Experimental Study of Dynamic Behaviour of Aluminum/Aluminum and Composite/Composite Double Lap Joints

2011 ◽  
Vol 62 ◽  
pp. 155-163 ◽  
Author(s):  
O. Essersi ◽  
Mostapha Tarfaoui ◽  
S. Boyd ◽  
R.A. Shenoi ◽  
F. Meraghni
Keyword(s):  
Adhesive Bonding ◽  
Dynamic Behaviour ◽  
Lap Joints ◽  
High Rate ◽  
Bonded Joints ◽  
Adhesively Bonded ◽  
Adhesively Bonded Joints ◽  
Loading Rates ◽  
Structural Adhesive ◽  
Force Displacement

This paper presents an experimental investigation on the behaviour of structural adhesive bonding under quasi-static and moderately high loading rates. It addresses the effects of the loading rate on the strength of the adhesively bonded joints under dynamic tensile. A comparison has been achieved between the strength and the damage of specimens’ made of aluminium and lamina substrates. High rate tests showed ringing in the force/displacement curves.

scholarly journals Defects and uncertainties of adhesively bonded composite joints

2021 ◽  
Vol 3 (9) ◽  
Author(s):  
Sadik Omairey ◽  
Nithin Jayasree ◽  
Mihalis Kazilas
Keyword(s):  
Composite Materials ◽  
Composite Structures ◽  
Production Efficiency ◽  
Adhesive Bonding ◽  
Detection Methods ◽  
Bonded Joints ◽  
Adhesively Bonded ◽  
Adhesively Bonded Joints ◽  
Wide Range ◽  
Bonded Composite

AbstractThe increasing use of fibre reinforced polymer composite materials in a wide range of applications increases the use of similar and dissimilar joints. Traditional joining methods such as welding, mechanical fastening and riveting are challenging in composites due to their material properties, heterogeneous nature, and layup configuration. Adhesive bonding allows flexibility in materials selection and offers improved production efficiency from product design and manufacture to final assembly, enabling cost reduction. However, the performance of adhesively bonded composite structures cannot be fully verified by inspection and testing due to the unforeseen nature of defects and manufacturing uncertainties presented in this joining method. These uncertainties can manifest as kissing bonds, porosity and voids in the adhesive. As a result, the use of adhesively bonded joints is often constrained by conservative certification requirements, limiting the potential of composite materials in weight reduction, cost-saving, and performance. There is a need to identify these uncertainties and understand their effect when designing these adhesively bonded joints. This article aims to report and categorise these uncertainties, offering the reader a reliable and inclusive source to conduct further research, such as the development of probabilistic reliability-based design optimisation, sensitivity analysis, defect detection methods and process development.

Experimental study of the out-of-plane dynamic behaviour of adhesively bonded composite joints using split Hopkinson pressure bars

2018 ◽  
Vol 52 (21) ◽  
pp. 2875-2885 ◽  
Author(s):  
S Sassi ◽  
M Tarfaoui ◽  
H Benyahia
Keyword(s):  
Strain Rate ◽  
Dynamic Behaviour ◽  
Dynamic Compression ◽  
Strain Rates ◽  
Bonded Joints ◽  
Adhesively Bonded ◽  
Adhesively Bonded Joints ◽  
Out Of Plane ◽  
Bonded Composite ◽  
Strong Material

The effect of the strain rate on the mechanical behavior and the damage of adhesively bonded joints is one of the most important factors to consider in designing them. Vast research has been carried out on the dynamic behaviour of adhesives at different strain rates; however, the investigation about the dynamic behaviour of the adhesively bonded joints is limited. In this paper, the main objective is to study and assess the effect of the strain rate on the out-of-plane mechanical behaviour of adhesively bonded joints under dynamic compression using Hopkinson bars. These joints are studied using glass/vinylester composite materials which are commonly used in naval applications. The experimantal results have shown a strong material sensitivity to strain rates. Moreover, damage investigations have revealed that the failure mainly occurred in the adhesive/adherent interface because of the brittle nature of the polymeric adhesive. Results have shown good agreement with the dependency of the dynamic parameters on strain rates.

Effect of aluminium substrate thickness on the lap-shear strength of adhesively bonded and hybrid riveted-bonded joints

2020 ◽  
pp. 095440892091343
Author(s):  
VC Beber ◽  
N Wolter ◽  
B Schneider ◽  
K Koschek
Keyword(s):  
Shear Strength ◽  
Failure Process ◽  
Lap Joints ◽  
Substrate Thickness ◽  
Bonded Joints ◽  
Adhesively Bonded ◽  
Lap Shear Strength ◽  
Lap Shear ◽  
Definition Of ◽  
Structural Adhesive

For lightweight materials, e.g. aluminium, the definition of proper joining technology relies on material properties, as well as design and manufacturing aspects. Substrate thickness is especially relevant due to its impact on the weight of components. The present work compares the performance of adhesively bonded (AJ) to hybrid riveted-bonded joints (HJ) using aluminium substrates. To assess the lightweight potential of these joining methods, the effect of substrate thickness (2 and 3 mm) on the lap-shear strength (LSS) of single lap joints is investigated. An epoxy-based structural adhesive is employed for bonding, whilst HJs are produced by lockbolt rivet insertion into fully cured adhesive joints. The stiffness of joints increased with an increase of substrate thickness. HJs presented two-staged failure process with an increase in energy absorption and displacement at break. For HJs, the substrate thickness changed the failure mechanism of rivets: with thicker substrates failure occurred due to shear, whereas in thinner substrates due to rivet pulling-through. The LSS of 2 mm and 3 mm-thick AJs is similar. With 2 mm-thick substrates, the LSS of HJs was lower than AJs. In contrast, the highest LSS is obtained by the 3 mm-thick HJs. The highest lightweight potential, i.e. LSS divided by weight, is achieved by the 2 mm-thick AJs, followed by the 3 mm-thick HJs with a loss of ca. 10% of specific LSS.

Experimental analysis of adhesively bonded joints in synthetic- and natural fibre-reinforced polymer composites

2019 ◽  
Vol 54 (9) ◽  
pp. 1245-1255 ◽  
Author(s):  
HFM de Queiroz ◽  
MD Banea ◽  
DKK Cavalcanti
Keyword(s):  
Polymer Composites ◽  
Automotive Industry ◽  
Natural Fibre ◽  
Lap Joints ◽  
Bonded Joints ◽  
Adhesively Bonded ◽  
Adhesively Bonded Joints ◽  
Reinforced Polymer ◽  
Fibre Composites ◽  
Fibre Reinforced Polymer

The application of adhesively bonded joints in automotive industry has increased significantly in recent years mainly because of the potential for lighter weight vehicles, fuel savings and reduced emissions. The use of composites in making automotive body components to achieve a reduced vehicle mass has also continuously increased. Natural fibre composites have recently attracted a great deal of attention by the automotive industry due to their many attractive benefits (e.g. high strength-to-weight ratio, sustainable characteristics and low cost). However, the literature on natural fibre-reinforced polymer composite adhesive joints is scarce and needs further investigation. The main objective of this study was to evaluate and compare the mechanical performance of adhesively bonded joints made of synthetic- and natural fibre-reinforced polymer composites. Similar and dissimilar single lap joints bonded with a modern tough structural adhesive used in the automotive industry, as well as the epoxy resin AR260 (the same resin used in composite fabrication) were tested. It was found that the average failure loads varied significantly with adhesive material strength and adherend stiffness. Furthermore, it was also observed that failure mode has a significant effect in failure load. The jute-based natural fibre composites joints, both hybrid and purely natural, were superior in strength compared to the sisal-based natural composites joints.

Integrity monitoring of adhesively bonded joints via an electromechanical impedance-based approach

2017 ◽  
Vol 17 (5) ◽  
pp. 1031-1045 ◽  
Author(s):  
Yitao Zhuang ◽  
Fotis Kopsaftopoulos ◽  
Roberto Dugnani ◽  
Fu-Kuo Chang
Keyword(s):  
Fatigue Loading ◽  
Mechanical Tests ◽  
Lap Joints ◽  
Piezoelectric Sensors ◽  
Bonded Joints ◽  
Adhesively Bonded ◽  
Monitoring Method ◽  
Integrity Monitoring ◽  
Adhesively Bonded Joints ◽  
Electromechanical Impedance

Monitoring the bondline integrity of adhesively bonded joints is one of the most critical concerns in the design of aircraft structures to date. Due to the lack of confidence on the integrity of the bondline both during fabrication and service, the industry standards and regulations require assembling the primary airframe structure using the inefficient “black-aluminum” approach, that is, drill holes and use fasteners. Furthermore, state-of-the-art non-destructive evaluation and structural health monitoring approaches are not yet able to provide mature solutions on the issue of bondline integrity monitoring. Therefore, the objective of this work is the introduction and feasibility investigation of a novel bondline integrity monitoring method that is based on the use of piezoelectric sensors embedded inside adhesively bonded joints in order to provide an early detection of bondline degradation. The proposed approach incorporates (1) micro-sensors embedded inside the adhesive layer leaving a minimal footprint on the material, (2) numerical and analytical modeling of the electromechanical impedance of the adhesive bondline, and (3) electromechanical impedance–based diagnostic algorithms for monitoring and assessing the bondline integrity. The experimental validation and assessment of the proposed approach is achieved via the design and fabrication of prototype adhesively bonded lap joints with embedded piezoelectric sensors and a series of mechanical tests under various static and dynamic (fatigue) loading conditions. The obtained results demonstrate the potential of the proposed approach in providing increased confidence on the use of adhesively bonded joints for aerospace structures.

Studying Effects of Arc Discharge Surface Texturing on Stress Distribution in Adhesively Bonded Joints by Using Finite Element Modeling

2011 ◽  
Author(s):  
Mehdi Asgharifar ◽  
Fanrong Kong ◽  
Blair Carlson ◽  
Radovan Kovacevic
Keyword(s):  
Stress Distribution ◽  
Adhesive Bonding ◽  
Arc Discharge ◽  
Treatment Method ◽  
Bonded Joints ◽  
Textured Surfaces ◽  
Adhesively Bonded ◽  
Adhesively Bonded Joints ◽  
Optical Profilometer ◽  
Adhesively Bonded Joint

This study investigates the potentiality of using atmospheric-pressure Direct Current (DC) plasma arc discharge as a surface treatment method of aluminum alloys in adhesively bonded joints in order to enhance adhesion. The surface morphology exposed to the arc for the current of 40 A (low intensity) and the plasma torch scanning speeds between 20 and 120 mm/s, exhibits a micro-scale surface roughness appropriate for adhesive bonding. The arc textured surfaces are characterized by using an optical profilometer. Additionally, the effect of modified surface on the stress distribution throughout the single-lap adhesively bonded joint in tension is explored by 2D FEM. The geometrical model for FE analysis of adhesively bonded structure is generated by including the surface texture coordinates obtained from the optical profilometer.

Analysis of Adhesively Bonded Joints Between Panels of Composite Materials

1977 ◽  
Vol 44 (1) ◽  
pp. 101-106 ◽  
Author(s):  
W. J. Renton ◽  
J. R. Vinson
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Orthotropic Material ◽  
Structural Response ◽  
Lap Joints ◽  
Bonded Joints ◽  
Excellent Correlation ◽  
Adhesively Bonded ◽  
Adhesively Bonded Joints ◽  
Material Systems

A mathematical model is developed and methods of analysis are formulated for determining the structural response of the single-lap and symmetric-lap joints composed of generally orthotropic material systems. Analytical results are compared in both instances with experimental data and excellent correlation is seen to exist.

The Effects of Inherent Flaws on the Time and Rate Dependent Failure of Adhesively Bonded Joints

1982 ◽  
Vol 104 (3) ◽  
pp. 643-650 ◽  
Author(s):  
E. Sancaktar ◽  
S. Padgilwar
Keyword(s):  
Lap Joints ◽  
Bonded Joints ◽  
Adhesively Bonded ◽  
Concentration Effects ◽  
Adhesively Bonded Joints ◽  
Single Lap Joints ◽  
Creep Stress ◽  
Rate Dependent ◽  
Dependent Failure ◽  
Creep Loading

Experiments on single lap joints bonded with viscoelastic adhesives reveal that the effects of rate and time and inherent flaws are as critical in joint failure as are the environmental and stress concentration effects. Experimental data reveal that random inherent flaws and loading rate changes may result in as much as 40 percent reduction in joint strength. Furthermore when creep loading is used, the asymptotic creep stress, below which no delayed failure will occur, may have to be as much as 45 percent less than the adhesive maximum strength.

Effect of Adhesive Layer’s Voids on Stress Distribution of Adhesively Bonded Joints

2010 ◽  
Vol 139-141 ◽  
pp. 986-989 ◽  
Author(s):  
Hai Long Zhao ◽  
Zong Zhan Gao ◽  
Zhu Feng Yue ◽  
Zhi Feng Jiang
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Stress Distribution ◽  
Adhesive Layer ◽  
Shear Loading ◽  
Lap Joints ◽  
Bonded Joints ◽  
Adhesively Bonded ◽  
Adhesively Bonded Joints ◽  
Single Lap Joints

The stress distribution of adhesively-bonded single lap joints under tensile shear loading is analyzed using 2-dimensional elastic-plastic finite element method (FEM). Special attentions have been put on the influence of void in adhesive on the stress distribution of adhesively-bonded joints. The results show that the stress concentration of the void is less than that of the end part of the joints when adhesive layer’s deformation was in the range of elastic. Moreover, the influence of the void on the stress distribution becomes less when the void moving from the end-part to the middle. The stress concentration becomes larger and the stress distribution of adhesive’s mid-thickness region becomes flatter when adhesive layer has biggish plastic deformation. Finite element results show an agreement with the theoretical results.

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