The start of the second century of the skyscraper also marks the introduction of Load and Resistance Factor Design (LRFD) as a new structural standard for steel design in the United States. LRFD follows a worldwide trend toward Limit State Design (LSD). The aim of structural standards is to provide for reliable structures. Specification and standards committees combine the results of research, structural analyses, and engineering judgment in establishing structural standards. With LRFD it is possible to exercise much better judgment than is possible with conventional Allowable Stress Design (ASD). Whereas ASD depends on a single material factor of safety, LRFD uses several load and resistance factors that recognize the levels of uncertainty associated with different types of loading and with approximations inherent in specification formulas. Judgment is further enhanced by statistical analysis of load and strength data so that numerical values can be established for the reliability index.
KeywordsResistance Factor Load Combination Structural Standard Target Reliability Index Limit State Design
Unable to display preview. Download preview PDF.
- Galambos, T. V. and Viest, I. M., 1985 DESIGN OF STEEL STRUCTURES WITH LOAD AND RESISTANCE FACTOR DESIGN SPECIFICATIONS, IABSE Reports, Vol. 48, Zurich.Google Scholar
- Peshek, Jr., C., 1978 THE AISC QUALITY CERTIFICATION PROGRAM, Engineering Journal, AISC, Vol. 15, No. 3, Chicago, pp. 102–107.Google Scholar
- Rolfe, S. T. and Barson, J. M., 1977 FRACTURE AND FATIGUE CONTROL IN STRUCTURES, Prentice-Hall, Inc., Englewood Cliffs, p. 129.Google Scholar