A degradable mode I cohesive zone model developed for damage and fracture analysis of dissimilar composite/metal adhesive joints subjected to cyclic ageing conditions

Adhesive joints are frequently exposed to cyclic ageing conditions during their service life, which can have a substantial impact on the mechanical properties of both the adhesive and the substrates. The safe life philosophy, commonly employed in the design of bonded joints, underscores the importance of obtaining an accurate estimate of the...

Influence of cyclic aging on adhesive mode mixity in dissimilar composite/metal double cantilever beam joints

The adhesive layer in the adhesive joints can experience different modes of loading. Although the fracture energy of adhesive is generally considered to be a material parameter, it is found to be a function of the joint configuration too. Thus, to accurately simulate the behaviour of bonded joints, it is recommended to obtain the fracture...

Effect of cyclic aging on mode I fracture energy of dissimilar metal/composite DCB adhesive joints

In some industrial applications, adhesive joints are cyclically exposed to a moist environment, where cyclic moisture absorption and desorption can significantly alter the fracture energy of the bonded joints. Most previous studies are based on monotonic aging conditions, while the performance of bonded joints under cyclic aging is not well...

A review of experimental and theoretical fracture characterization of bi-material bonded joints

High performance structures require the use of different materials to meet their demanding requirements. Especially fibre reinforced polymer composites are nowadays often bonded to metals in order to take the most advantage of the materials properties and to minimize their disadvantages. However, the interface in such bi-material assemblies...

Role of adherend material on the fracture of bi-material composite bonded joints

The aim of this study is to investigate the effect of the adherend material on the mode I fracture behaviour of bi-material composite bonded joints. Both single-material (steel-steel and composite-composite) and bi-material (steel-composite) joints bonded with a structural epoxy adhesive are studied. Additionally, two adhesive bondline...

Enhanced Interface Adhesion by Novel Eco-Epoxy Adhesives Based on the Modified Tannic Acid on Al and CFRP Adherends

This paper presents a new process for obtaining eco-epoxide adhesives synthesized from bio-renewable raw material (tannic acid-TA) and used for bonding lightweight materials (aluminum (Al) and carbon fiber reinforced polymer (CFRP). Two synthesized bio-epoxy components based on TA, (A) glycidyl ether and (B) glycidyl phosphate ester of TA,...

Surface pretreatments on CFRP and titanium for manufacturing adhesively bonded bi-material joints

Adhesive bonding is a highly desirable joining technique to join composites to metals. The surfaces of both composite and metal substrates have to be carefully treated before bonding them together, in order to avoid interface failure between the adherend's surface and adhesive. This paper describes the surface pretreatments on carbon fiber...

From thin to extra-thick adhesive layer thicknesses: Fracture of bonded joints under mode I loading conditions

The fracture behaviour of joints bonded with a structural epoxy adhesive and bond line thicknesses of 0.1–4.5 mm has been studied. However, limited research is found on similar joints with thicker bond lines, which are relevant for maritime applications. Therefore, the effect of the adhesive bond line thickness, varying from 0.4 to 10.1 mm,...

The use of acoustic emission and composite peel tests to detect weak adhesion in composite structures

Adhesive bonding is one of the most promising joining technologies for composite aircraft. However, to comply with current aircraft certification rules, current safety-critical bonded joints, in which at least one of the interfaces requires additional surface preparation, are always used in combination with redundant mechanical fasteners, such...

Susceptor-assisted induction curing behaviour of a two component epoxy paste adhesive for aerospace applications

The curing behaviour and the mechanical behaviour of susceptor-assisted induction-cured adhesively bonded joints has been investigated. Induction Heating (IH) was established by mixing Iron particles into a two component epoxy paste adhesive. The effect of different process parameters, such as particle content, coupling distance and coil...

Post peel test assessment of metal-metal bonded interface using hyperspectral imaging

The adhesion process of bonded structures is a very sensitive manufacturing process, namely to surface contaminations. Nowadays, the adhesion quality of bonded joints can only be detected by destructive testing such as peel tests. But, for actual structures destructive testing of every bonded part is obviously not an option and industry is...

On the Assessment of Susceptor-Assisted Induction Curing of Adhesively Bonded Joints

The autoclave/oven curing process is known to be the current manufacturing technique that provides the best quality of composite laminates and bonded joints. However, this process implies high acquisition cost and a large ecological footprint. Furthermore, with the current complete aeroplane composite fuselages, it is infeasible to use autoclave...

On the Assessment of Susceptor-Assisted Induction Curing of Adhesively Bonded Joints