väsymisvaurioprosessi

Fatigue failure process, or väsymisvaurioprosessi in Finnish, refers to the progressive and localized structural damage that occurs in a material under repeated or fluctuating loads. This type of failure can happen even if the applied stress is well below the material's ultimate tensile strength. The process typically begins with the formation of microscopic cracks at stress concentration points, such as surface imperfections, sharp corners, or inclusions within the material. These cracks then propagate incrementally with each load cycle. As the cracks grow, the effective cross-sectional area of the component decreases, leading to an increase in stress at the crack tip. Eventually, the crack reaches a critical size, and the remaining material can no longer withstand the applied load, resulting in sudden and catastrophic fracture. The rate of crack propagation is influenced by factors like the magnitude of the applied stress, the stress ratio (the ratio of minimum to maximum stress), the material's properties, and the presence of environmental factors like corrosion. Understanding the fatigue failure process is crucial in engineering design to ensure the longevity and safety of components subjected to cyclic loading.