Shear flow

[danohl]

Hi all,

Is there a way to view the shear flow along edges in FEMAP? There is a function in the NEi editor called shear flow but I haven't seen it in FEMAP. It seems like a quite basic function and something that would be used all the time (welds, rivets etc).

Problem: I need to determine on a basic stage the amount of bolts required along the edge between two panels (3D shells) that are connected. I was first thinking of using the element force FX, FY to obtain a force/length but it gives me somewhat different values than from the shear flow plot in the NEi editor and the more I search on the subject the more confused I get.

Cheers,
Daniel

 

[trainguy]

I've used contour plots of FXY (shear force per unit length) and tried to get an average value along an edge.

You could also enable Grid Point Force Balance in the Analysis set manager, then use free-body plots to evaluate nodal forces at an interface.

tg

 

[rb1957]

element shear stress / element thickness ?

 

[trainguy]

rb,

Don't you mean

element shear stress * thickness

or,

element force / thickness

tg

 

[rb1957]

yes

 

[danohl]

Thanks for the feedback. Haven't really analysed joints this thoroughly before so please bear with me

Wouldn't FXY give only the shear component? I'm mostly worried about the normal force since the panels are mostly laterally loaded.

I think what I am really looking for (at this stage, initial design) is the actual in-plane force, principal or equivalent, since I know how much each bolt can take from analytical estimates.

Wouldn't the element load/length: FX and FY, plotted together as a combined vector give an indication on the amount of force the bolt line is subject to?

Daniel

 

[rb1957]

yes, if you have a joint you'll need to consider the shear in both directions (FX and FXY, or FY and FXY) as a vector.

 

[danohl]

Thanks, that makes perfect sense to me now.