Einfluss von Temperatur und Holzfeuchte auf die dynamischen Eigenschaften von unsortierten Fichtenbrettern | Influence of temperature and moisture content on the dynamic properties of ungraded spruce boards
2012
Unterwieser, Helene | Schickhofer, Gerhard
In order to draw conclusions concerning the sound velocity and the dynamic modulus of elasticity of logs and green timber at reference conditions, properties were determined for green timber at temperatures around and below the freezing point. The present investigation includes the analysis of the dependence of sound velocity and dynamic modulus on temperatures between −20 °C and +20 °C and on moisture contents below and above fibre saturation. Sound velocity and dynamic modulus of elasticity were determined based on natural frequency and density. Both sound velocity and dynamic MOE decreased linearly with increasing moisture content and increasing temperature below fibre saturation. Three temperature areas need to be considered above fiber saturation—below −5 °C and above 0 °C and the area between −5 °C and 0 °C. Sound velocity as well as dynamic MOE decrease linearly with increasing temperature. Based on these findings, appropriate adjustment functions for each moisture content and temperature range were found to calculate the dynamic properties at the reference conditions.
显示更多 [+] 显示较少 [-]