MLife-Fatigue-Number of cycles to failure

Wind & Water Computer-Aided Engineering Software Tools
5

Dear Maryana,

Here are my answers to your questions:

  1. In the MLife CertTest examples, loads from FAST are processed directly for fatigue rather than first using the loads to calculate stress; calculating stress is likely the preferred approach, but requires tools (e.g., FEA) to be used as a post-process to FAST before using MLife. (MLife can process loads directly from FAST or post-process stress time series.) When processing loads directly, the S-N curve is treated in terms of load, i.e., “S” is a load with the appropriate load units (e.g., N for force and Nm for moment). My Mar 25, 2020 post in the following forum topic provides some guidance on how to calculate the associated load-based ultimate load (LUlt) used to define the S-N curve for thin-walled circular cross sections: Mlife - User Defined Distribution - #15 by Jason.Jonkman.

  2. Yes.

Best regards,