Assessment of Residue Fatigue Life of Crankshaft Based on Theory of Fatigue Damage

Crankshaft is the most important moving part of diesel engine, and bears secular cyclic dynamic loads. In this paper, fatigue life prediction modeling and residue life assessment based on statistics of historical working state (SHWS) is conducted at crankshaft using fatigue damage accumulation (FDA) theory. First, its dynamic response of typical operation performance is analyzed with software ANSYS of finite element, and high stress zone is found. Second, via rain-flow cycle counting for stress-time obtained, together with SHOP, fatigue load spectra of key parts are compiled. Finally, FDA model is built up with nominal stress method, and residue life based on SHWS is predicted for crankshaft of diesel engine.