Relationship betweeen timber grade, static and dynamic modulus of elasticity and SilviScan properties for Pinus radiata in New South Wales

Wood stiffness, or modulus of elasticity, can be measured or predicted using a variety of methods including standard bending tests, machine stressgrading, stress wave methods, or analysis of X-ray diffraction data from SilviScan. Each of these methods was applied to the same wood samples and the inter-relationships were determined. Dynamic modulus of elasticity (MOE) values from stress wave and SilviScan methods produced very similar results but both these methods produced higher values than the static modulus of elasticity from the traditional bending test. Results from all methods were highly correlated and simple regression equations were developed for converting results between methods. Machine stress-grade was more strongly related to SilviScan modulus of elasticity than to either density or microfibril angle.