Newb Question How to Draw Special Joints

[dreber]

Hi All,

I am using SAP2000 16 to model a diaphragm.

My goal is to add point loads in the center of the plane and then constraining all of the joints on that rigid diaphragm.

I believe I should be using Special Joints.

I defined my grid system, and the location where the special joints is not along any members - they are just nodes in space. I can add the special joint, but the second I do anything else, it is automatically deleted.

Any idea how to accomplish what I am trying to do?

 

[SteeliestFire55]

I've come across something similar before.

Try this: Under 'View'>'display options'>'Miscellaneous'>'Show joints for objects in View'.
If the box is checked, that means that nodes that aren't connected to frames/areas etc will not be displayed. Special nodes will be visible momentarily but rotating/panning your view will cause them to disappear.

More importantly, I'd recommend meshing your diaphragm. In order for our point load to be applied to the diaphragm, the node needs to be connected to the shell.

 

[stressed]

Make sure under 'Set display options' that joints are not checkboxed to be "invisible", because the default is to hide joints from view. If you have an area, as SteeliestF said, make sure your area is meshed in order to include the special joint.

 

[dreber]

Thanks for your help, but no luck so far.

I have taken a bunch of screenshots in the event that it might clarify the problem.

1 - DISPLAY OPTIONS
First, this is a screen grab of my display options:

https://dl.dropboxusercontent.com/u/217910/SAP2000 Problems/1 - DISPLAY OPTIONS.jpg

2 - BEFORE ADDING NODE
Then, I grabbed a screenshot before adding any of the special joints

https://dl.dropboxusercontent.com/u/217910/SAP2000 Problems/2 - BEFORE ADDING NODE.jpg

3 - SPECIAL JOINT ADDED
Then, I add the special joint - everything seems to be working fine.

https://dl.dropboxusercontent.com/u/217910/SAP2000 Problems/3 - SPECIAL JOINT ADDED.jpg

4 - PANNING DELETES NODE
Then, after panning the slightest amount, the special joint is deleted.

https://dl.dropboxusercontent.com/u/217910/SAP2000 Problems/4 - PANNING DELETES NODE.jpg

 

[dreber]

-Solved

I'm not sure what happened, but it must have been a bug. It works as expected now.