Industrial facilities are highly dependent on pipe rack structures. AISC Specification for Structural Steel Buildings (AISC 360-10) is the most common method for analysis and design of these pipe racks. Improper application of stability analysis methods could lead to unconservative results and potential instability in the structure jeopardizing the safety of not only the pipe rack structure but the entire industrial facility.
There are three main methods for stability analysis on pipe rack structures.
The first order method typically provided conservative results.
The effective length method was determined to underestimate the moment demand in beams or connections that resist column rotation.
The direct analysis method was found to be a powerful analysis tool as it requires no additional calculations to calculate additional notional loads, calculate effective length factors or verify AISC 360-10 limitations.
Stability analysis is acceptable as long as limitations are met and the methods are applied correctly.