Fatigue
In the Material Definition dialog box, from the Material Type list select Isotropic. Note that you can use only isotropic materials for a fatigue analysis. From the Fatigue list, select Unified Material Law (UML). The following options for material properties appear in the Fatigue area on the Material Definition dialog box:
• Material Type—Select a material type to use.
The fatigue properties in the Fatigue Advisor are used to model low alloy steels, unalloyed steels, aluminium alloys, and titanium alloys. The fatigue properties are derived from the Uniform Material Law (UML) as proposed by Baumel & Seeger in Materials: Science Monographs, 61, “Materials Data for Cyclic Loading, Supplement 1”; ISBN: 0 444 88603 6.
As per the UML, steels are classified into unalloyed, low alloyed and high alloyed. The UML was derived from the unalloyed and low alloyed data. Stainless steels are classified as high alloyed but the UML is not very accurate for stainless steel.
Unalloyed steels consist of steels such as the SAE 10xx series, and HSLA. Low alloy consist of steels such as 4130, 8620.
The aluminium estimator is based on aluminiums in the 1000, 2000, 5000, 6000 & 7000 series. Cast aluminiums are not included in the fit.
• Surface Finish—Select a surface finish option for your model. The surface finish option is only appropriate for ferrous alloys. It should not be used for aluminium.
• Failure Strength Reduction Factor—Type a failure strength reduction factor (Kf) greater than or equal to 1. This factor is used to reduce the endurance limit to account for unmodeled stress concentrations, such as those found in welds, or other material or environmental factors.
 |
You must specify the Tensile Ultimate Stress in the Material Limits area of the Material Definition dialog box. A red asterisk next to Tensile Ultimate Stress indicates that it is a necessary parameter.
|
Return to Isotropic or Fatigue Analysis.