Embedment strength of wood perpendicular to the grain: comparison of test methods

Abstract Connections are the points with higher stress concentrations in wood structures. For the design of this fasteners two parameter are used: tensile strength of the steel and the embedment strength of the wood member. The aim of this study was to compare the testing methods and design criteria of different normative documents (NBR 7190, EN 383, ASTM D-5764, EUROCODE 5 and NDS) to determine the wood embedment strength perpendicular to the grain. Six species of wood (Schizolobium amazonicum, Pinus elliottii var. elliottii, Pinus oocarpa Shiede, Hymenaea sp, Lyptus (Eucalyptus grandis/Eucalyptus urophylla) and Goupia glabra and four metal dower diameters (8 mm, 10 mm, 12 mm and 16 mm) were used in the tests. In all cases, the average value of the experimental results of embedment strength to the grain obtained from the EN 383 standard were the highest; the limit slip of 5 mm between metal dowel and wood member never was reached in tests performed according to this standard. The experimental results obtained in this case presented good agreement with the values calculated according to the design criteria of NBR 7190. It was not possible to carry out the tests according to the NBR 7190 method because of the difficulty to obtain the dimensions required for the specimen in perpendicular direction.