Nonlinear superhealing and contribution to the design of a new strengthening theory

Self-healing materials have recently become more popular due to their capability of self-repairing cracks and rehabilitation of structures. Recent research has revealed that self-healing presents a crucial solution for the strengthening of the materials. This new concept has been termed superhealing. Once the stiffness of the material is recovered, further healing can result in a strengthening of the material. This work presents a refined theory of the superhealing model within the framework of continuum damage mechanics. The proposed refined theory is extended in this paper from linear to nonlinear superhealing theory. The general framework of continuum damage-healing mechanics is first reviewed. Following that, the concepts of healing and superhealing of materials are introduced along with both their isotropic and anisotropic presentation. The proposed linear refined theory of superhealing materials and its anisotropic definition are presented using sound mathematical and mechanical principles. Afterwards, the nonlinear formulation of the refined superhealing theory and its anisotropic presentation are introduced. In addition, the link of the proposed theory with the theory of undamageable materials is outlined. Examples for the case of plane stress and one-dimensional element are demonstrated in which the refined theory of superhealing is applied. The aim of the present work is to present the proposed refined theory and provide guidance regarding the concept of the new theory that can be applied in manufacturing technology in the future. It is hoped that the new theory will open an area of new research in materials science and pave the way for new technologies that can be exploited for rehabilitation of structures.