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Slab Edge Releases

Slab Edge Releases

Slab Edge Releases

(OP)
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.

RE: Slab Edge Releases

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.

RE: Slab Edge Releases

(OP)

Quote (JoshPlumSE)


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

RE: Slab Edge Releases

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.

RE: Slab Edge Releases

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

RE: Slab Edge Releases

(OP)
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 .

RE: Slab Edge Releases

(OP)

Quote (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.

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 ?



RE: Slab Edge Releases

(OP)
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?

RE: Slab Edge Releases

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.

RE: Slab Edge Releases

(OP)

Quote (JoshPlumSE )


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

RE: Slab Edge Releases

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

RE: Slab Edge Releases

(OP)

Quote (sticksandtriangles)


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

RE: Slab Edge Releases

Quote (dccd)

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

RE: Slab Edge Releases

(OP)

Quote (sticksandtriangles)



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 ?

RE: Slab Edge Releases

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

RE: Slab Edge Releases

(OP)

Quote (sticksandtriangles)


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

RE: Slab Edge Releases

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

S&T

RE: Slab Edge Releases

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.

RE: Slab Edge Releases

(OP)

Quote (JoshPlumSE)

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 ?

RE: Slab Edge Releases

Quote:

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.

RE: Slab Edge Releases

Well, I put some more effort into my test last night and this morning. Line Releases are indeed internal.

I confirmed that I can just draw a line in the middle of a slab and assign my line release to that object to create an expansion joint. It turns out that I had a bad model (meshing constraints were not allowing my line release to get connected).

In my opinion, Line Releases seem a little trickier to work with than Edge Releases. However, they can be used to do similar things. And, I can imagine situations where they would be very useful.

RE: Slab Edge Releases

Caveat:
I actually work for CSI, the company that makes ETABS. I'm relatively new there and still learning some of their products. More accurately, I'm still learning some the advanced details of their products. This is why I got so interested in this thread. Because I wanted to really know the ins and outs of these two features and how they differ.

Long story short: On matters related to CSI products or their competitors, I cannot be expected to be a neutral party as I have some definite bias on the subject.

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