Material characterization of structural adhesives in the lap shear mode
A general method for characterizing structural adhesives in the bonded lap shear mode is proposed. Two approaches — semi-empirical and theoretical — are assessed. The semi-empirical approach includes Ludwik's and Zhurkov's equations to describe, respectively, the failure stresses in the constant strain-rate and constant stress loading modes with the inclusion of temperature effects. The theoretical approach is used to describe adhesive shear stress/strain behaviour by utilizing viscoelastic or non-linear elastic constitutive equations. On the basis of this approach an empirical extension of Crochet's delayed failure equation is proposed to account for the effects of high temperature.