non-linear elasticity

Non-linear elasticity describes how certain materials deform under stress in a way that isn't directly proportional to the force applied. Unlike simple elastic materials (like rubber bands) that stretch and return to their original shape predictably, non-linear elastic materials may stretch more or less depending on the amount of force, and their behavior becomes more complex at higher stresses. This means their deformation isn’t a straight-line relationship but follows a curve. Such behavior is important in materials like biological tissues, rubber compounds, and advanced engineering materials, where understanding their elastic response helps in designing safer and more effective products and structures.