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.

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.

scholarly journals Ultrasonic Welding of Magnetic Hybrid Material Systems – 316L Stainless Steel to Ni/Cu/Ni-Coated Nd2Fe14B Magnets

2020 ◽  
Author(s):  
Moritz Liesegang ◽  
Tilmann Beck
Keyword(s):  
Shear Strength ◽  
Magnetic Flux ◽  
Hybrid Material ◽  
Permanent Magnets ◽  
Ultrasonic Welding ◽  
Bonded Joints ◽  
Adhesively Bonded ◽  
Adhesively Bonded Joints ◽  
Magnetic Devices ◽  
Material Systems

Abstract The performance of electric sensors is continuously improving due to the demands of modern vehicles and electronic devices. Magnetic sensors are used in a wide field of applications. However, handling and mounting the typical high-performance rare earth permanent magnets are challenging due to their brittleness. A constant magnetic flux is a key property of the magnetic setup in many devices. State-of-the-art adhesive bonding of magnets in devices can cause problems due to the low durability and viscous behaviour of adhesive polymers, as the magnet may change its position and hence, the magnetic flux distribution in the magnetic setup changes.Ultrasonic welding is a powerful technique to join hybrid material systems quickly and reliably, providing high joint strength, even for brittle materials such as glasses, ceramics and rare earth permanent magnets. The latter is being investigated in this work for the first time. The ultrasonic welding process was adapted to join 316L stainless steel, representing potential components of magnetic devices, to Ni/Cu/Ni-coated Nd2Fe14B. In addition to directly joined steel/magnet-hybrids, ductile aluminium and nickel interlayers were used in order to enhance the joint strength. Process parameters were developed and evaluated considering the resulting shear strength of the joints. The highest shear strength of 35 MPa was achieved for 316L/Nd2Fe14B and 316L/Al/Nd2Fe14B, which is more than twice the shear strength of adhesively bonded joints of up to 20 MPa, according to the literature. The functional performance of the hybrid material systems, evaluated by the magnetic flux density of the hybrid material systems was the highest for directly bonded joints, and those with a nickel interlayer, which did not show any losses in comparison to the single magnet in its initial state. Joints with an aluminium interlayer showed losses of 3% and adhesively bonded joints showed losses of 7% of the magnetic flux density.In summary, the results of this work indicate that ultrasonic welding is a suitable technique to improve the production process and performance of magnetic devices.

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.

Temperature Effect on the Shear Strength of Adhesively Bonded Joints

2013 ◽  
Vol 758 ◽  
pp. 119-124 ◽  
Author(s):  
Kenji R. Osanai ◽  
João M.L. Reis
Keyword(s):  
Shear Strength ◽  
Strength Loss ◽  
Work Conditions ◽  
Epoxy Adhesive ◽  
Lap Joints ◽  
Bonded Joints ◽  
Adhesively Bonded ◽  
Adhesively Bonded Joints ◽  
Single Lap Joints ◽  
Made In

The purpose of this paper is to study some of the factors that affect the shear strength of Single Lap Joints (SLJ). Based in work conditions for different applications, tests were made in order to define the influence of geometry and temperature on the strength of SLJ under shear load. The adhesive used to make the joints was the epoxy adhesive ARC858 and it was tested under temperatures ranging between 21°C and 70°C and overlap length of 12.5mm and 18.75mm. Results of those tests showed that shear strength increased due to geometry with an overlap of 18.75mm and a great shear strength loss ranging from 30°C to 50°C. The failure mechanism was adhesive failure.

Influence of Roughness and Curing Temperature on the Strength of Aluminum Adhesively Bonded Joints

2021 ◽  
Vol 883 ◽  
pp. 227-233
Author(s):  
Giovanna Rotella ◽  
Maria Rosaria Saffioti ◽  
Michela Sanguedolce ◽  
Luigino Filice
Keyword(s):  
Surface Roughness ◽  
Lap Joints ◽  
Curing Temperature ◽  
Bonded Joints ◽  
Adhesively Bonded ◽  
Adhesively Bonded Joints ◽  
Curing Conditions ◽  
Single Lap Joints ◽  
Roughened Surface ◽  
Indentation Tests

This work presents a comprehensive experimental study on the effect of surface roughness and adhesive curing temperature on adhesively bonded joints of AA6082. The modification of surface morphology has been assessed by roughness measurements (contact and non-contact profilometry). In addition, mechanical changes in the resin properties due to different curing time have been probed through a series of instrumented indentation tests. Thus, adhesive bonded single lap joints were fabricated and tested to assess the changes in shear strength at varying surface roughness and curing conditions. The obtained results indicate the ability of the roughened surface to improve the joint strength together with the adequate combination of curing temperature and time among those suggested by the manufacturer.

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 Ultrasonic welding of magnetic hybrid material systems –316L stainless steel to Ni/Cu/Ni-coated Nd2Fe14B magnets

2021 ◽  
Author(s):  
Moritz Liesegang ◽  
Tilmann Beck
Keyword(s):  
Shear Strength ◽  
Magnetic Flux ◽  
Hybrid Material ◽  
Permanent Magnets ◽  
Ultrasonic Welding ◽  
Bonded Joints ◽  
Adhesively Bonded ◽  
Adhesively Bonded Joints ◽  
Magnetic Devices ◽  
Material Systems

Abstract The performance of electric sensors is continuously improving due to the demands of modern vehicles and electronic devices. Magnetic sensors are used in a wide field of applications. However, handling and mounting the typical high-performance rare earth permanent magnets are challenging due to their brittleness. A constant magnetic flux is a key property of the magnetic setup in many devices. State-of-the-art adhesive bonding of magnets in devices can cause problems due to the low durability and viscous behaviour of adhesive polymers, as the magnet may change its position and hence, the magnetic flux distribution in the magnetic setup changes.Ultrasonic welding is a powerful technique to join hybrid material systems quickly and reliably, providing high joint strength, even for brittle materials such as glasses, ceramics and rare earth permanent magnets. The latter is being investigated in this work for the first time. The ultrasonic welding process was adapted to join 316L stainless steel, representing potential components of magnetic devices, to Ni/Cu/Ni-coated Nd2Fe14B. In addition to directly joined steel/magnet-hybrids, ductile aluminium and nickel interlayers were used in order to enhance the joint strength.Process parameters were developed and evaluated considering the resulting shear strength of the joints. The highest shear strength of 35 MPa was achieved for 316L/Nd2Fe14B and 316L/Al/Nd2Fe14B, which is more than twice the shear strength of adhesively bonded joints of up to 20 MPa, according to the literature. The functional performance of the hybrid material systems, evaluated by the magnetic flux density of the hybrid material systems was the highest for directly bonded joints, and those with a nickel interlayer, which did not show any losses in comparison to the single magnet in its initial state. Joints with an aluminium interlayer showed losses of 3% and adhesively bonded joints showed losses of 7% of the magnetic flux density.In summary, the results of this work indicate that ultrasonic welding is a suitable technique to improve the production process and performance of magnetic devices.

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