Figure 1 Fatigue Evaluation dialog box
You can select one of the following life criteria for fatigue evaluations.
Stress-based life criteria
•Morrow
•ASME boilers and pressure vessels
•BWI (BS7608)
•Weld life criteria for fatigue damage assessment and life prediction
•User-Defined
Strain-based life criteria
•Manson-Coffin
•Morrow
•Smith-Watson-Topper
•Maximum Shear Strain
•Brown-Miller
•User-Defined
Safety factor
•Goodman safety factor
•Gerber safety factor
•Modified Goodman safety factor
For the selection reference of Life criteria, the user can refer to the Table 1. Also, if the user wants to get more information about Life criteria, the user can refer to the Theory of RecurDyn/Durability.
Mean Stress Effect
Mean stress effect is only available on Stress-based life criteria. To get detail information related to this effect, please refer to ‘Stress Life Criteria’ in the Theory of RecurDyn/Durability.
Searching Increment
In the maximum damage approach which is one of the Fatigue evaluation methods, RecurDyn/Durability calculates the uni-axial and bi-axial damage using the stress or strain history in different directions on element faces. The directions on element face are defined by using the user-defined incremental angle as shown in the Figure 2. At this point, Element Face coordinate system is the coordinate system defined on each element face which has the normal direction (Z-axis) perpendicular to each element face. So, if the incremental angle is smaller, the damage results will increase because of more directions to calculate and it will take longer to calculate the fatigue results.
Please refer to of Maximum Damage Approach of ‘Fatigue Evaluation Methods on Element face’ in the Theory of RecurDyn/Durability to get more information.
Figure 2 Definition of Incremental Angle