stress intensity factor equation

The stress intensity factor (K) measures how much stress is concentrated around a crack tip in a material, indicating the potential for crack growth. It depends on the applied load, the crack size, and the geometry of the part. Essentially, K helps predict whether a crack will stay stable or grow, which can lead to failure. When K reaches a critical value (fracture toughness), the crack can propagate rapidly, causing the material to break. This concept is vital in assessing the durability and safety of structures like bridges, aircraft, and pressure vessels.