Non-linear analysis and optimization of adhesively bonded single lap joints between fibre-reinforced plastics and metals

doi:10.1016/0143-7496(94)90039-6

International Journal of Adhesion and Adhesives

Volume 14, Issue 4, October 1994, Pages 261-267

https://doi.org/10.1016/0143-7496(94)90039-6 Get rights and content

Abstract

Non-linear finite element methods are applied in the analysis of single lap joints between fibre-reinforced plastics (FRP) and metals. The importance of allowing for both geometric and material non-linearities is shown. The optimization of single lap joints is done by modifying the geometry of the joint ends. Different shapes of adhesive fillet, reverse tapering of the adherend, rounded edges and denting are applied in order to increase the joint strength. The influence of the joint-end geometry is shown for different metal adherend/FRP adherend/adhesive combinations. The results of the numerical predictions suggest that with a careful joint-end design the strength of the joints can be increased by 90–150%.

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An experimental and simulation study of RGO effects on mechanical behaviour of structural adhesive and lap shear joints strength
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This research explores the effects of various local geometrical modifications on failure characteristics of single lap joint via an experimental study. The study was coupled with a numerical investigation by using a commercially available finite element software Abaqus®. Aerospace-grade aluminum alloy 6061-T6 was used as adherends in the fabrication of lap joints. The adherends were bonded with Araldite® 2011 structural adhesive. Geometric techniques ranging from the external taper, internal taper, adherend rounding, adhesive fillets, and a combination of internal taper with adhesive fillet were examined. Each geometric configuration was evaluated experimentally and numerically using a parametric methodology. The best-performing parameter of each geometric configuration was then compared with the others for the reduction in adhesive stresses and failure load. The geometric configuration of internal taper with adhesive fillet showed the highest reduction in both peel and shear stresses of 88.58% and 39%, respectively, which was subsequently reflected by the maximum improvement in failure load of 60.29% when compared to the base geometry without any modification.
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Citation Excerpt :
Consequently, several investigations have been carried out to study their effects and their dependency on joint strength. Most of the strength optimization studies are parametric in nature, where the variable of interest is varied over a selected range using predefined intervals [10–14]. Non-parametric techniques rely on predefined algorithms that maximize and minimize the variable of interest under applied constraints [15].
In this research, the combined effects of Multi-Walled Carbon Nanotubes (MWCNTs) addition, functionalization, and filler concentration on mechanical properties of high viscous structural adhesive and strength characteristics of adhesively bonded joints were experimentally investigated. Two configurations of lap joints: single lap joint (SLJ) and double lap strap joint (DLSJ) were manufactured with Araldite 2011 adhesive. Aluminum alloy 5083 was used as adherends in the fabrication of the lap joints. Non-functionalized, carboxylate (COOH), and amine (NH₂) functionalized MWCNTs were added in amounts of 0.25, 0.5, 0.75, and 1 wt% in the host resin. Solution mixing technique was used for mixing of MWCNTs in the host resin. The prepared adhesive was then used to make bulk adhesive samples and lap joints. The strength properties of epoxy adhesive and lap shear joints were determined by tensile testing of the specimens. For adhesive, a maximum reduction of 54% in elastic modulus and 23% in tensile strength was observed with the addition of 1 wt% functionalized MWCNT_COOH. The decrease in strength was inversely related to failure strain, consequently increasing the toughness characteristics of the adhesive. The lap joints showed a significant improvement in joint strength with the added MWCNTs. A maximum improvement of 60% for SLJ and 31% for DLSJ was observed with the addition of 1 wt% non-functionalized MWCNTs. ANOVA study was performed for the evaluation of data variation and interaction. Optical and Scanning Electron Microscopy (SEM) was utilized for the analysis of fracture surfaces, and the correlation between nano-reinforcement and strengthening mechanisms was critically discussed.

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Non-linear analysis and optimization of adhesively bonded single lap joints between fibre-reinforced plastics and metals

Abstract

Int. J. Adhes. Adhes.

Int. J. Adhes. Adhes.

J. Adhes.