Slab Edge Releases 1

[dccd]

Guys, may i know how to assign slab edge release in SAFE ? I have exported the model from ETABS into safe to design the slab.

Say that I want to release the edges at the yellow junction only. How to do this ? When I choose slab edge release in SAFE , it automatically release at 4 slab edges , which I dont want. I only want to release moment at certain edge only.

 

[JoshPlumSE]

All you should have to do is select the edge you want to release (and only that edge), then use the Assign - Slab - Edge Release command.

My guess is that you're selecting the whole slab instead of just the edge you're interested in.

 

[dccd]

That doesnt work. By selecting slab edge release command , 4 edges become discontinuous, I only want specific edges to be released.

 

[JoshPlumSE]

Huh, it works for me, but I have to be careful to only select a single edge and not the entire slab.

Note: I'm using the Standard Graphics, not the DirectX graphics mode. When I switch to direct X, I can't always tell if an edge is selected or not.

 

[Agent666]

The other way I seem to remember you can do it is to release it based on an intersection with a line element. Draw a null line and try it that way.

https://engineervsheep.com

 

[dccd]

I have use the slab edge release and line line release to release the moment at slab edge. However, zero stiffness error popping up. Why ? If I dont release anything to the slab, no error popping up .

 

[dccd]

Huh, it works for me, but I have to be careful to only select a single edge and not the entire slab.

Note: I'm using the Standard Graphics, not the DirectX graphics mode. When I switch to direct X, I can't always tell if an edge is selected or not.

Sorry to revive this thread. I found your method worked somehow. However, is there any better way than this ? Becuase in as you showed in teh diagram, the selected line (shown in green) is barely visible. I have used draw a line and try to release the slab edge moment using the line released command, sadly it doesnt work ... Do you know why ?

 

[dccd]

I will be exporting the slab to SAFE from Etabs to design the slab only. Is it necessary to assign slab release in Etabs or I can just do it in Safe since I use the Etabs to design beam and columns and SAFE for slab design only... Does it affect the results of beam much in Etabs if I doesnt assign slab release properly in Etabs?

 

[JoshPlumSE]

dccd -

I agree that the line can be difficult to see sometimes. It's probably worse for people who have a tiny bit of color blindness.

Sometimes it helps me when I vary the graphics mode from Standard to Direct X or such. Sometimes it helps when I look at it in a different view (plan vs 3D). Or, maybe if I switch from a white to a black background.

 

[dccd]

Thanks for your reply, there's no better way to assign the release on slab edge ? What's the purpose of line release ? I have tried to assign it in the system, I found it doesnt work most of the time, it seems that it's more appropriate to use elsba edge release

 

[sticksandtriangles]

dccd,

I like to change the colors of slabs from the dull grey default to any color of your choice. I picked orange and feel like the selected edge "pops" a little more.

Also, removing constant line thickness makes the line really pop:

S&T

 

[dccd]

Thanks for the suggestion, do you know the differenece between line release and slab edge release ?

 

[sticksandtriangles]

do you know the differenece between line release and slab edge release ?

Sorry, I do not. I have never used the line release feature; only the slab edge release.

S&T

 

[dccd]

Sorry, I do not. I have never used the line release feature; only the slab edge release.

I am referring to this, is this slab line Release similar to edge release ?

 

[sticksandtriangles]

Just so we are on the same page, I am referring to this button, slab edge release:

Releasing the moment and shear about the edge in image above yields shear and moment results that I would expect for a typical strip.

Shear:

Moment:

make sure you only select one edge when using this button.





S&T

 

[dccd]

Yes, I am aware of this... Just like to know the difference between line release vs slab edge release....

 

[sticksandtriangles]

I am not aware of a line release button, can you post a screen shot of the button you are referencing?

S&T

 

[JoshPlumSE]

Personally, I've only used the Slab/Shell Edge releases. These are applied to one of the edges of a slab object.

Line objects, on the other hand, are INTERNAL to an individual slab. Maybe you've already built a model and realize you have to put an expansion joint or something in the middle. Rather than deleting your slab and such, it's probably easier to add a line release.

I still tend to prefer the edge release since I like to have a little more control.

 

[dccd]

Maybe you've already built a model and realize you have to put an expansion joint or something in the middle

Do you mean instead of drawing 2 slabs and assign slab edge release at the joint expansion location , we can use draw a line on slab where the joint expansion location is and assign line release ?

 

[JoshPlumSE]

Do you mean instead of drawing 2 slabs and assign slab edge release at the joint expansion location , we can use draw a line on slab where the joint expansion location is and assign line release?

That was my impression. For kicks and giggles I tried it out a bit today and I had trouble getting it to work the way I thought it should. It definitely works when I have a beam at the edge of a slab and I assign the line release to the beam. But, getting it to work on the interior of the slab is a little trickier.

I'll give you an update if I figure out more precisely how it's supposed to work.