What is the time-dependent properties in ASME Code?

[Moong]

Hi everyone

I have been study about ASME secII-Part D.

I saw the "time-dependent properties" in the code. But there was no designation about it.

Anyone knows about that? Plz help me. Thank you

 

[TGS4]

If you look at Table 1A (for example), you will see that some of the allowable stress values are written in italics. It is these values that are governed by the time-dependent properties. If you carry on back to Appendix A, you will see the definitions of how the time-dependent allowable stresses are calculated. It's basically where creep governs over the short-term or time-independent mechanical behaviour.