The unique structure of wood requires a variety of testing methods to fully characterize the material properties. The specific end use application for the wood material also dictates which test methods are necessary to determine the strength. Tensile tests of wood are conducted parallel and perpendicular to the wood grain, using both large and small specimens.
Care must be taken when preparing wood samples for parallel testing to ensure that the growth rings, through the gage section, run parallel to the direction of force application. Elongation properties for parallel testing are measured using an extensometer on the wood specimen gage section, ensuring that only strain in the section with parallel grain is measured. Wood specimens for testing perpendicular to the grain are much smaller than parallel samples and generally do not require elongation data beyond what is given by test grip separation.
ASTM and ISO have created standard test methods for testing the various tensile properties of wood and wood based products. These test methods allow wood to be tested by a consistent method so that data can be accurately compared across different years, species, and manufacturing companies. Popular test standards are ASTM D143 for small timber specimens, ASTM D1037 for wood base fiber and particle panels, ASTM D3500 for structural panels, ISO 16984 for wood based panels, and ISO 3346 for regular wood.
Wood tensile test equipment selection can be highly dependent on the specific type of wood material being tested and the direction of testing. ASTM and ISO standards specify machine and grip requirements for each type wood tensile test method. The machine and grip families below can be configured to meet the ASTM and ISO requirements and TestResources application engineers can help you decipher the right solution for your test needs. For consultation with an applications engineer, contact us or call today!