LRFD VS. ASD

Issued in 1986, the Load and Resistance Factor Design (LRFD) Specification is only now gaining a foothold in the design community. LRFD is based on an ultimate strength and reliability approach and is a more rational design procedure. The safety factors are comprised of load factors and strength reduction factors for different loadings, while the ASD (Allowable Stress Design) method uses a safety factor on the yield stress value to obtain an allowable stress. Examination shows that when design is based solely on strength considerations, LRFD is considerably more economical than ASD for office floor beams spanning 30 feet to 46 feet. A study is reported in which serviceability issues were investigated. The study results are tabulated. It was found that using LRFD results in beam sizes that are one or two sizes lighter than those obtained using ASD. Study results relating to dead-to-live-load ratios, load deflections, and vibration problems are discussed.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00268445
• Corporate Authors:

  American Institute of Steel Construction

  Wrigley Building, 400 North Michigan Avenue, 8th Floor
  Chicago, IL  United States  60611
• Authors:
  • CULP, T
  • Mathur, R
• Publication Date: 1991-11

Media Info

• Features: Tables;
• Pagination: p. 24-27
• Serial:
  • Modern Steel Construction
  • Volume: 31
  • Issue Number: 11
  • Publisher: American Institute of Steel Construction
  • ISSN: 0026-8445

Subject/Index Terms

• TRT Terms: Beams; Deflection; Design; Load and resistance factor design; Loads; Resistance (Mechanics); Safety factors; Ultimate strength; Vibration
• Uncontrolled Terms: Allowable stress design
• Old TRIS Terms: Load deflection
• Subject Areas: Bridges and other structures; Design; Highways; Safety and Human Factors; I20: Design and Planning of Transport Infrastructure;

Filing Info

• Accession Number: 00616616
• Record Type: Publication
• Files: TRIS
• Created Date: Nov 30 1991 12:00AM