Investigation of relationship between dynamic modulus of elasticity and static bending ‎properties in ‎particleboard plates

In this study the relationship between dynamic modulus of elasticity from longitudinal ývibration ýmethod with static modulus of elasticity and bending strength in two directions: the ýParallel ýmachine direction and machine direction have been investigated. For this purpose 4 ýplates of ýparticleboard with dimensions 124× 90 ×1.6 cm (length× width× thickness) were ýselected and free ýlongitudinal vibration test in PMD and MD were performed on each plates. ýAfter that the primary ýplates were cut to four plates with dimensions 62× 44 ×1.6 cm (length× ýwidth× thickness) and ýlongitudinal vibration test in PMD and MD were performed on each ýplates again. Finally each plates ýwere cut to the beams with dimensions 36× 1.6 ×1.6 cm and ýlongitudinal vibration test and and ýstatic bending test were performed on them. The results show ýthat good correlation between ýdynamic modulus of elasticity from longitudinal vibration test ýand static modulus of elasticity and ýbending strength (result of beams extracted from each ýplates) in both size of plates in two size ýý(124× 90 ×1.6 and 62× 44 ×1.6 cm) and beams ýextracted from each plates in two directions (PMD ýand MD). In addition there was good ýcorrelation between dynamic modulus of elasticity of ýlongitudinal vibration from two size plates ýý(124× 90 ×1.6 and 62× 44 ×1.6 cm). When the samples ýsmaller than primary plates, the ýdynamic modulus of elasticity values were increased, that it due to ýthe diffusion of waves in ýsamples with larger dimensions. In general, according to results of this ýresearch it can be ýconcluded that by applying the appropriate correction factors, longitudinal ývibration method an ýefficiency method for calculation of dynamic and static modulus of elasticity ýand estimate of ýthe modulus of rupture in plates in full sized.ý