Compare EN 383 and ASTM D5764 on the embedment properties of plywood: Influence of test setups, specimen geometry, and loading procedures

The proper design of timber connections requires precise characterization of the embedment strength and stiffness values. Valid embedment data are usually sourced from experiments following different testing standards. However, these values have been known to be influenced by discrepancies among different test standards, making it challenging to compare available embedment test data from various literature sources and use these values in predicting the strength and stiffness of connections. Therefore, it is essential to investigate and understand the differences among embedment test standards, of which EN 383 and ASTM D5764 are the two most representative ones. In this study, embedment tests on nearly 200 specimens were conducted following specifications in EN 383. First, the loading procedures, specimen configurations, and orientations slightly varied among different test series, so the significance of certain subtle parameters within EN 383 was examined. Second, the measured values were compared with the literature data tested following ASTM D5764. Thereby, by considering the difference in veneer layups, the reduction factor for plywood was analytically derived based on the formula for LVL as recommended in Eurocode 5. A combined formula was thereby derived to predict the in-plane anisotropic embedment strength values and compared with the experimental embedment data. • EN 383 embedment experiments were conducted on almost 200 birch plywood specimens. • An innovative embedment test setup, EN 383 half-hole embedment test, was proposed. • The significance of loading parameters in EN 383 was depicted and discussed in detail. • Embedment properties measured according to EN 383 and ASTM D5764 were compared. • An analytical formula for plywood derived based on veneer layups and Eurocode 5.