Improved Frame Stability Analysis with Effective Lengths

摘要: Approximate methods for determination of effective lengths compression members in frame systems are normally based on rotational restraints defined through so-called joint stiffness ratios or G -factors. These approaches allow the member to be considered isolation from rest frame. However, they known inaccurate many cases. A method is proposed that involves postprocessing isolated column analyses arrive at improved, weighted mean values. The approach, termed means, satisfies general system instability principles, attractively simple, and yields length predictions excellent agreement with exact results a wide variation parameters. errors within few percent solutions. applicable braced range unbraced frames. It particularly suitable cases where drastic changes beam occur, such as top bottom stories fra...