14. Durability
Figure 14.1 Durability example
RecurDyn/Durability is a fatigue analysis tool based on the initiation and propagation of a crack of structure. The durability analysis or the fatigue analysis is to predict the fatigue life, fatigue damage and safety factor from Stress or Strain Time History.
After obtaining the results such as stress and strain from a MFBD system contains FFlex body or RFlex body, RecurDyn/Durability can evaluate the fatigue results such as fatigue life, fatigue damage and safety factor. And then, the user can see these results of fatigue analysis through contour plots.
Generally, material fatigue usually occurs over a period of time in localized areas. And the material undergoes 3 phases before a complete fracture such as the material softening/hardening, the crack initiation, and the crack growth. The process from “crack growth” to complete fracture may be sudden and catastrophic. Therefore, it is necessary for engineers to predict when the crack initiates. RecurDyn/Durability provides a variety of life criteria for “crack-initiation” fatigue evaluations. And then RecurDyn/Durability provides more than a dozen of life criteria for fatigue criteria, which cover most of the common methods used in the industry for fatigue predictions. In addition, it comes with a fatigue material library contained 180 common materials based on SAE J1099.
Because the stress or strain results are needed in order to calculate fatigue results, the analysis of MFBD system contained any FFlex body or RFlex body should be performed first. Concerning the FFlex body, it is possible to calculate the fatigue results about all elements except for the Beam element. In addition, in order to perform the fatigue analysis about RFlex body, the RFI file for RFlex body should be contained the element information.