Metal Fatigue
Metal fatigue is a type of failure that happens when a metal part is subjected to repeated loading and unloading over time. Even if each load is below the metal’s normal strength, small cracks can start at points of stress concentration such as sharp corners, holes, weld toes, scratches, or surface defects. With continued cycles, the crack can slowly grow until the part breaks, often with little warning.
Fatigue is common in parts that experience vibration or fluctuating forces, such as shafts, springs, fasteners, frames, and rotating equipment. Reducing fatigue risk usually involves lowering stress concentrations with smooth transitions and generous radii, improving surface finish, using proper weld design, avoiding overloading, and selecting materials and heat treatments suited for cyclic service. Regular inspection is also important when fatigue failure would be a safety concern.
Fatigue is common in parts that experience vibration or fluctuating forces, such as shafts, springs, fasteners, frames, and rotating equipment. Reducing fatigue risk usually involves lowering stress concentrations with smooth transitions and generous radii, improving surface finish, using proper weld design, avoiding overloading, and selecting materials and heat treatments suited for cyclic service. Regular inspection is also important when fatigue failure would be a safety concern.
