Applies To
	Product(s):	STAAD Advanced Concrete Design
	Version(s):	Connect Edition
	Environment:
	Area:	Concrete Design
	Subarea:	Beam design
	Original Author:	SANJIB DAS Bentley Technical Support Group

If Beam is designed for axial plus biaxial forces, ideally if axial force in beam is less than the permissible value given in IS 13920 code, the member should be designed as beam only both for strength and crack width and check as per columns should not be applicable.

Whenever design for ‘Biaxial Bending’ is selected, RCDC would treat the design of beam like a column. There is possibility where axial forces would be negligible but lateral moment and shear would be high. In this case this member should be designed as a column only. Axial forces will not govern whether to details the member like beam or column.IS 13920 suggest to design/ details member like column as per clause 7 if axial stress exceeds 0.08ck. here the section will be detail as a column. shear (ductile) links should be calculated as per column. if axial stress less than 0.08 fck the section would be details as beam. All the links calculations would be as per beam. Further depending on Pu-threshold value set by user (the value is considered as compressive), RCDC will design the section with Pu, Mu-major and Mu-minor. If Pu for a given combination is less than Pu-threshold, it simply assumed, Pu = 0. This is only for ‘design combinations’ or limit state of collapse. For crack-width, there is no input for threshold value (currently there is no provision for it) of axial force. The crack-width is checked for service combinations. In this case, the values as per combinations are used for crack-width check.