2001 Volume 19 Issue 4 Pages 693-701
The stress wave propagation and the stress distribution in adhesive scarf joints with dissimilar adherends subjected to impact bending moments are analyzed in an elastic deformation using three-dimensional finite-element method (FEM). An impact load is applied to the joint by dropping weight. The one side of the adherend is fixed and the other side of the adherend is subjected to an impact load. FEM code employed is DYNA3D. The effects of scarf angles of the adherends, the adhesive thickness and Young's modulus of the adhesive, the combinations of materials of the adherends on the stress propagation and distributions at the interfaces are examined. The scarf angles are changed from 15 to 90 degrees. It is found that the maximum value of the Mises' equivalent stress σM appears at the interface between the adhesive layer and the adherend made of mild steel, and it is independent of the combinations of the adherend materials. In the case where the scarf angle is 45 degree, the maximum value of the Mises' equivalent stress σM is minimal. The stress σX is the greatest in all of stress components. The maximum value of the Mises' equivalent stress σM increases as the adhesive layer thickness and Young's modulus of the adhesive increase. It is seen that the position where the maximum value of the Mises' equivalent stress σM occurs moves toward edge of the adhesive interface as the thickness and Young's modulus of the adhesive increase. In addition, experiments were carried out to measure the strain response of the adhesive scarf joints subjected to impact bending moments using strain gauges. A fairly good agreement is seen between the analytical and the experimental results.
