The design philosophy and procedural logistics for member selection and code checking is based upon the principles of allowable stress design. Two major failure modes are recognized: failure by overstressing and failure by stability considerations. 

The following sections describe the salient features regarding the process of calculation of the relevant allowable stresses and the stability criteria being used. Members are proportioned to resist the design loads without exceeding the allowable stresses and the most economical section is selected based on the least weight criteria.  The code checking part of the program also checks the slenderness requirements, the minimum metal thickness requirements, and the width-thickness requirements.

The detailing requirements, such as provisioning of stiffeners and checking the local effects like flange buckling, web crippling, etc. must be performed manually. It is assumed that you are familiar with the basic concepts of Steel Design facilities available in STAAD.  Please refer to D. Steel Design for detailed information on this topic.