Finite element analysis has been carried out to obtain the interfacial stresses in a single lap joint using a special 6-node isoparametric element for adhesive layer. The analysis results are found to be in good agreement with the closed-form solution of Goland and Reissner. The peak normal and shear stresses found in the adhesive layer at the edges of the joint are due to stress singularity. The bond strength of the single-lap joint is estimated considering one of the stress fracture criteria known as the point stress criterion. Bond strength estimates are found to be reasonably in good agreement with existing test results.Introduction. Adhesive bonding can offer better performance over the mechanical fastening and being used extensively in space, automobiles, construction industries, packaging industries etc. It has the ability to join dissimilar materials and to join efficiently thin sheet materials such as thin-walled composite structures [1]. Single-lap joint [2-7] and double-lap joint [8,9] are simple in geometry and are widely used in characterizing adhesive behavior and structural connections. Failures in an adhesive joint are classified as adhesive and cohesive failure.Adhesive failure occurs at the interface between the adhesive and adherend, whereas, the cohesive failure occurs either in the adhesive or in the adherend. Failure analysis of an adhesive joint requires reliable structural deformation and stresses in the joint for the applied loads. The mechanisms of adhesion are related to chemical and physical properties of the adhesive polymers. The structural deformation and stress states for the bonded joint configuration can be obtained by specifying material properties of the joint configuration, loads and appropriate boundary conditions. Since there is no unique failure criterion for the bonded joints, the designer has to select or establish a suitable criterion to estimate the joint strength [10][11][12][13][14][15][16][17][18][19]. The stress distribution for simple geometries can be obtained from a closed-form solution, which will be useful to validate the finite element models. Finite element analysis (FEA) is essential for analyzing complex geometries and structural materials. Da Silva et al. [20] have reviewed several analytical models. Stress analysis has been carried out for various joint configurations having different adherend and adhesive properties [21][22][23][24][25][26][27][28].Standard finite elements are not well suited for modeling the adhesive layers which are extremely thin as compared to other dimensions of the bonded structure. Reasonably accurate results can be expected from the standard finite elements when the aspect ratio of the width to the height of the element is approximately unity. An element having a large aspect ratio becomes much stiffer in the transverse direction and much weaker in the axial direction. Backer and Hatt [29] have developed a linear element assuming thin adhesive layers which behave elastically as simple tension-compression springs and shear spring...

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Functionally graded materials (FGMs) are advanced composite materials characterized by their variation in the composition or microstructure in a specific direction. The composition of FGMs is continuously varying. The desired properties can be achieved in a single bulk material of FGM which makes them especially applicable for mechanical and tribological applications. Using a vertical centrifugal casting machine fabrication of aluminium A 356-SiCp functionally graded metal matrix composites (FGMMC) were done. 10% by volume of SiCp particle were taken. An average size of 34 μm is chosen for additive SiCp, so that dispersed particulate matter in matrix of A-356 will enhance mechanical and tribological properties such as wear resistance, ultimate strength and hardness. The castings were carried out at 1100 rpm, 1200 rpm, 1400 rpm, 1550 rpm, 1700 rpm and 1950 rpm of the machine. The microstructural analysis projects a good gradation at 1700 rpm. The observations are validated using hardness analysis. Dry sliding wear behaviour of FGMMCs fabricated at rotor speeds of 1550 rpm, 1700 rpm and 1950 rpm were done. Hardness improvement at outer radial position than that of inner radial position of FGMMCs are 1.19, 1.29, 1.35 and 1.54 times at speeds 1400, 1550, 1700 and 1950 rpm of the machine respectively. The casting at 1700 rpm showed a good gradation at transition region compared to others. Wear resistance at outer surfaces of FGMMCs are improved with the presence of SiCp at the expense of COF.

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