The article is devoted to the estimation of fatigue life of dynamically loaded components in the frequency domain using numerical methods of mechanics. The theoretical part presents basic knowledge about statistical processing of random signals, probability models and fatigue damage models. The practical part describes the process of determining S-N curves for smooth and notched test specimen and experimental and numerical analysis of fatigue life of the beam excited by random signal.The article is devoted to the estimation of fatigue life of dynamically loaded components in the frequency domain using numerical methods of mechanics. The theoretical part presents basic knowledge about statistical processing of random signals, probability models and fatigue damage models. The practical part describes the process of determining S-N curves for smooth and notched test specimen and experimental and numerical analysis of fatigue life of the beam excited by random signal.