presence of a central void covering up to 80% of the overlap length. In the experimental part, single lap joints were fabricated using 6061-T6 Aluminum. Adherents were joined together using Hysol EA 9689 adhesive film. Joints with various central voids were manufacture by removing adhesive film from the desired area of lap joints prior to bonding adherents. Dynamic responses of the joints were investigated using the hammer test technique. The system response was measured using both an accelerometer and a non-contact laser vibrometer. The natural frequencies of the joints obtained by using the laser vibrometer were very close to those obtained theoretically. However, natural frequencies obtained by using an accelerometer depended on the accelerometer location in the system, which was attributed to its mass contribution to the over all system mass. A central void covering less than 80% of the overlap length had little effect on the system resonance frequencies. This was in agreement with the theoretical results. In contrast, total system-damping ratios were a function of the void size. Joints without a void exhibited higher damping.

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.

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.

scholarly journals Experimental and Numerical Study of Low-Velocity Impact and Tensile after Impact for CFRP Laminates Single-Lap Joints Adhesively Bonded Structure

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1016
Author(s):  
Chunxing Hu ◽  
Guibin Huang ◽  
Cheng Li
Keyword(s):  
Lap Joints ◽  
Low Velocity Impact ◽  
Adhesively Bonded ◽  
Low Velocity ◽  
Adhesive Film ◽  
Velocity Impact ◽  
Cfrp Laminates ◽  
Single Lap Joints ◽  
Impact Energies ◽  
The Impact

To investigate the mechanical behavior of the single-lap joints (SLJs) adhesively bonded structure of carbon fiber reinforced polymer (CFRP) laminates under the low-velocity impact (LVI) and tensile-after impact (TAI), tests and simulations were carried out. A finite element model (FEM) was established based on the cohesive zone model (CZM) and Hashin criterion to predict the damage evolution process of adhesive film, intra- and inter-laminar of the SLJs of CFRP laminates, and its effectiveness was verified by experiments. Moreover, three different overlap lengths (20 mm, 30 mm, and 40 mm) and four different impact energies (Intact joint, 10 J, 20 J, and 30 J) are considered in the present study. Finally, the effects of different impact energies and overlap lengths on the residual strength of SLJs after impact were discussed. The results divulged that numerical results of impact and TAI processes of SLJs were in good agreement with experiment results. During the impact process, the damage of the laminates was primarily fiber and matrix tensile damage, whereas the adhesive film was damaged cohesively; the areas of damage increased with the increase of impact energy, and the normal stress of the adhesive film expanded from the edge to the middle region with the increase of impact force. The influence of LVI on SLJs adhesively bonded structures was very significant, and it is not effective to obtain a higher impact resistance by increasing the overlap length. For the tensile process, the failure mode of TAI of the SLJs was interface failure, the surplus strength of the SLJs gradually decreased with the increase of the impact energy because of the smaller overlap length, the overlap length more than 30 mm, and the low energy impact has almost no effect on the residual strength of the SLJs.

Damage investigation on the adhesively bonded single-lap joints of three-dimensional braided composite and laminates

2017 ◽  
Vol 36 (10) ◽  
pp. 725-738 ◽  
Author(s):  
Xiao-Kang Li ◽  
Zhen-Guo Liu ◽  
YuChen Wei ◽  
Xiang Huang ◽  
Bing Lei
Keyword(s):  
Composite Structures ◽  
High Performance ◽  
Adhesive Bonding ◽  
Failure Process ◽  
Three Dimensional ◽  
Lap Joints ◽  
Tensile Failure ◽  
Failure Behavior ◽  
Braided Composite ◽  
Single Lap Joints

Adhesive bonding is usually used to fabricate composite structures that are hard to manufacture in one piece, however, their lightweight advantage is usually impaired by low failure strength. For high performance composite structures, bonding properties of joints dominate the failure performance and commonly are the primary target of structural optimization. Both experimental and numerical studies of failure behavior of single-lap joints with three-dimensional braided composite laminate adherends are presented in this paper. First, tensile failure tests were performed on braid-laminates single-lap joints bonded with epoxy resin. Compared with the laminates–laminates single-lap joints, the failure load of the braid–laminates single-lap joints increased by 18.4%. Then, the Finite Element Method (FEM) coupled with cohesive zone models (CZM), considering different value of overlap length (L), was used to perform the detail stress distribution of the overlap sections of SLJs. Further, damage initialization and crack growth of single-lap joints are analyzed in detail to fully characterize the failure process, and both experimental and numerical results lead to the same conclusion. Lastly, the effect of three-dimensional braided adherends’ braiding angle on braid-laminates single-lap joints’ performance was investigated, which provides suggestions for the design and optimization for adhesive bonded composite structures.

scholarly journals Development of hybrid friction stir welding and adhesive bonding single lap joints in aluminium alloys

2019 ◽  
Vol 13 (48) ◽  
pp. 269-285 ◽  
Author(s):  
Ricardo Maciel ◽  
Virginia Infante ◽  
Daniel Braga ◽  
Pedro Moreira ◽  
Tiago Bento ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Aluminium Alloys ◽  
Adhesive Bonding ◽  
Lap Joints ◽  
Friction Stir ◽  
Single Lap Joints

scholarly journals Non-linear methods based on ultrasonic waves to analyse disbonds in single lap joints

2017 ◽  
Vol 231 (16) ◽  
pp. 3066-3076 ◽  
Author(s):  
G Scarselli ◽  
F Ciampa ◽  
F Nicassio ◽  
M Meo
Keyword(s):  
Adhesive Layer ◽  
Lap Joints ◽  
Ultrasonic Waves ◽  
Destructive Testing ◽  
Linear Elastic ◽  
Single Lap Joints ◽  
Non Linear ◽  
Structural Responses ◽  
Non Destructive

Adhesive bonded lap joints are widely used in the aerospace field and non-destructive testing (NDT) techniques are critical in evaluating the quality of adhesion before and during use. Two types of bonded samples have been experimentally investigated in order to verify the reliability of non-linear elastic wave spectroscopy (NEWS) based on the use of ultrasound. Piezoelectric sensors have been attached to the samples and used as generators and receivers. Both the samples have shown non-linearities in their dynamic behaviour. Non-linear metrics have been applied to their structural responses over an assigned range of excitation frequencies based on higher order harmonic analysis in order to evaluate the degree of non-linearity of the samples. Possible interpretations of the experimental behaviour are provided in the paper based also on tomographic testing of the adhesive layer that showed the presence of microbubbles in the bond due to manufacturing process.

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