EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Dealing with mechanical damages is a key element in achieving longevity and durability in materials. The reaction to cope with mechanical damages such as a crack or cut is a fundamental function of biological systems in nature called a self-repair mechanism. The self-repair mechanism can be subdivided into two main phases: self-sealing and self-healing. The knowledge of the self-sealing mechanism as an initial phase of the repairing process can be transferred from living nature to engineering materials systems. Bio-inspired self-sealing materials system can be implemented with mechanical metamaterials which their extraordinary mechanical properties are defined by their complex inner structure. Programmability in mechanical metamaterials can be obtained from a combination of logical elements to result particular functionalities. This can be established by taking advantage of flexible materials such as polymers, which are able to keep large elastic deformations without any irreversible plastic behaviour. In this talk, we present a novel design of a mechanical metamaterial with programmable functionality for crack detection as the prerequisite step of the self-sealing procedure. Detecting the crack tip will be the main characteristic of the metamaterial’s unit cell, where a significant conformation change will be generated by the crack tip. The change of the unit cell at the crack tip will be used for triggering the adjacent unit cells in the metamaterial to alter the stress state around the crack tip. Simulation of the designed structure under actual conditions is the most significant step which should be done to evaluate the functionality of the mechanical metamaterial. Hence, the realistic finite element modelling will be developed to simulate the nonlinearity and large deformation behaviour of a single unit cell and describe the self-sealing process in the whole metamaterial composed of a large number of unit cells.