Quantcast
Channel: RAM | STAAD Forum - Recent Threads
Viewing all articles
Browse latest Browse all 23543

RE: Section Wizard Vs Section Profile

$
0
0

This is the answer to why four of the terms - shear area terms AY and AZ, and equivalent flange and web thickness terms TD and TB do not match in the comparisons that were done.

First, the shear area terms.

As I wrote in an earlier response, there are two modules in Section Wizard : Section Builder and Free Sketch

The Section Builder module does not have the capability to calculate the shear area. You can see this if you examine the properties report that Section Builder creates. Go to the Tools menu of that module and choose the first item which is Calculate. In that report, you will not find any terms called Shear Area.

So, when you ask for the properties of the section to be exported from this module to STAAD.Pro, a approximate set of AY and AZ are determined on the fly. Their values are 75% of the cross section area of that section. You can see evidence of this if  you look at the properties of the section named STARCOL in the input file called "COLUMN-SECTION WIZARD.STD" that Pawan attached. Notice that AX = 0.0654 sq.m, while AY = AZ = 0.04905 sq.m which is 75% of AX.

The Freesketch module on the other hand calculates the shear area. In STAAD.Pro, when you go to Tools - Create User Table - New Table - General - Add New property, and in the dialog box that comes up, choose the option for a section termed "Define Profile Polygon", the calculations that are performed are done using a very similar procedure to what is done by Section Wizard's Free Sketch module. Consequently, instead of using the Section Builder mode, if Pawan Waghmare had chosen the Free Sketch mode, he would have found the properties to be very similar to what he got in the model named "Column-Profile.std".

I have attached a Cruciform.cns file (that can be opened in Freesketch) for the model that Pawan created using the Section Builder mode.

(Please visit the site to view this file)

Regarding TD and TB : These terms come to life only when you export the data from Section Wizard to STAAD.Pro. They exist for only one reason, which is, they are a means by which the user can tell STAAD that his/her compound section can be approximated to an I-shaped section. The section dimensions of that I-shape are defined using the attributes D, B, TD and TB in addition to the derived properties like AX and IZ. The only way by which the program can come up with meaningful values for these is if you use the option called Find equivalent section, select the one called "Find equivalent wide flange beam" and export it to STAAD. It then comes into the User Table as a Wide Flange. If you simply create the compound section and export it to a General section, you will get some meaningless values for these terms that are based on some pre-determined rules instead of any scientific basis.


Viewing all articles
Browse latest Browse all 23543

Trending Articles



<script src="https://jsc.adskeeper.com/r/s/rssing.com.1596347.js" async> </script>