Mechanical Properties of Dahurian Larch Wood under Cyclic Loading: Experiments and Constitutive Model

Abstract

This article presents a study on the mechanical properties and constitutive model of Dahurian larch wood under parallel-to-grain (ParG) and perpendicular-to-grain (PerG) cyclic loading. A total of twenty-four dog-bone specimens were designed and prepared. Failure modes, stress–strain curves, elastic moduli under monotonic loading, and unloading/reloading moduli under cyclic loading were analyzed. Results indicated that the tensile and compressive envelope curves of wood under cyclic loading are similar to the monotonic stress–strain curves. The unloading and reverse reloading stiffness of wood are significantly degraded in both material directions. Furthermore, a constitutive model that is capable of considering the degradation of cyclic compression unloading stiffness and the change in reverse compression (tension) stiffness after tension (compression) unloading was proposed. A comprehensive comparison with test results was conducted, and they are in good agreement. Thus, the correctness of the proposed constitutive model is verified.