Review of fatigue of bulk structural adhesives and thick adhesive joints

Fatigue of structural adhesives has been investigated through joints and a little number of works investigate bulk adhesive behaviour itself. Aerospace and automotive engineering focuses more on joint configuration studies, which are correlated with practical applications. Previous works showed that for thin adhesive joints, material properties measured by bulk adhesive testing and joint testing are similar despite the triaxial stress states developing in the adhesive bondlines. However, with the introduction of structural adhesives in construction industry, thicker bondlines have emerged where the bulk adhesive material dominates the joint behaviour. This review work summarises works on the fatigue of bulk structural adhesives used mainly in the construction industry investigating structural adhesives fatigue behaviour either through experiment on joints or on bulk adhesive specimens. The work focuses on thick adhesive bondlines in joints, and discusses the controversy that is over whether adhesive properties from joints or from bulk material should be used.