Composite Deck

Question

Dear Friends, 
 STAAD considers the effect of concrete-slab in the calculations of member's stiffness which are a part of a composite deck, but what if some of these members which define the composite deck area need to be free and to exclude the concrete deck from stiffness calculations.

Rgards,

Sye · Accepted Answer

You can always manipulate the composite deck data using the input command file. For example if you would like to declare the beam 503 as non-composite, you can just delete that member number from the member list accompanying the COMPOSITE parameter and also comment out the related CW parameter as shown next

Sye · Answer

Just as you can take out a beam from the list of composite members and take out the corresponding CW parameter to get the software to design it as a non-composite section, likewise you may add beams to the composite list and add corresponding CW parameters for those so that these are designed as composite beams. It has to be done following the same process as mentioned in my last post.

Sye · Answer

Since you are manipulating the deck parameters, these may get wiped out depending on what changes you are making to the model. What you can do is, keep a copy of the COMPOSITE and the CW command lines and once you are done making all the other changes, replace the current commands by the lines you copied earlier. Weight of the concrete above the flute is considered for selfweight calculation. The portion within the rib is ignored. You can manually apply the additional load.