LAUSR

Abstract Softwood is commonly used in timber structures, whose dynamic compressive properties along the grain direction under seismic rate actions are of major concern. In the present study, 108 samples were examined from three species of softwoods (spruce, Dahurian larch and pine) and subjected to four levels of strain rates (10−4 s−1, 10−3 s−1, 10−2 s−1 and 0.1 s−1) under parallel-to-grain monotonic and repeated compression. The seismic strain rate effects on softwood were investigated by observing the failure mechanisms, engineering stress-strain curves, initial crushing strength, elastic modulus and peak strain. Results demonstrated the high sensitivity of softwood to seismic strain rates. Finally, a rate-dependent constitutive model was developed to predict the stress-strain relationship (both monotonic and repeated loading cases) of softwood under different seismic strain rates.