ANOTHER LOOK AT LOAD DURATION EFFECTS IN WOOD

Load duration behavior, arising from creep rupture, is one of the most significant effects distinguishing wood from various other structural materials. Experimental research has focused on duration-of-load (DOL) effects in full-size lumber and a number of different cumulative damage models have been proposed. These models have been used in reliability analyses that consider the stochastic nature of the loading process to evaluate appropriate load duration adjustment factors for use in design. Recently, the stochastic damage accumulation process itself has been studied. This has resulted in proposals for simplified cumulative damage analyses and the re-emergence of the "killer pulse" concept for load duration effects in wood. The evolution of the new LRFD standard for wood provides a good opportunity to revisit this important issue. This paper briefly reviews DOL research, with particular emphasis on the work used as the basis for the time effects factors in the LRFD standard, and describes a simplified approach to cumulative damage analysis using order statistics. It is shown that reliability analyses including DOL behavior can be performed more simply using an order statistics approach or a simple first order reliability method analysis. Thus, it may be possible to evaluate load duration factors for design without having to perform complex stochastic cumulative damage analyses.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/07339445
• Corporate Authors:

  American Society of Civil Engineers

  1801 Alexander Bell Drive
  Reston, VA  United States  20191-4400
• Authors:
  • Rosowsky, D V
  • Bulleit, W M
• Publication Date: 2002-6

Language

• English

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 824-828
• Serial:
  • Journal of Structural Engineering
  • Volume: 128
  • Issue Number: 6
  • Publisher: American Society of Civil Engineers
  • ISSN: 0733-9445
  • Serial URL: http://ascelibrary.org/loi/jsendh

Subject/Index Terms

• TRT Terms: Bridge engineering; Creep properties; Highway engineering; Lumber; Statistical reliability; Structural deterioration and defects; Structural engineering; Structural materials; Wood structures; Wooden bridges
• Uncontrolled Terms: Creep rupture; Load duration
• Subject Areas: Bridges and other structures; Data and Information Technology; Design; Highways; I24: Design of Bridges and Retaining Walls;

Filing Info

• Accession Number: 00925069
• Record Type: Publication
• Files: TRIS
• Created Date: May 29 2002 12:00AM