Grotian relation

The Grotian relation describes how the energy stored in a material's deformation (strain energy) relates to the work done by external forces and the resulting changes in the material's structure. Essentially, it quantifies the connection between the energy applied to deform a material and the internal energy stored during that process. This relationship helps engineers understand how materials respond under load, predict failure, and design safer structures. It emphasizes that the total energy input is shared between elastic deformation (reversible shape changes) and permanent damage, providing a comprehensive view of material behavior under stress.