A theory of damage and self-regenerating materials

A new type of material is postulated that is self-regenerating in the context of damage processes. The theory is built mathematically within the framework of continuum damage mechanics. The mathematical formulation is both systematic and consistent. For the generation of such a pure material, use is made of a new form of the damage variable that is suitable for this purpose. The main characteristic of the postulated self-regenerating material is that it undergoes a process of re-integration and re-assembly upon further loading. The damage process is reversed, and full recovery of damage is achieved once a certain level of loading is reached. This process is also characterized by strengthening of the elastic modulus until the original virgin material is recovered. The formulation is described precisely both mathematically and graphically. It is understood that this material is hypothetical at the present time, but it is hoped that future progress in manufacturing will make the realization of this new material a reality. It is anticipated that the presented theory lays the groundwork for the analysis and design of a new class of materials termed self-regeneration material. Some earlier materials that may fit this description were introduced in the last 20 years as self-healing materials that have the structurally incorporated ability to repair damage caused by mechanical damage. A final section is added to show how the theory of self-regenerating materials as presented here can be applied to the healing of injured soft tissue. It is shown that one single equation can represent both the inflammation phase along with the regeneration/remodeling phase of injured soft tissue. Furthermore, this governing equation is characterized by two parameters that can be varied to fit experimental data, namely the integer exponent and the control parameter.