Abstract
A thermal imaging system has been used for monitoring fracture in wood under both static and fatigue torsional loading. The thermal images of softwood test-pieces containing a knot under torsional loading predicted the cracking time and crack position that agreed well with visual observation. The thermal images obtained under torsional fatigue loading indicated a temperature increase during the unloading part of a loading cycle, which meant that thermal energy was dissipated during the relaxation stage of the loading cycle. The maximum temperature reached also increased as the loading cycles increased. Results from thermal images of a softwood indicated that the earlywood exchanged more thermal energy than latewood. Optical microscopy and SEM confirmed that in earlywood the region near a growth ring is the weaker area. For all the test pieces, whether softwood or hardwood, with or without a knot, the hotspots revealed during thermal imaging appeared before the load dropped sharply and these were confirmed to be the positions for crack initiation. This shows that it is possible to predict and depict failure and its progress using thermal imaging techniques.
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References
V. BUCUR, in “Acoustics of Wood” (CRC Press, Boca Raton, New York, USA, 1995) p. 221.
Z. CHEN and B. GABBITAS, in First international conference of the Europe Society of Wood Mechanics, Lausanne, Switzerland, 19–21 April, 2001, p. 393.
R. W. RICE and C. SKAAR, Wood Sci. Techn. 24 (1990) 123.
D. WU and G. BUSSE, TAPPI 1995 Europ. Plast. Lamin. Symp. 79(8) (1995) 119.
G. DILL-LANGER and S. AICHER, in Proceedings of COST Action E8 on Wood and Wood Fiber Composites, Stuttgart, Germany, 13–15 April, 2000, p. 93.
S. G. BURNAY, T. L. WILLIAMS and C. H. JONES, in “Applications of Thermal Imaging” (Hilger Ltd., Bristol, UK, 1988) p. 1.
A. CHRYSOCHOOS, O. MAISONNEUVE, G. MARTIN, H. CAUMON and J. C. CHEZEAUX, Nucl. Engns. Design 114 (1989) 323.
G. GAUSSORGUES, in “Infrared Thermography” (Chapman & Hall, University Press, Cambridge, UK, 1994) p. xv.
V. P. VAVILOV, in “Subjective Remarks on the Terminology used in Thermal/Infrared Nondestructive Testing” in Thermosense XVIII, edited by D. D. Burleigh and J. W. M. Spicer, SPIE Proc., 2766 (1996) 276.
W. N. REYNOLDS and G. M. WELLS, Brit. J. NDT 26(1) (1984) 40.
S. K. LAU, D. P. ALMOND and J. M. MILNE, NDT Eval. Intern. 24(4) (1991) 195.
R. L. THOMAS, L. D. FAVRO, P. K. KUO, T. AHMED, X. HAN, L. WANG, X. WANG and S. M. SHEPARD, in Proceedings of 15th International Congress on Acoustics, Trondheim, Norway, June 26–30, 1995 p. 433.
G. BUSSE, D. WU and W. KARPEN, J. Appl. Phys. 71(8) (1992) 3962.
J. SEMBACH, D. WU, A. SALERNO, G. HORA and G. BUSSE, in Proceedings of Workshop on Nondestructive Testing of Panel Products, Llandudno, UK, 11 October, 1997 (J. Hague 1997) p. 41.
D. WU and G. BUSSE, in TAPPI 1995 Europ. Plast. Lamin. Symp. 79(8) (1995) 119.
Y. XU, S. OKUMURA and M. NOGUCHI, Mukuzai gakkaishi-J. 39(5) (1993) 544.
H. BERGLIND and A. DILLENZ, in 12th International Symposium on Nondestructive Testing of Wood, Sopron, Hungary, 2000 p. 413.
A. CHRYSOCHOOS and F. BELMAHJOUB, Arch. Mech. 44 (1992) 55.
A. CHRYSOCHOOS, H. LOUCHE, J. M. MURACCIOLE, M. NÉMOZ-GAILLARD, J. L. SAUREL and B. WATTRISSE, in IUTAM Symposium on Advanced Optical Methods and Applications in Solid Mechanics, Netherland, 2000, p. 313.
S. BARDET, in “Comportment thermoviscoelastique transverse du bois humide,” Ph.D Thesis (Montpellier University, France, 2001) p. 49.
K. PERSSON, Swedish Lund University/Lund Institute of Technology Report TVSM-3020 (1997)
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Chen, Z., Gabbitas, B. & Hunt, D. A thermal imaging technique for studying crack development in wood under torsional loading. J Mater Sci 40, 1929–1935 (2005). https://doi.org/10.1007/s10853-005-1213-7
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DOI: https://doi.org/10.1007/s10853-005-1213-7