Title :
2D-5 Combining X-Rays and Ultrasound to Determine Micro-Elasticity
Author :
Salmi, A.H. ; Meriläinen, A. ; Hæggström, E. ; Torkkeli, M. ; Serimaa, R.
Author_Institution :
Univ. of Helsinki, Helsinki
Abstract :
We continue our quest to determine localized micro- elasticity by combining a standing ultrasonic wave pattern and SAXS X-ray diffraction (CuKalpha 1.54 Aring) to map the local elastic modulus. This was done in 20times20times1.5 mm3 dry Scots pine (Pinus Sylvestris L) soft wood and high-density polyethene (HDPE), acting as homogenized wood phantom samples. An Atmel Atmega 8515 (8 bit, 16 MHz) microprocessor launches and upholds a resonant lambda/2 wave pattern in the radial wood direction using a 100 Hz feedback loop. By varying the transmitted ultrasonic power, it is possible to alter the local stress within the volume probed by the 1 mm2 X-ray beam. The local strain in unit crystals is determined from changes in the width and position of the X-ray diffraction peaks. The results indicate that the method is applicable for localized quantitative elasticity mapping.
Keywords :
X-ray diffraction; elastic moduli; elasticity; internal stresses; micromechanics; ultrasonic imaging; wood; Atmel Atmega microprocessor; Pinus Sylvestris L; SAXS X-ray diffraction; Scots pine; X-rays; high-density polyethene; homogenized wood phantom samples; local elastic modulus; local stress; localized microelasticity; microelasticity determination; quantitative elasticity mapping; standing ultrasonic wave pattern; ultrasonic power; ultrasound; Capacitive sensors; Crystals; Elasticity; Feedback loop; Imaging phantoms; Microprocessors; Resonance; Stress; Ultrasonic imaging; X-ray diffraction;
Conference_Titel :
Ultrasonics Symposium, 2007. IEEE
Conference_Location :
New York, NY
Print_ISBN :
978-1-4244-1384-3
Electronic_ISBN :
1051-0117
DOI :
10.1109/ULTSYM.2007.27
