The Effect of the Rate of Longitudinal Compression on Selected Wood Properties

Abstract

Abstract Longitudinal compression of wood and relaxation after compression (held compressed for a while) is called pleating and results in improved bending properties. The examinations conducted on the longitudinal compression of air-dried oak (Quercus petraea (Matt.) Liebl.) and beech wood specimens (Fagus sylvatica L.) revealed the effects of different compression rates (10, 20, 40, 60 mm/min). The comparison of the various treatment methods showed that the stress in wood specimens during longitudinal compression increases with the rising compression rate. The remaining length reduction due to pleating slightly decreases and the bending modulus of elasticity increases at higher compression rates. The highest deflection of the specimens during the 4-point bending tests lowers with the increasing compression rate, while the change of modulus of rupture is negligible. Taking into account the differences between these results and the industrial effectiveness of the treatment according to the compression rates, it can be stated that a procedure with a higher rate should be preferred.