Detection and assessment of wood decay in glulam beams using a modified impulse-echo approach

Adam Senalik; Megan E. McGovern; Frank C. Beall; Henrique Reis

doi:10.1117/12.814866

30 March 2009 Detection and assessment of wood decay in glulam beams using a modified impulse-echo approach

Adam Senalik, Megan E. McGovern, Frank C. Beall, Henrique Reis

Proceedings Volume 7292, Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems 2009; 72920Y (2009) https://doi.org/10.1117/12.814866
Event: SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring, 2009, San Diego, California, United States

Abstract

A glulam beam retired from the field and without visible indications of wood decay was used. Towards detection and assessing wood decay, X-ray computer tomography and ultrasonic measurements were carried out. It was observed that decrease in mass density with increasing levels of wood decay affects x-rays attenuation and allows radioscopy to detect and assess wood decay. To detect and assess decay when only one lateral side of the beam is available, a modified impulse-echo was developed. The modified impulse-echo approach is based on observing the dynamic response of the glulam beams to the drop of a steel sphere onto a steel plate coupled to the glulam beam lamina. It was observed that monitoring certain frequency bands allows detection and assessment of wood decay. The selection of these frequency bands requires knowledge of the nominal beam transverse dimensions. Because of the high ultrasonic material attenuation values of decayed wood as compared with those of sound wood, the area under the power spectral density in these frequency bands is smaller in regions of decayed wood. Results show that results from both X-ray computer tomography and impulse-echo measurements are consistent with each other and can be used to detect and assess wood decay in structural lumber.

Citation Download Citation

Adam Senalik, Megan E. McGovern, Frank C. Beall, and Henrique Reis "Detection and assessment of wood decay in glulam beams using a modified impulse-echo approach", Proc. SPIE 7292, Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems 2009, 72920Y (30 March 2009); https://doi.org/10.1117/12.814866

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available