Stressnyúlás

Stressnyúlás is a Hungarian term that translates to "stress-induced stretching" or "stress elongation." It describes a phenomenon observed in certain materials, particularly plastics and some metals, where prolonged exposure to stress, even below the material's yield strength, can lead to a gradual and permanent increase in length. This effect is distinct from elastic deformation, which is temporary and reversible.

The process of stressnyúlás involves the slow rearrangement of the material's internal structure under constant tensile or compressive load. In polymers, this can involve the uncoiling and alignment of polymer chains. In metals, it can involve the movement of dislocations. This gradual deformation occurs over time and can be influenced by factors such as temperature, the magnitude of the applied stress, and the specific properties of the material.

While elastic deformation returns to its original shape once the stress is removed, stressnyúlás results in a permanent change in the material's dimensions. This can be a critical consideration in engineering applications where dimensional stability is important. For instance, components subjected to long-term static loads might experience stressnyúlás, potentially leading to decreased performance or failure over time. Understanding and accounting for stressnyúlás is therefore essential for reliable material selection and design.