Slenderness value on Lx and Ly verification, Steel Design Module Group Design

[Anonymous]

Hi Guys, I've been using robot for a couple of years now but this is the first time that I am using the steel module.

I have a model of a facade frame.

See below for Details:

I made the Glass as curtain Walls for it not to carry any load and force distribution is on the X-axis towards the frames. It is pin supported as in the picture. I used Wind Tunnel simulation in robot to create the wind loadings. LRFD2000 is used for verification.

During the verification process i noticed that there is no Lx and Ly input for verification. Lx and Ly are supposed to be the unbraced length of the Truss as per X and Y direction to figure out the Slenderness Limit. 

My questions are as follows:

1. Does Robot take the Lx and Ly based on how you draw the members?

2. Is there a way to modify Slenderness Ratio based on unbraced Length as perceived by the designer?

3. How can I automate design of this structure, by means of robot will be picking the sections for the Truss members as per weight limitations?

4. I have trouble using the Code Group Verification and Code Group Design. Please Help.

 

I also attach my file for verification purposes on your side.

Thanks. Hoping for a swift and immediate response.

[Artur.Kosakowski · Accepted solution]

1. Does Robot take the Lx and Ly based on how you draw the members?

Yes, as well as definition of positions of restrains (internal bracing option)

2. Is there a way to modify Slenderness Ratio based on unbraced Length as perceived by the designer?

You can set the limit after pressing the Configuration button. 

3. How can I automate design of this structure, by means of robot will be picking the sections for the Truss members as per weight limitations?

4. I have trouble using the Code Group Verification and Code Group Design.

Please look at the recording of the steel design webinar available from http://forums.autodesk.com/t5/robot-structural-analysis/robot-structural-analysis-webinars/td-p/5523...

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

[Anonymous]

---

3. How can I automate design of this structure, by means of robot will be picking the sections for the Truss members as per weight limitations?

4. I have trouble using the Code Group Verification and Code Group Design.

Please look at the recording of the steel design webinar available from http://forums.autodesk.com/t5/robot-structural-analysis/robot-structural-analysis-webinars/td-p/5523...

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

---

Soo here in the Code Group I will have to specify it one by one per member? The Webinar does not indicate how to select ro make a code group at one Click.

[Artur.Kosakowski]

I'm not sure if I understand you correctly but I hope this is what you need:

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

[Anonymous]

---

@Artur.Kosakowski wrote:

I'm not sure if I understand you correctly but I hope this is what you need:

---

I See... Thanks for this.

So to clarify things further, if you specify a group of bars for Group Design, Robot Will just pick the most Critical part on That Group and Design That, then i have an option to apply that in to group?

I noticed that the Group Design is not able to do SLS and ULS Design Simultaneously, is that normal? or Is this just a bug?

[Anonymous]

Another Thing, Why do nodes in my truss does not have any forces on it???

But members Has? Is there a way to Display Forces on Nodes? I will use this for Connection Design..

[napooil]

I thing. Node properties>reaction tab will display when you select node with support.

[Artur.Kosakowski]

So to clarify things further, if you specify a group of bars for Group Design, Robot Will just pick the most Critical part on That Group and Design That, then i have an option to apply that in to group?

Correct.

I noticed that the Group Design is not able to do SLS and ULS Design Simultaneously, is that normal? or Is this just a bug?

It is as designed. I would rub the group design for ULS, replace sections, run verification for ULS and SLS and decide if design for SLS should be done for the whole group or some of its elements separately. You may want to see the steel design webinar which shows this workflow.

http://forums.autodesk.com/t5/robot-structural-analysis/robot-structural-analysis-webinars/td-p/5523...

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

[Anonymous]

---

@napooil wrote:
I thing. Node properties>reaction tab will display when you select node with support.

---

Soo in my model, it is impossible to see the Node Reactions coming from the Members?

Yes I can see the forces on the Nodes with Supports but Nodes that are connected to elements does not have forces in it. Much Like when we do manual calcs, using method of joints we have forces in the joints(nodes)??

Soo robot uses method of Members I guess?