Section VIII, Div 2, Appendix 5C, non linear portion of temperature distribution

[hhamza]

I'm having a couple of issues with this part of the code.

Equation 5-C.5, Tp is asking you to add a function (T) with a scalar. Additionally, they're asking you to add a temperature (Tavg) with a Temp per inch value (2Tb/t). Am i missing something?

Any clarification with this portion of the appendix would be appreciated.

Thanks,

 

[TGS4]

First, have you gone through PTB-1? Second, rather than going through this complicated procedure, why don't you do an elastic-plastic fatigue analysis?

 

[hhamza]

I don't have access to PTB-1 unfortunately.

I haven't really looked at 5.5.4. Any reason you would recommend using that method instead?

Thanks,

 

[TGS4]

Unfortunate about PTB-1. You should rectify that problem - you are doing work to Division 2, after all.

Look at the logical sequence in which you found yourself in Annex 5-C. You were going through 5.5.3, and realized that you wanted to separate out the local thermal stress ranges. First off, that tells me that using the entire stress range, as in Equation 5.36, resulted in a "fail". So, you needed to separate out the thermal from the non-thermal - for the purposes of applying the Poisson correction to only the thermal stress range, and the Kf and (more importantly) the Ke to the non-thermal stress range.

All of that complication can be avoided if you perform an elastic-plastic fatigue analysis.

Does that make sense?