Damage Accumulation Theory is a concept used to explain how materials, such as metals and polymers, degrade over time under stress. It suggests that materials accumulate damage from repeated loading or environmental factors, leading to eventual failure. This theory helps predict the lifespan of materials in various applications, including construction and manufacturing. The theory is particularly relevant in fields like materials science and engineering, where understanding material behavior is crucial. By analyzing the rate of damage accumulation, engineers can design safer and more durable products, ensuring they meet performance standards throughout their intended lifespan.