What is the best way to define DJ1 and DJ2 in STAAD?

[kk88818]

Hi everyone,

I have got a question of defining DJ1 and DJ2 in STAAD? As you might know, DJ1 (start node) and DJ2 (end node) are used in conjunction with the deflection (DFF) command in calculating beam deflection. Beams in STAAD are very often made up of multiple members, and DJ1 and DJ2 are used to inform STAAD what are the start and end nodes, and what members are there between the nodes. For example, if one of my beams consist of members 13, 45 and 56 and the start and end nodes are 6 and 89, respectively, I specify:

DJ1 6 MEMB 13 45 56
DJ2 89 MEMB 13 45 56

I do this manually, opening up my model and locating the beams and the respective node and member numbers. Now my question is, what if I have a huge model with hundreds, if not thousands, of nodes and members and I need to check the beam deflection for all of them.

What is the best way to define DJ1 and DJ2 in the case mentioned? I do it manually now and it literally takes hours and I can make many mistakes in input due to the tedium and wearniness involved. Hope someone can help.

Thank you so much.

kk88818
"When I can help, I do;
When I need help, I ask;
Sharing helps everyone
Understand so much better."

 

[SteveGregory]

Try setting up a spreadsheet to represent the input file lines needed to describe these nodes and member numbers. Then copy and paste or export a text file to insert this into your STAAD input file.

 

[kk88818]

Thanks SteveGregory,

Setting up a spreadsheet and then inputting the node and member numbers for the respective DJ1 and DJ2 is a good idea, and I sure would give it a go. It is still a form of "manual inputting" although it is done with a spreadsheet that is then imported into STAAD, and can be quite tedious if the model has a few hundred members, for example. That type of model is not unusual in STAAD. Anybody has any other suggestions inputting values for DJ1 and DJ2 using a mixture of GUI or Input file, for instance? What has been best technique so far for those who have done this before? Thanks again.

kk88818
"When I can help, I do;
When I need help, I ask;
Sharing helps everyone
Understand so much better."

 

[SteveGregory]

You may not have to input all the node numbers and member numbers if you can establish a starting number and an increment. Then copy each row of formulas and let Excel do the dirty work. For example:

cell A1 text: DJ1
cell B1 node number: 8
cell C1 text: MEMB
cell D1 member number: 485
cell E1 member number formula: = D1 + 15
cell F1 member number formula: = E1 + 22

on the next row...
cell A2 text: DJ1
cell B2 node number formula: = A1 + 49
cell C2 text: MEMB
cell D2 member number: = D1 + 33
cell E2 member number formula: = D2 + 15
cell F2 member number formula: = E2 + 22

Now copy row 2 down as much as required

 

[niiarmahstruct]

Hi

You probably should explore using the interactive steel design module of Staad Pro. You will have to define physical members for all the beams that you want to check deflection for before you run the analysis. Staad interactive Steel design is able to check for slenderness, deflection and a whole range of checks and present calculation results for you.

Hope this helps you.