How to calculate deformation strain in an ellipse?

[sma2000]

Hello all,

Can you show me a simple method to estimate the deformation strain in an ellipse? For example, I use a straight 0.5 mm wire, and formed it to an ellipse shape, with hemi-axis a=20mm and b=10 mm. What about the maximum deformation strain of the wire? Thanks a lot in advance.

 

[CoryPad]

Strain [ε] can be calculated using wire thickness t and formed radius r:

[ε] = t/2r

For your example, the strain [ε] = 0.5/(2[·]5) = 0.05

 

[sma2000]

Thanks a lot. Can you explain a little bit detail the procedure to get the radius?

 

[CoryPad]

I estimated the small radius to be half the minor axis, and I assumed your b = 10 referred to the minor axis. Now that I look at your original post more closely, I suppose I should have used 10 instead of 5 since you used the word hemi-axis. In English, the term is semiminor axis.

 

[Maui]

I think that a picture would gives us all a better idea of what exactly you are doing here. From your original post it is unclear what type of deformation the wire is actually undergoing.

Maui

http://www.EngineeringMetallurgy.com

 

[sma2000]

Thanks. The picture should be the easiest way to get that.