supplemental modules

These modules were developed to enhance your understanding of wood as an engineering material and to illustrate analysis and design techniques applicable to timber structures.

  • Moisture Effects   -- Wood is a natural, fibrous material, and it gains or loses moisture as changes occur in the temperature and humidity of the surrounding air.  For example, lumber located in a cool humid climate would tend to have a higher moisture content than if the climate was warm and dry. This ability of wood to absorb or exude moisture is important in wood design since moisture content affects the structural properties of wood.
  • Wind Loads -- The objective of this module is to provide an introductory exposure to the estimation of wind loads and the associated structural behavior of low-rise wood buildings.  Load development is based on the 1997 version of the Uniform Building Code.
  • Lumber Production -- A thorough knowledge of the fundamental physical and mechanical properties of a material is a prerequisite to the proper use and application of the material.   Additionally, an understanding of the manufacturing and processing of the material is needed.  This module introduces the manufacturing and visual grading processes commonly used for solid sawn lumber.
  • Load Duration Factors  -- Duration of load is the total cumulative length of time that the full design load is applied to a wood member.  Load duration factors address the ability of wood to resist higher stresses when loads are applied for a short period of time.   Load duration is one of the least understood attributes of wood by practicing engineers, yet it plays a key role in the overall design of wood structures.
  • Adjustment Factor Quiz -- After determining which adjustment factors are applicable to a design, the designer must select a tabulated design value and adjust it appropriately.  This module provides several self-guided quizzes regarding application of adjustment factors.
  • Adjustment Factor Scenarios  -- One of the unique aspects of wood design is the need to adjust tabulated design values for expected end-use conditions.  Factors to consider include moisture content, temperature, duration of load, etc.  This module provides numerous practice scenarios where you are asked to determine the appropriate design values and adjustment factors needed for design.
  • Beam Design --The purpose of this module is to illustrate the effects of load and span on beam design. In particular, the relationships between beam span and various limit states (shear, moment, and deflection) are emphasized.
  • Connections -- Laterally-loaded connections in wood structures are designed based on a series of "yield limit equations" when fasteners such as bolts, lag screws, wood screws, or nails are used to transmit loads in shear.  An understanding of how various material and geometric factors affect connection design is critical to the design process.
  • Dowel Bearing Strength -- Dowel bearing strength (Fe) is the crushing strength of wood in contact with a fastener. This strength property influences the nominal design value (Z) for connections that employ bolts, nails or other fasteners to resist loads in wood structures.
  • Shear Walls --  This module illustrates the lateral load path through a typical wood structure and describes two design methodologies for wood-frame shear walls.   The use of code-specified Allowable Shear Design Tables for wood-frame shear walls is also illustrated.
  • Diaphragms --  This module illustrates the design methodology for wood-frame diaphragms that resist lateral loads in structures.
  • Seismic Loads --  The objective of this module is to provide an introductory exposure to the estimation of lateral seismic loads and the associated structural behavior of low-rise wood buildings. Load development is based on provisions of the 2000 International Building Code (IBC) and the 1997 Uniform Building Code (UBC).
  • Shear Connections --  The objective of this module is to display a graphical reprensentation of load versus displacement as a shear connection is loaded to failure.
  • Span Calculator for Joists and Rafters -- Interactive calculator for determining maximum allowable spans for sawn lumber floor joists, ceiling joists, and rafters. Calculations address lumber bending capacity, shear capacity, bearing capacity (at ends of members), and deflection.


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Updated: 02/13/04
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