Strength Evaluation of Round Bar Butt Joint withRound Edged Adhesive Surface

Abstract

Stress analysis by finite element method was performed to study a rounding the edge of the adheringsurface of the round bar adherend and using an analytical model of butt adhering shape to estimate the tensilestrength of the butt joint. The tensile strength of the round bar butt joint, which adhesive surface had a roundedge, was calculated. Furthermore, the butt joint was actually made with the same shape as the analysis, andthe tensile test was carried out to show the validity of the analysis. The tensile test of the same shape butt jointwas conducted experimentally to confirm the result of the finite element method. As a result, it showed thatit is possible to reduce the influence of stress specificity by providing roundness on the edge of the bondingsurface. The influence of the stress singularity can also be decreased by adding the round edged surface. Themaximum value of the maximum principal stress in the adhesive layer was made equal to the strength of theadhesive using a joint model with rounded radius of 0.2 mm or more. It is found that the analysis value andthe breaking load value by experiment agreed well. The calculated value coincided with the experimentalvalue when the edge at the adhesive surface was more than 0.2mm and the maximum principal stress was thesame as the strength of the adhesive. In other words, by providing a radius of 0.2 mm or more on the edgeof the adhesion surface of the round bar adherend, round bar butt joints subjected to tensile loads using thestress-strain relationship and the finite element method of the adhesive to be used It is shown by analysis andexperiment that the strength evaluation is possible. This indicates that the strength of the adhesive round buttjoint, which has more than 0.2mm round adhesive surface edge, can be estimated using the relation betweenstress and strain of adhesive and the infinite method.