Analysis Of Single Lap Joint Research Articles

Strength Analysis in Bonded, Bolted and Bolted-Bonded Joints, Single Lap Joints, Metal/Composite Plates

Today, especially in many fields that require structural durability, such as the aerospace and automotive industries, there has been a need to use different bonding techniques separately or together in order to use materials together with different mechanical properties. In this study, stress and damage analysis of single lap joints, bonding and bolt-bonding metal/composite joints under tensile loads were performed. The nine kinds of single lap joint models in different combinations (bonded, bolted and bolt-bonded) were prepared by using acrylic adhesive (Acrytron 1E1) and 100-25-3 mm in size; AZ91/AZ91, AZ91-carbon fiber and carbon fiber-carbon fiber plates. Some comparisons were carried out by examining the stresses and deformations that occur in joint models exposed to tensile and 4-point bending tests. As a result of the tensile test, it was determined that the highest maximum tensile stress occurred in AZ91-CF bolt-bonded samples. In the four-point bending test, the maximum shear force value was determined in the CF-CF bolted-bonded samples.

Stress Analysis of Single Lap Joint Using Al 6063 and GFRP as Adherents with Bond 108 as Adhesive

Stress Analysis of Single Lap Joint Using Al 6063 and GFRP as Adherents with Bond 108 as Adhesive

Single and dual adhesive bond strength analysis of single lap joint between dissimilar adherends

The emerging trends for joining of aircraft structural parts made up of different materials are essential for structural optimization. Adhesively bonded joints are widely used in the aircraft structural constructions for joining of the similar and dissimilar materials. The bond strength mainly depends on the type of adhesive and its properties. Dual adhesive bonded single lap joint concept is preferred where there is large difference in properties of the two dissimilar adherends and demanding environmental conditions. In this work, Araldite-2015 ductile and AV138 brittle adhesives have been used separately between the dissimilar adherends such as, CFRP and aluminium adherends. In the dual adhesive case, the ductile adhesive Araldite-2015 has been used at the ends of the overlap because of high shear and peel strength, whereas in the middle of the bonded region the brittle adhesive AV138 has been used at different dimensions. The bond strength and corresponding failure patterns have been evaluated. The Digital Image Correlation (DIC) method has been used to monitor the relative displacements between the dissimilar adherends. Finite element analysis (FEA) has been carried-out using ABAQUS software. The variation of peel and shear stresses along the single and dual adhesive bond length have been captured. Comparison of experimental and numerical studies have been carried-out and the results of numerical values are closely matching with the experimental values. From the studies it is found that, the use of dual adhesive helps in increasing the bond strength.

The stresses in single lap joints with a functionally graded adhesive bondline: an efficient modelling approach

AbstractIn this work, an efficient analytical model for the stress analysis of single lap joints with a functionally graded adhesive bondline is proposed which considers peel as well as shear stresses in the adhesive. The model takes into account the nonlinear geometric characteristics of a single lap joint under tensile loading and allows for the analysis of various adhesive Young's modulus variations. The obtained stress distributions are compared to results of detailed Finite Element analyses and show a good agreement for several single lap joint configurations. In addition, different adhesive Young's modulus distributions and their effect on the peel and shear stresses are studied and discussed in detail. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Nondimensional analysis of single lap joint subjected to out-of-plane loading

Transverse deflection of a single lap joint subjected to both in-plane and out-of-plane loadings is analyzed, incorporating nondimensional analysis. Solution from such analysis can then be exploited in obtaining the energy release rate and global mode mixity of a cracked single lap joint. Being contingent on debonding propensity of the crack tips, the kinetic energy absorption capacity in the event of low-velocity impact is examined based on global energy-balance consideration. Results reveal that calculations of change in impact energy level in experiment, as well as energy release rate and mode mixity in numerical models are comparable with nondimensional model. Though a gain in energy release rate is expected, the presence of in-plane loading also appears to improve the impact energy absorption capacity at high kinetic energy level. For a reasonably design estimate of low-velocity impact behavior of a single lap joint, the nondimensional analysis presented is considerably less cumbersome to handle.

The Use of the Boundary Element Method in the Analysis of Single Lap Joints

The most common techniques for stress analysis/strength prediction of adhesive joints involve analytical or numerical methods such as the Finite Element Method (FEM). However, the Boundary Element Method (BEM) is an alternative numerical technique that has been successfully applied for the solution of a wide variety of engineering problems. This work evaluates the applicability of the boundary elem ent code BEASY as a design tool to analyze adhesive joints. The linearity of peak shear and peel stresses with the applied displacement is studied and compared between BEASY and the analytical model of Frostig et al., considering a bonded single-lap joint under tensile loading. The BEM results are also compared with FEM in terms of stress distributions. To evaluate the mesh convergence of BEASY, the influence of the mesh refinement on peak shear and peel stress distributions is assessed. Joint stress predictions are carried out numerically in BEASY and ABAQUS®, and analytically by the models of Volkersen, Goland, and Reissner and Frostig et al. The failure loads for each model are compared with experimental results. The preparation, processing, and mesh creation times are compared for all models. BEASY results presented a good agreement with the conventional methods.

Three-Dimensional Finite Element Analysis of Single-Lap Joints: Effect of Adhesive Thickness and Poisson's Ratio

Three-dimensional (3D) elastic stress distributions in the vicinity of overlap corners of single-lap joints are investigated. A detailed 3D finite element (FE) model is carried out to study the intensity of the in-plane and out-of-plane stress distributions along the plate width direction. The effects of adhesive thickness and Poisson's ratio are also studied. The FE results show the presence of coupled modes at the overlap corners of the joint. In particular, sharp increment of out-of-plane fracture mode very near the lateral free surface of the joint is worth noting.

Modelling and Analysis of Hybrid Composite Joint Using Fem in Ansys

Composite materials are widely used in the various Fields. Due to the high strength they are widely used in the low weight constructions and also used as a suitable alternative to metals. In various applications and also for joining various composite parts together, they are fastened together using adhesives or Mechanical fasteners. Modeling and static analysis of 3-D Models of joints such as bonded, riveted and hybrid. The results were found in terms of vonmises stress, shear stress, and normal stress for stress distribution. ANSYS FEA tool has been used for stress distribution characteristics of various configurations of double riveted single lap joint with three joining methods namely bonded, riveted and hybrid the present study deals with the analysis of single lap joint subjected to the given tensile load and the stress distribution in the members under various design

Effect of protrusion at the ends of bondline in single lap joints under tension and bending

In this work, elasto-plastic stress analysis of single lap joints with and without protrusion in adhesive bondline subjected to tension and bending was carried out using 2D non-linear finite element analysis and confirmed experimentally. AA 2024-T3 aluminum adherends were bonded with SBT 9244 film adhesive. The protrusion was obtained by extending the adhesive film by 2 mm from the overlap length at both overlap ends. Three different adherend thicknesses and overlap lengths for each loading and bondline type were used. The joints with and without protrusion, for comparison, were loaded with the same load for each adherend thickness and overlap length. Finally, it was observed that the protrusion reduces the strength in the joint under tension, while the protrusion increases the strength in the joint under bending.

Green power—“molten” starch adhesives

A novel ‘green’ starch-based adhesive for bonding aluminium has been developed. Detailed thermal analysis studies show that ‘liquid starch’ obtained during controlled thermolysis of starch could potentially eliminate the need for chromic and sulfuric acid treatments and non-renewable adhesives. It was found that these materials only act as adhesives in a narrow temperature range around 250 °C. Materials were investigated using thermal analysis, diffuse reflectance infrared spectroscopy and mechanical analysis of single lap joints.

Fully-coupled nonlinear analysis of single lap adhesive joints

This paper presents novel closed-form and accurate solutions for the edge moment factor and adhesive stresses for single lap adhesive bonded joints. In the present analysis of single lap joints, both large deflections of adherends and adhesive shear and peel strains are taken into account in the formulation of two sets of nonlinear governing equations for both longitudinal and transverse deflections of adherends. Closed-form solutions for the edge moment factor and the adhesive stresses are obtained by solving the two sets of fully-coupled nonlinear governing equations. Simplified and accurate formula for the edge moment factor is also derived via an approximation process. A comprehensive numerical validation was conducted by comparing the present solutions and those developed by Goland and Reissner, Hart-Smith and Oplinger with the results of nonlinear finite element analyses. Numerical results demonstrate that the present solutions for the edge moment factor (including the simplified formula) and the adhesive stresses appear to be the best as they agree extremely well with the finite element analysis results for all ranges of material and geometrical parameters.

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

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%.

Viscoelastic and viscoplastic stress analysis of adhesive joints

Abstract The viscoelastic and viscoplatic effects in an adhesively bonded joint are very important to understand. Most of the adhesives used in structural applications exhibit some viscoelastic-viscoplastic behaviour, especially at high temperatures and high stress levels. The redistribution of stresses and strains that occur in joints during the viscoelastic-viscoplastic deformation influences the strength of the joints considerably. At low load levels a linear viscoelastic material model may be applicable, and at higher load levels both linear viscoelastic and non-linear viscoplastic material models are active at the same time. This paper presents results from the stress analysis of single lap joints, both with and without a crack, and with viscoelastic and viscoplastic adhesives. The influence of the stress redistribution on the failure load of the joint is discussed, as well as a ‘rule of thumb’ which can account for the viscous effects in the engineering design. The influence of flaws in the joints is also discussed.

Viscoelastic and viscoplastic stress analysis of adhesive joints

The viscoelastic and viscoplatic effects in an adhesively bonded joint are very important to understand. Most of the adhesives used in structural applications exhibit some viscoelastic-viscoplastic behaviour, especially at high temperatures and high stress levels. The redistribution of stresses and strains that occur in joints during the viscoelastic-viscoplastic deformation influences the strength of the joints considerably. At low load levels a linear viscoelastic material model may be applicable, and at higher load levels both linear viscoelastic and non-linear viscoplastic material models are active at the same time. This paper presents results from the stress analysis of single lap joints, both with and without a crack, and with viscoelastic and viscoplastic adhesives. The influence of the stress redistribution on the failure load of the joint is discussed, as well as a ‘rule of thumb’ which can account for the viscous effects in the engineering design. The influence of flaws in the joints is also discussed.

Two-Dimensional Stress Analysis of Single Lap Joints

Two-Dimensional Stress Analysis of Single Lap Joints