An experimental study on the failure behavior of composite suture joint structures

The mechanics of nature suture joints have be concerned by researchers because of their designability of mechanical properties. Our previous numerical work [1] reveals the great potential of composite suture joint structure as an alternative engineering joint structure. The failure mechanism of suture joint structures are complicated due to the complex interfacial geometry, and the interactions between the damage and failure mechanism and interface geometry feature need further investigation. In this paper, a series of suture joint samples have been fabricated by using 3D printing technology. The tensile failure behavior and the strain distribution of suture samples were measured using Digital Image Correlation (DIC) method to study the phenomenon of interfacial crack initiation and propagation. The experimental results indicate that the tip angle plays as a main control parameter, which affects significantly the interface damage behavior and the overall structure load capacity. This work further improves our understanding on the relationship between mechanical strength, damage mechanism and suture geometry. It also provides validation data for the improvement of numercial models, which will be used for the design and optimization of novel high performance composite joint structures.