An experimental study on the dependence of the strength of adhesively bonded joints with thickness and mechanical properties of the adhesives

Abstract

Adhesive bonding joints are widely applied in many engineering fields. Their overall strength is much dependent on the thickness of adhesive layers. Many previous experimental studies have found that the ultimate failure strength of the bonding structure increases with the decrease of the adhesive thickness. However, few of them consider the effect of adhesive intrinsic material parameters on the relation between the overall strength and adhesive thickness. In the present investigation, the effect of the adhesive thickness on the overall strength of the lightweight metallic adhesive bonding joints was experimentally studied, considering the effect of the adhesive toughness. The results show that the variations of overall strength resulting from the adhesive thicknesses have remarkable discrepancy due to the toughness of the adhesive, which is in agreement with the previous model prediction.

Keywords:

• adhesive thickness
• toughness
• bulk shear strength of adhesive
• overall strength

Acknowledgments

This work was supported by the National Basic Research Program of China (No. 2012CB937500), the National Natural Science Foundation of China (No. 11021262, 10932011, 11023001, 11372318 and 91216108), and by the China Postdoctoral Science Foundation funded project (No. 2013M540033).