This lecture covers the application of orthotropic continuum damage models in structural analysis, focusing on the behavior of materials under tension-compression states and the recovery of stiffness upon load-reversal. The instructor discusses different damage evolution laws, stress-strain curves, and the representation of cracks opening and closing under reverse loading. Examples of damage origin in a church are presented, along with the use of orthotropic models to simulate concrete and masonry behavior. The lecture also touches on the combination of damage-plasticity models and the importance of including irreversible deformations in the analysis.