Effects of ring characteristics on the compressive strength and dynamic modulus of elasticity of seven softwood species

The effects of ring characteristics on the compressive strength and dynamic modulus of elasticity of seven softwood species were examined. The results revealed that there is a good correlation between compressive strength and dynamic modulus of elasticity obtained by using an ultrasonic wave technique (with correlation coefficients r = 0.77–0.86). As a whole, values of compressive strength increased with decreasing ring width parameters; however, they increased with increasing ring density parameters. The ring density related to the compressive strength, but it is not the sole factor affecting strength of wood. According to our statistical analysis, compressive strength was affected by various ring characteristics. The relationships between ring characteristics and compressive strength are influenced by the anatomical directions longitudinal, radial, and tangential. Results revealed that earlywood density and minimum density in a ring are equally important variables for evaluating compressive strength of wood.