Application of nondestructive ultrasound techniques, transverse vibration and stress-wave for timber evaluation

Abstract

The application of nondestructive techniques can assist in timber evaluation, without the need to extract specimens. Two of the main mechanic evaluation techniques are the nondestructive techniques of ultrasound and transversal vibration . The evolution in the use of nondestructive techniques has led to the development of new technologies, particularly the stress-wave technique, which allows the obtention of tomographic images of timber. The purpose of this study was to verify the accuracy of the ultrasonic and transverse vibration techniques in comparison with the values obtained from static tests and tomographic images obtained through the use of stress waves for Eucalyptus citriodora. The values of the coefficient of determination for the ultrasonic technique (R ² = 0.76) and for the transverse vibration technique (R ² = 0.80) were significant, demonstrating that the ultrasonic and transverse vibration techniques are important tools for the nondestructive inference of the modulus of elasticity of timber. The results also show that the tomographic images obtained through the use of the stress-wave technique allow the percentage of deteriorated area of timber to be estimated with adequate reliability.

Keywords:
Nondestructive testing; Ultrasonic; Transverse vibration; Stress wave