Topic outline

  • Mechanical Properties of Wood

    Credits: 4 PDH

    PDH Course Description:

    The mechanical properties presented in this course were obtained from tests of small pieces of wood termed “clear” and “straight grained” because they did not contain characteristics such as knots, cross grain, checks, and splits. Many of the mechanical properties of wood tabulated were derived from extensive sampling and analysis procedures. These properties are represented as the average mechanical properties of the species. Variability, or variation in properties, is common to all materials. Because wood is a natural material and the tree is subject to many constantly changing influences (such as moisture, soil conditions, and growing space), wood properties vary considerably, even in clear material. This course provides information, where possible, on the nature and magnitude of variability in properties.

    Also included is a discussion of the effect of growth features, such as knots and slope of grain, on clear wood properties. The effects of manufacturing and service environments on mechanical properties are discussed, and their effects on clear wood and material containing growth features are compared.

    Topics:

    • Orthotropic Nature of Wood
    • Elastic Properties, Modulus of Elasticity, ,Poisson’s Ratio, Modulus of Rigidity
    • Strength and Vibration Properties
    • Common and Less Common Properties
    • Mechanical Properties of Clear Straight-Grained Wood
    • Natural Characteristics Affecting Mechanical Properties
    • Specific Gravity
    • Knots, Slope of Grain, Annual Ring Orientation, Pitch Pockets, Bird Pecks
    • Reaction Wood, and Juvenile Wood
    • Compression Failures
    • Properties of Timber From Dead Trees
    • Effects of Manufacturing and Service Environments
    • Moisture Content , Temperature, Time Under Load, Aging
    • Exposure to Chemicals, Chemical Treatment
    • Nuclear Radiation
    • Mold and Stain Fungi, Decay, Insect Damage

    To take this course:

    1.) Enroll in Course: Click below to enroll:
    (must be logged into your user account)


    2.) Study: Once enrolled, click below to begin the course:

    Download the Study Guide

    3.) Test: Once you've thoroughly read the course materials, please click below to take the final examination.

    Take the final exam

    4.) Certificate: A passing grade of 70% or higher on the exam, is required to receive the certificate of completion for this PDH course.
         NOTE: After the exam is completed, you will need to return to this page, in order to print (download) the certificate of completion.

    Print the Certificate of Completion

    Intended Audience: for this course are energy, mechanical, electrical, construction, and civil engineers. However, this course could appeal to engineers of other disciplines as well.
    Publication Source: US Dept. of Agriculture (Forest Service)

    Mark Rossow PhD, PE (retired)

    • Topic 1