No, the members in a frame carry moments; truss members do not.
> Can method of sections, or joint equilibrium be used in analyzing
You can try but it's a statically indeterminate.
For a rough approximation, you could treat the members as
trusses (carry axial loads only) and analyze the structure.
But this could be off a lot, so be warned.
A frame CAN be modeled as a truss.
However it cannot be accurately modeled as a truss since a frame takes axial
AND bending loads where a truss ONLY takes axial loads.
What are you trying to do?
On 9 Feb 2004 08:41:52 -0800, aol email@example.com (O'neil Coleman)
Hmm...three people all sounding helpful, but coming up with different
approaches. Pehaps this note from UFlorida mentioning a truss
member in two dimensions will help to extend the idea of axial loads
A space frame is by definition three dimensional. Each element is
desired to take compression and tension forces only. The ensemble is
meant to offer a path for loads and torques
A previous poster (Bob K) had it right. To expand on his comments, a space
*frame* is a three-dimensional structure constructed with rigid connections.
Thus, deformations under applied loads will induce combined bending and axial
loads in the individual members. A space *truss* is a three-dimensional
structure constructed with pinned connections. In this case, the members will
carry only axial loads.
In years gone by (that is, when computer time was very expensive), structural
engineers commonly analyzed frames as trusses and then applied various rules of
thumb to estimate the moments in the members. By today's standards of
practice, one must analyze a frame as a frame. The means to do so are now
readily available to virtually all practicing engineers.
David Duerr, P.E.
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