Unbraced Length of Truss Web Member

[Light1997]

I have Steel truss with top and bottom chord made of W Beams and Web Members are built up WT+Angle sections, the web member is connected via bolts to gusset plate at bottom flange of top chord and top flange of bottom chord. Can I use effective length from center to center of gusset plates or I can reduce it more, and what K factor I have to use, I know K=1.0 is conservative but I want to know actually what value of K I can use?

 

[dik]

Depending on the stiffness, it can be less... I generally use 0.9 or the clear distance for small web members... a caution though, I don't like tight designs for compression elements or cantilevers.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[KootK]

The answer may vary depending on what form of buckling your considering:

1) In the plane of the truss.

2) In a plane perpendicular to the truss.

3) Torsional.

 

[MotorCity]

If this is a new truss, I always use K=1.0. If I am checking or reinforcing an existing truss and trying to get it to work, I use K = 0.9 or the distance between gussets (assuming its all welded construction), but not both.

 

[Light1997]

Thanks @MotorCity!

 

[Light1997]

@KootK, I'm using it for in plane buckling.

 

[Light1997]

Thanks @dik

 

[rowingengineer]

I find the cidect manuals helpful, these were free from cidect website when I downloaded mine, might have changed these days. But the chapter that would interest you is attached, just search for effective length.

 

[Light1997]

Thank you this has been very helpful! @rowingengineer