Effect of grain orientation on the energy absorption performance of Chinese fir wood under quasi-static compression

Abstract

ABSTRACT The compressive response and energy absorption of Chinese fir wood with different grain orientations along the longitudinal (L) and radial (or tangential) directions were studied through uniaxial quasi-static compression tests. The results indicated that the wood compressive behavior changed from out-of-plane to in-plane, similar to honeycomb materials when the grain orientation was changed from longitudinal to transverse. The initial peak stress (σp ) and plateau stress (σpl ) decreased upon increasing the grain angle (θ), especially below 45°, and more slowly above 45°. The wood compressive failure modes and energy absorption ability were also strongly dependent on the grain orientation, and the energy absorption per unit volume and energy absorption efficiency decreased as θ increased. Energy absorption diagrams and mathematical models were established to evaluate the optimum energy absorption point to guide the selection of energy-absorbing wood.