Computing max tensile and compressive stress in a bar

[tyler300ZX]

Homework Statement

I've used all the proper equations and done all the work with no problem. My only question is when computing the maximum stress, how do I know which one is the tensile and which on is the compressive? I've attached all my work and came out with Max stress = 3.84 Mpa and Max stress = 2.77 Mpa. I just want to know how I decide which one is compressive or tensile stress. Thanks!

Homework Equations

The Attempt at a Solution

strengths

 

[tyler300ZX]

Sorry first post and all the work is already done, so my formatting is probably incorrect

 

[SteamKing]

Homework Statement

I just want to know how I decide which one is compressive or tensile stress. Thanks!

Based on just how his beam is loaded, what would you expect the deflection of the beam to be? Would it curve up or down in the center?

 

[tyler300ZX]

The beam is going to bend in the shape of a U. So it'll bend down in the center

 

[tyler300ZX]

haha sorry its going to bend up in the center, like an lower case n.

 

[tyler300ZX]

Based on just how his beam is loaded, what would you expect the deflection of the beam to be? Would it curve up or down in the center?

Thanks man I think i figured it out. The top is going to be experiencing tension and the bottom compression. Thank you!

 

[Chestermiller]

Thanks man I think i figured it out. The top is going to be experiencing tension and the bottom compression. Thank you!

An easy way to remember this is that the outside of the bend is in tension and the inside of the bend is in compression.