Effect of serviceability limits on optimal design of steel portal frames

Thanh Duoc Phan, James Lim, Tiku T. Tanyimboh, RM Lawson, Y. Xu, Steven Martin, Wei Sha

    Research output: Contribution to journalArticlepeer-review

    20 Citations (Scopus)


    The design of hot-rolled steel portal frames can be sensitive to serviceability deflection limits. In such cases, in order to reduce frame deflections, practitioners increase the size of the eaves haunch and / or the sizes of the steel sections used for the column and rafter members of the frame. This paper investigates the effect of such deflection limits using a real-coded niching genetic algorithm (RC-NGA) that optimizes frame weight, taking into account both ultimate as well as serviceability limit states. The results show that the proposed GA is efficient and reliable. Two different sets of serviceability deflection limits are then considered: deflection limits recommended by the Steel Construction Institute (SCI), which is based on control of differential deflections, and other deflection limits based on suggestions by industry. Parametric studies are carried out on frames with spans ranging between 15 m to 50 m and column heights between 5 m to 10 m. It is demonstrated that for a 50 m span frame, use of the SCI recommended deflection limits can lead to frame weights that are around twice as heavy as compared to designs without these limits.
    Original languageEnglish
    Pages (from-to)74-84
    Number of pages11
    JournalJournal of Constructional Steel Research
    Early online date15 Apr 2013
    Publication statusPublished - Jul 2013


    • Optimization
    • Hot-rolled steel
    • Portal frames
    • Niching
    • Real-coded GA
    • Serviceability limits

    ASJC Scopus subject areas

    • Building and Construction
    • Civil and Structural Engineering
    • Mechanics of Materials
    • Metals and Alloys

    Fingerprint Dive into the research topics of 'Effect of serviceability limits on optimal design of steel portal frames'. Together they form a unique fingerprint.

    Cite this