A simple anisotropy correction procedure for acoustic wood tomography

Maurer, Hansruedi; Schubert, Sandy; Bächle, Fritz; Clauß, Sebastian; Gsell, Daniel; Dual, Jürg; Niemz, Peter

doi:10.1515/hf.2006.094

Cited by 40 publications

(34 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This equation can be used to calculate the velocity of shear and compressional dilatational (bulk) waves in different propagation directions relative to the orthotropic axes. [68][69][70][71][72][73][74][75] Other models, including the Hankinsen's model, have been proposed for the speed of sound in wood as a function of grain angle in the radial/tangential [76][77][78] and longitudinal 79 directions. The Kelvin-Christoffel equation can be used to calculate the theoretical speed of an acoustic dilatational wave (in an infinite unbounded medium).…”

Section: Orthotropic Mechanical Properties Of Woodmentioning

confidence: 99%

Measurement of stiffness of standing trees and felled logs using acoustics: A review

Legg

Bradley

2016

The Journal of the Acoustical Society of America

View full text Add to dashboard Cite

This paper provides a review on the use of acoustics to measure stiffness of standing trees, stems, and logs. An outline is given of the properties of wood and how these are related to stiffness and acoustic velocity throughout the tree. Factors are described that influence the speed of sound in wood, including the different types of acoustic waves which propagate in tree stems and lumber. Acoustic tools and techniques that have been used to measure the stiffness of wood are reviewed. The reasons for a systematic difference between direct and acoustic measurements of stiffness for standing trees, and methods for correction, are discussed. Other techniques, which have been used in addition to acoustics to try to improve stiffness measurements, are also briefly described. Also reviewed are studies which have used acoustic tools to investigate factors that influence the stiffness of trees. These factors include different silvicultural practices, geographic and environmental conditions, and genetics.

show abstract

Section: Orthotropic Mechanical Properties Of Woodmentioning

confidence: 99%

Measurement of stiffness of standing trees and felled logs using acoustics: A review

Legg

Bradley

2016

The Journal of the Acoustical Society of America

View full text Add to dashboard Cite

show abstract

“…They found a significant difference in wave velocity between the waves propagating in whole volume and the waves guided on bars. Maurer et al (2006) developed a simple correction scheme that removes first-order anisotropy effects. The corrected travel-time data can be inverted with isotropic inversion codes that are commercially available.…”

Section: Introductionmentioning

confidence: 99%

Velocity Error Correction Based Tomographic Imaging for Stress Wave Nondestructive Evaluation of Wood

Huan¹,

Zhi²,

Li³

et al. 2018

BioResources

View full text Add to dashboard Cite

Stress wave testing has been applied in the nondestructive evaluation of wood for many years. However, the anisotropy property of wood and the limited number of sensors prevent an accurate stress wave velocity measurement and the high resolution of tomographic inversion. This paper proposes a tomographic imaging algorithm (IABLE) with a velocity error correction mechanism. The proposed algorithm computed the wave velocity distribution of the grid cells of wood cross-sections by the least square QR decomposition (LSQR) iterative inversion, and then optimized the tomography with a velocity error correction mechanism (ECM). To evaluate the performance of the proposed algorithm, several healthy and defective logs and live trees were selected as the experimental samples, and the nondestructive testing procedures were finished. With the stress wave velocity data sets measured via a PiCUS 3 stress wave testing instrument, the IABLE algorithm was implemented, and the tomographic images of the log samples and live trees were generated. The experimental results demonstrated the effectiveness of the proposed imaging algorithm for the nondestructive evaluation of wood.

show abstract

“…The idea of X-ray projection microscopy originated in the 1950s (Cosslett & Nixon, 1951;Nixon, 1955), but such systems were developed and made usable only in the last decade (Mayo et al, 2002(Mayo et al, , 2003. Tomography has been performed in various media, for example, acoustic waves (Maurer et al, 2006) or neutrons (Dierick et al, 2005) and X-rays. Some other examples of current techniques established for X-ray microcomputed tomography are: synchrotron X-ray tomography (with less than one µm 3 resolution) (Bonse & Bush, 1996;Laiarinandrasana et al, 2010) and laboratory desktop microtomography, which can reach down to 5 µm spatial resolution (Weiss et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

Revealing the 3D internal structure of natural polymer microcomposites using X-ray ultra microtomography

Pakzad

Parikh

Heiden

et al. 2011

Journal of Microscopy

View full text Add to dashboard Cite

SummaryProperties of composite materials are directly affected by the spatial arrangement of reinforcement and matrix. In this research, partially hydrolysed cellulose microcrystals were used to fabricate polycaprolactone microcomposites. The spatial distribution of cellulose microcrystals was characterized by a newly developed technique of X-ray ultra microscopy and microtomography. The phase and absorption contrast imaging of X-ray ultra microscopy revealed twodimensional and three-dimensional information on CMC distribution in polymer matrices. The highest contrast and flux (signal-to-noise ratio) were obtained using vanadium foil targets with the accelerating voltage of 30 keV and beam current of >200 nA. The spatial distribution of cellulose microcrystals was correlated to the mechanical properties of the microcomposites. It was observed that heterogeneous distribution and clustering of cellulose microcrystals resulted in degradation of tensile strength and elastic modulus of composites. The utilization of X-ray ultra microscopy can open up new opportunities for composite researchers to explore the internal structure of microcomposites. X-ray ultra microscopy sample preparation is relatively simple in comparison to transmission electron microscopy and the spatial information is gathered at much larger scale.

show abstract

A simple anisotropy correction procedure for acoustic wood tomography

Cited by 40 publications

References 13 publications

Measurement of stiffness of standing trees and felled logs using acoustics: A review

Measurement of stiffness of standing trees and felled logs using acoustics: A review

Velocity Error Correction Based Tomographic Imaging for Stress Wave Nondestructive Evaluation of Wood

Revealing the 3D internal structure of natural polymer microcomposites using X-ray ultra microtomography

Contact Info

Product

Resources

About