A METHOD OF TESTING THE FULL CROSS-SECTION OF WOOD IN TENSION PERPENDICULAR TO THE GRAIN

This report describes a method of testing wood specimens in tension pe rpendicular to the grain whereby the entire cross section of the wood may be subjected to stress. This method makes it possible to use tensi on perpendicular testing to detect internal tree damage such as ring s eparation through the entire radius of the tree. The testing procedure is performed on a solid 2- by 2-inch variable-length test specimen. T ensile stress is transferred to the test specimen through hard maple b locks that are glued to the pith and bark faces of the test specimen. The work was prompted by a study of storm-damaged trees in the Francis Marion National Forest. 1 As part of the study. sections were removed from 60 tree stems. A total of 273 specimens were tested. Tensile str ength and break location were the primary variables of interest. Altho ugh the results show no conclusive evidence of internal damage. the te st may be a useful alternative to the standard ASTM D 143-83 for full cross-section testing of tension perpendicular to the grain.