YoungTurk
Mechanical
- Jul 16, 2004
- 333
Hello All,
Here's a simple beam problem that just doesn't sit right with me. I have a thin, flexible beam, a strap really, fixed in the center and loaded on each end. The ends are restrained such that the end to end distance can be idealized as fixed.
Analyzing the beam as "perfectly flexible" per Roark table 8.10 case 5 gives tremendous tension in my "cable" relative to the transverse load. Since in reality my strap is riveted at the ends, this results in very high analytical shear stress in my rivets (33X tranverse load in this case).
On the other hand, pure beam flexure theory gives extraordinary deflection and doesn't allow one to derive axial loads (and hence rivet shear) at the beam ends.
My mentor has implemented the flexible beam theory, but the rivets required just seem excessive. What, if anything, am I missing? Is there a generally accepted solution which captures both the tensile and bending behaviors?
I have discussed this one a bit around work and looked through a few handy references to no avail.
Here's a simple beam problem that just doesn't sit right with me. I have a thin, flexible beam, a strap really, fixed in the center and loaded on each end. The ends are restrained such that the end to end distance can be idealized as fixed.
Analyzing the beam as "perfectly flexible" per Roark table 8.10 case 5 gives tremendous tension in my "cable" relative to the transverse load. Since in reality my strap is riveted at the ends, this results in very high analytical shear stress in my rivets (33X tranverse load in this case).
On the other hand, pure beam flexure theory gives extraordinary deflection and doesn't allow one to derive axial loads (and hence rivet shear) at the beam ends.
My mentor has implemented the flexible beam theory, but the rivets required just seem excessive. What, if anything, am I missing? Is there a generally accepted solution which captures both the tensile and bending behaviors?
I have discussed this one a bit around work and looked through a few handy references to no avail.