The mechano-sorptive creep susceptibility of two softwoods and its relation to some other materials properties

Abstract

This paper describes a new design of bending creep machine for accurate measurements of mechano-sorptive creep. Tests on two species of pine showed that at low stresses bending and tension gave similar results. It is shown that the mechano-sorptive creep susceptibility correlates with the mean microfibrillar angle of the S2 layer in a continuous relation that includes two species of pine, including one which showed evidence of compression wood; thus giving further evidence of the importance of inter-microfibril stresses in the S2 layer in mechano-sorptive creep. Accordingly, mechano-sorptive creep susceptibility also correlated continuously with elastic compliance; thus encouraging the possibility of the selection of non-susceptible material by machine stress grading. These two correlations also diminish the main obstacle to research on mechano-sorptive creep, the excessive variability of the material and the consequent difficulty of matching of samples.