Experimental and numerical study on tensile failure behavior of bionic suture joints

Sutured architectures with weak interfaces, such as bone or nacres, have a great potential in engineering for the design of joints. In this investigation, which is inspired by the subtle designs that occur in nature, the geometrically structured interfaces of living and fossil organisms are converted into a model for a suture joint. Through a combined numerical and experimental study using three-dimensional (3D) printed suture joint specimens, the tensile failure behavior of first-order bionic suture joints is systematically studied. The deformation and failure mechanisms of the joints are explored through detailed parametric studies of critical geometric parameters. The results indicate that a suture interface having a sinusoidal centerline introduces an interlocking effect during tensile loading, and the interlocking can enhance the overall toughness and load-carrying capacity of the joint. Incorporating features such as a small tooth tip angle, a high amplitude of the sinusoidal centerline, and high interface strength into the design of the suture geometry/interface can improve the bearing performance of the joint. This study presents a robust modeling method and provides fundamental insights into the engineering design of bionic suture joint structures.