Tensile strength explanation

[hwp]

<font color="blue">" Not to be confused with the load on a beam, in tension... " </font>

A simple beam is subject to two types of stress, shear and bending moment. The shear force comes from the load itself attempting to cut the beam. The bending moment comes from the beam attempting to resist deflection causing tension on the lower part of the beam and compression on the upper part of the beam.

 

[turbo36]

</font><font color="blue" class="small">( causing tension on the lower part of the beam and compression on the upper part of the beam. )</font>

Don't you mean just the opposite?

 

[D80]

HWP IS CORRECT THE BEAM WILL BE IN COMPRESSION ON THE TOP AND TENSION ON THE BOTTOM.

D80

 

[slowzuki]

yip. If you want to get into young's modulus and elastisity too we can!

 

[turbo36]

Actually,depending on how the beam is supported and how the force is applied we can both be right . /forums/images/graemlins/wink.gif I was assuming the beam was fixed on one end and the load was applied on the opposite end (like a flag pole). It wasn't until I read your reply that I realized HWP was probably describing a beam that was supported on both ends and the load evenly distributed (like a bridge).

 

[slaveToHorses]

yup, because hwp was expounding on my point about not confusing the issue with "a load on a beam, in tension".
It's that "in tehnsion" part /forums/images/graemlins/smile.gif
Obviously he couldn't control himself either!

 

[BlueRidge]

</font><font color="blue" class="small">( Actually,depending on how the beam is supported and how the force is applied we can both be right . /forums/images/graemlins/wink.gif I was assuming the beam was fixed on one end and the load was applied on the opposite end (like a flag pole). )</font>

/forums/images/graemlins/grin.gif I had the same problem. I was trying to figure out how someone could be so mixed up! /forums/images/graemlins/tongue.gif

 

[hwp]

I see that I needed to provide more explanation in my earlier post. I specifically reffered to a "simple" beam which is defined as being supported at both ends and is assumed not to transfer bending moments at the ends. A cantilevered beam is an entirely different situation and must transfer a bending moment at the "fixed" end. A cantilevered beam will have tension on the loaded side while a simple beam will have compression on the loaded side. /forums/images/graemlins/smile.gif

 

[turbo36]

It's interesting how two people can interpret something completely different. In my early engineering career all the beam calc's we did were cantilever, so when I hear the term "simple beam" thats what I think of.
Now for the $64,000 question; when someone in Canada says "Blue" what do you think of? /forums/images/graemlins/grin.gif

 

[PBinWA]

</font><font color="blue" class="small">( Now for the $64,000 question; when someone in Canada says "Blue" what do you think of? /forums/images/graemlins/grin.gif )</font>

Labatt's

Want me to PM you my address for the cheque (That's Canadian for check)? I'll assume that is in US Funds!