Calculating minimum reserve factor in an I-beam

[Jadamog]

Hi Everyone, I am confused about how to calculate the minimum reserve factor against yielding and fatigue in an I-beam clamped at both ends. I have calculated the maximum bending stress from it's deflection due to a load in the middle of the beam, and I know the cross-sectional area of the I-beam. Is it now possible to calculate the reserve factors?

 

[SteamKing]

If by 'reserve factor' you mean 'safety factor', you would need to know the strength characteristics of the material used to fabricate the beam, i.e. its yield strength. Yield strength is not the same as modulus of elasticity.

 

[Jadamog]

If by 'reserve factor' you mean 'safety factor', you would need to know the strength characteristics of the material used to fabricate the beam, i.e. its yield strength. Yield strength is not the same as modulus of elasticity.

Thanks for the reply, yes I do mean the safety factor. And I do have all the strength characteristics of the beam, sorry I forgot to mention that in the original post. So is it now possible to calculate the safety factors?

 

[SteamKing]

Sure. Go ahead.

 

[Jadamog]

Sure. Go ahead.

Ha, I would if I know exactly what I was doing but I'm still confused on how to get started, do I have to create a Goodman diagram to see how many cycles to failure first?