How to calculate Strain limit in elastic plastic analysis-local strain limit (ASME VIII Div 2)

[sencae]

Hi Everyone
Can anyone guide me how to calculate how to calculate local strain limit Ɛpeq in equation 5.7 in Elastic plastic local strain limit in ASME VIII div 2.

Regards
Senthil ramajayam

 

[IdanPV]

Ɛpeq is something you need to obtain from the FEA software you use.
Most of the FEA softwares has the ability to display the total equivalent plastic strain, so it's pretty much depends on which software you are using.

 

[sencae]

Hi Idan thanks for your comments. Equation 5.7(Ɛpeq+Ɛcf<ƐL)
Where
Ɛpeq =Total equivalent plastic strain (obtain from FEA software)
Ɛcf = Forming strain(assumed Zero)
ƐL = Equivalent plastic strain (obtain from FEA software)
Example:
Ɛpeq = 0.037092,Ɛcf =0 & ƐL =0.038658
0.037092+0<0.038658
Please conform me whether model is safe or not.

Thanks
Senthil ramajayam

 

[TGS4]

The strain limit is calculated on an element-by-element basis.

In general, I prefer to create a variable in the FEA software that is (Ɛpeq+Ɛcf)/ƐL. When it is plotted, the value must be less than zero. Pay attention to discretization - see

https://asmedigitalcollection.asme.org/PVP/proceedings-abstract/PVP2013/55676/V003T03A096/284128

 

[DriveMeNuts]

Design by forum for free?

 

[sencae]

Hi can you please clarify my query, I can’t able to view your attachment due to login process.

 

[tigny]

When it is plotted, the value must be less than zero.

Do you mean less than one?

 

[TGS4]

tigny - my apologies - you are correct that the Strain Limit Damage Ratio (SLDR) shall be less than one.

 

[TGS4]

senthilramajayam80 - you need to buy the paper from ASME. You will not be provided anything here for free. What have you done to learn the topic yourself? Have you taken a training course on this topic?

 

[sencae]

thanks for your reply. I learn this topic by myself, if you have any training courses please let me know.