Adhesively bonded joint brittle fracture assessment via average strain energy density criterion

The average strain energy density (ASED) criterion applied to design of notched mechanical components has been achieved a considerable success over the years thanks to its numerous advantages including the need for a relatively coarse mesh, the use of a scalar rather than vector quantity and the ability to compare the strength of parts with different notch angles. It is known that adhesively bonded joints mechanical strength is governed by the stress singularity arising near the intersection between the adhesive-substrate interface and the free surface of the bonded joint, even without notches. This is due to the different elastic material properties of the adhesive compared to those of the substrate that induces a constitutive stress singularity. This phenomenon makes the strain energy density criterion particularly suitable for the design of bonded joints, as well. This contribution is aimed at applying the ASED criterion to the static strength assessment of bonded joints. Experimental results taken from literature were found in good agreement with those predicted by the ASED approach.