Rissfortschritt

Rissfortschritt is a term used in materials science and engineering to describe the progression of cracks within a material under applied stresses. It covers crack initiation, stable crack propagation, and rapid fracture, and is a central concern in fracture mechanics and structural integrity assessment.

Crack growth is influenced by loading mode (Mode I, II, III) and by environment and material properties. In fatigue and fracture mechanics, growth rate is often described by relationships such as Paris law, da/dN = C(ΔK)^m, with da/dN the advance per cycle and ΔK the stress intensity factor range. Temperature, corrosion, microstructure, and residual stresses affect propagation. Transition from stable to unstable growth determines remaining life.

Experimental approaches include fatigue tests, fracture toughness tests, and methods to measure crack length. Non-destructive evaluation methods such as ultrasonic testing, eddy current, and acoustic emission monitor progression. Models range from deterministic fracture mechanics to probabilistic life predictions, often using finite element analysis to compute K, J-integrals, or cohesive zone models.

Understanding Rissfortschritt informs design choices, inspection intervals, and maintenance planning in airplanes, bridges, pressure vessels, and energy infrastructure. It supports safety standards, reliability assessments, and lifetime prediction.

The term is common in German-language literature; in English texts, crack growth or crack propagation is used. Related concepts include fracture toughness, crack initiation, and crack arrest.