Study of the Life Span of Adhesively Bonded Single Lap Joint Due to Creep

Resumo

Adhesive joints are often used in several areas, including offshore systems and automobiles. The development of suitable models to predict the joint behavior has several challenges, especially due to creep phenomena. The aim of this study is to investigate the creep lifetime of single lap joints considering two different adhesives (epoxy and polyurethane). Long-term tests are performed using a pneumatic creep equipment (PCE). The parameters to the creep model are obtained for each adhesive, where load and life span are related. The models obtained and the times of joints life span are compared with two other adhesives previously studied. The results confirm that the knowledge of the lap shear strength value is just a reference to the designer, however experimental tests in creep for each different adhesive is necessary. The comparison between the joints bonded with two different epoxies shows similar results, what was demonstrated by the similar curves obtained by the models. The comparison between polyurethane adhesives did not show similar behavior in the curves obtained from the models, especially in the time of life span.

Keywords: Creep, single lap joints, life span, bonded joint.