Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Re: Timber Truss Gusset Plate

[Subject Prev][Subject Next][Thread Prev][Thread Next]
I would agree that the joint is in equilibrium, and
that the axial member forces are resolved into their
respective vert and horiz components.  So, no, there
should be no/minor perp-to-grain forces on the bottom
chord for example...  I would then to think that the
first quarter undergrad lectures in Statics should be
true.  Otherwise, why would the method of joints be
taught???
David Topete, PE
SF, CA

--- Rich Lewis <sea(--nospam--at)lewisengineering.com> wrote:

> I am designing a timber truss using Parallam lumber.
>  The panel points
> are connected with steel side plates and bolts.
>  
> I have a question as to how I see the bolted
> connection designed.  I
> analyzed the truss with a frame analysis program and
> I have all the
> member forces for various load combinations.  I
> modeled the web members
> as pinned ends and the top and bottom chords as
> continuous members.  As
> I see the joint connection design I design the
> number of bolts based on
> the member forces.  The forces in the members are
> primarily axial forces
> so the bolts are designed based on parallel to grain
> values.  The top
> and bottom chords have some minor shear due to the
> continuous modeling.
>  
> Let me see if I can explain this further.  I will
> illustrate this with a
> specific joint, a bottom panel joint that has the
> bottom chord
> horizontal on either side, a diagonal going up to
> the top chord and a
> vertical going up to the top chord.  The force from
> the diagonal goes
> into the steel plate.  The vertical component of the
> force is resisted
> by the vertical web and the horizontal component is
> resisted by the
> bottom chords.  The force is distributed to these
> members through the
> gusset plate.  As I see it I don't have any
> perpendicular to grain
> forces in the bottom chord (except the minor shear
> forces) or the
> diagonal or the vertical.
>  
> I need a sounding board to bounce my thoughts off
> of.  Am I looking at
> this correctly?  Would this plate put a twisting
> force in the joint that
> will put perpendicular to grain loading in the
> bottom chord?  Would
> joint equilibrium negate this possibility?
>  
> Thanks for your help.
>  
>  
> Rich Lewis
> Lewis Engineering
>  
>  
> 



		
__________________________________ 
Do you Yahoo!? 
All your favorites on one personal page ? Try My Yahoo!
http://my.yahoo.com 

******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at: http://www.seaint.org/list_FAQ.asp
* 
*   This email was sent to you via Structural Engineers 
*   Association of Southern California (SEAOSC) server. To 
*   subscribe (no fee) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you 
*   send to the list is public domain and may be re-posted 
*   without your permission. Make sure you visit our web 
*   site at: http://www.seaint.org 
******* ****** ****** ****** ******* ****** ****** ********