بررسي امكان اندازه گيري مدول الاستيسيته و فاكتور ميرايي ارتعاش در چوب سروسيمين توسط آزمون غيرمخرب ارتعاش آزاد و مقايسه آن با روش هاي استاتيك و ارتعاش اجباري

Investigation on the Possibility of Modulus Elasticity and Damping Factor Measurements, in timbers from Arizona Cypress Using Free Vibration NDT in Comparison with Static Bending and Forced Vibration NDT

A method was previously developed in CIRAD Montpellier, France, to measure the specific Youngs modulus in fibre direction by free-free vibration of a wooden bar. This method, based on Timoshenko beam theory, accounts for the shear deformation and provides an estimate of shear moduli. It has been improved and implemented in MATLAB software, in view of the future association with a measurement method of the damping factor, modulus of elasticity and shear moduli at the same time. Results obtained in Iran on Cupressus arizonica wood specimens using the new system, named NDT-lab, were compared with data obtained on the same material in Montpellier, France, using CIRAD method and data obtained on the same material in Static bending method. A good agreement between three methods was obtained