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  #46  
Old 01-07-2017, 02:36 PM
JamesG123 JamesG123 is offline
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Quote:
Originally Posted by upchurchmr View Post
I beg to disagree - most people I know miss the actual point of a discussion, engineers are just really single minded about it.
As exhibited here.
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  #47  
Old 01-07-2017, 02:43 PM
JamesG123 JamesG123 is offline
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Originally Posted by Barry View Post

Of course stress concentration can be quite high at the roots of the thread and if the bolts design criteria is to resist mainly tension, this stress concentration is often the most significant design parameter
Which was the point of my post and analogy to a bolt. The foam in a sandwich composite structure, is of course under load, but the stresses are concentrated in the skins and the bonding between the foam and skin, so arguing about the foam indicates either; one doesn't really understand the engineering, they missed the point, or are just picking a fight.
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  #48  
Old 01-07-2017, 03:58 PM
TANSL TANSL is online now
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Quote:
Originally Posted by JamesG123 View Post
but the stresses are concentrated in the skins and the bonding between the foam and skin
That is not right. The stresses, in pure bending, are distributed throughout the thickness of the sandwich.
Quote:
Originally Posted by JamesG123 View Post
so arguing about the foam indicates....
I, at least, am not "arguing about the foam". What I have said from the beginning is that the foam can be used but that the tension/compression it is able to withstand is very low compared to other materials. Therefore, I would never use it as a structural element. Another problem is that, by better supporting the shear stresses, it can be used (although I would not) as material for the core of a sandwich panel and, above all, as the core of a top hat profile.
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