Flexural Strength in a Whole MDF Panel; a Nondestructive Approach

A vibrational base nondestructive method is proposed to estimate the modulus of rupture (MOR) in medium density fiberboard (MDF) whole plate. A premium grade MDF panel was tested in longitudinal and flexural vibration approaches in panel longitudinal axis and its perpendicular direction. Then, the panel was cut into smaller and smaller plates and prismatic beams while the vibrational properties were collected in each step. Finally, the static bending method was used to evaluate the static MOE and MOR in final prismatic MDF beams. The dynamic and static MOEs were compared together and used along with the logarithmic decrement to correlate with static MOR of the beams. A multi-regression model of lumber MOR prediction was fitted also to MDF plate, considering a correction coefficient in terms of vibration plane (longitudinal or flexural). The modified multi-regression model for the MDF panel was successful to estimate MOR, comparable to those of obtained in static bending standard methodology.