Fatigue of Endless Fiber-Reinforced Composites - a novel failure mode-based approach-

Fiber-dominated designed laminates are often used.Experience shows: laminates composed of UD laminas, statically designed to a design strain limit ε < 0.3% do not fatigue. However, lightweight design requires a higher excertionof the material. The author presents a rigorous engineering-like method that is based on his successful ’Failure Mode Concept’for fatigue life estimation.

It consists of :

(1) failure mode-based modeling of the varying operating stress,

(2) measurement of Master-S/N-curves for the activated failure mode (fiber fracture),

(3) determination of necessary other S/Ncurves employing the principle of ‘equality of strain energy’,

(4) application of the damaging accumulation hypothesis of Miner.