フィレットを持つ重ね合せ接着継手の応力分布と疲労強度

抄録

In adhesive bonded lap joints, stress in the adhesive layer is concentrated at the lap end because of difference in elastic moduli of constituents and abrupt thickness change. Hence, in order to improve the joint stength by reducing the stress concentration in the adhesive layer, it is practiced in industry to form it with a fillet of adhesive spew or to round the corners of the adherend. However, there are few studies on the fatigue strength charactristics of these improved adhesive joints.
In order to investigate the relation between the fatigue stength of these joints and the local stress distribution near the lap end, a series of fatigue tests were conducted on the adhesive bonded lap joints with an adhesive fillet plus a rounded adherend, and the local stress near the adherend corner was analysed by FEM. Furthermore, the fatigue crack propagation behavior was observed with an optical microscope.
As a result, It is confirmed that the fatigue strength of lap joints with different corner radii can be standardized by the maximum value of maximum shear stress near the lap end.