Fatigue Life Prediction Method Based on Cyclic Plastic Zone Size for Arc-Welded Structures which Used Virtual Prototype Vehicles

The study by the “Committee on Fatigue Strength & Structural Reliability “of the Society of Automotive Engineering of Japan (JSAE) reveals that the method of fatigue life prediction based on cyclic plastic zone size (ω*) which proposed by Koibuchi at el.^{(1) (2) (4) (5)} have accurate prediction ability for the fatigue life of arc-welded joint. But in this method solid elements with sides smaller than 0.001mm long for calculation of ω* is required and it is not practical to apply for all the arc-welded parts in an entire vehicle. Then, The method of simply calculating ω* etc were examined, and fatigue life prediction method based on ω* for arc-weld structures which used virtual prototype vehicles was developed. Moreover, the validity of the method was verified from the comparison with the fatigue test result.