Finite Element Stress Response Analysis of Stepped-Lap Adhesive Joints of Dissimilar Adherends Under Impact Tensile Loadings

Abstract

The stress variation and stress distributions in stepped-lap adhesive joints of dissimilar adherends under impact tensile loadings were analyzed in elastic range using three-dimensional finite element method. The impact loading was applied to the lower adherend by dropping a weight. The name of FEM code employed was DYNA3D. The effects of Young’s modulus of the adhesive, the adhesive thickness, a number of steps in the adherends, and combination of adherend’s materials on the stress variation and the stress distributions at the interfaces between the adherend and the adhesive were examined. As the results, it was found that the maximum value of the maximum principal stress σ1 occured at the outside edges of the interfaces of the lower adherend which was subjected to the impact loadings. The maximum value of σ1 increased as Young’s modulus of the adhesive and the adhesive thickness at the butted parts decreased and as the numbers of steps in the adherends increased. The maximum value of σ1 in adherend’s combination where the upper adherend was aluminum alloy and the lower adherend was steel, was larger than that of σ1 in opposite adherend’s combination. In addition, experiments to measure the strain response of joints subjected to impact tensile loadings using strain gauges were carried out. The measured strain response was compared with the numerical results. A fairly good agreement was found between the numerical and the measured results concerning the strain responses.Copyright © 2003 by ASME