Fatigue life thick-bonded glued joints subjected to aging

The paper presents the results of experimental tests under static and cyclic loads of thick-layer adhesive joints. The test specimens were made of X2CrNi12 steel sheet (PN-EN 10027-1: 2007), 1.6 mm thick. BETAMATE BTR adhesive was used for gluing. Bonding was carried out under strictly controlled conditions, i.e. 20 °C and 23 % humidity. The specimens underwent aging in various conditions. Subsequently, experimental tests were carried out under static load. The obtained results allowed to determine: tension strength of glued joints S_u, yield stress S_{y 0.2}, elastic modulus E and elongation ΔL. Plots of static strength allowed to calculate the value of work W, needed to damage the joint. The second stage of the research covered of determination of the aging effect of the specimens on fatigue life. The research was carried out in the conditions of constant amplitude loads with asymmetric cycle coefficient R = 0. The obtained results allowed to assess the influence of the aging process of adhesive joints on its fatigue life.