@Article{Zhang_etal2011,
author="Zhang, T.
and Bai, S.-L.
and Bardet, S.
and Almeras, T.
and Thibaut, B.
and Beauchene, J.",
title="Radial variations of vibrational properties of three tropical woods",
journal="Journal of Wood Science",
year="2011",
volume="57",
number="5",
pages="377--386",
optkeywords="Damping coefficient",
optkeywords="Dynamic modulus",
optkeywords="Extractives",
optkeywords="Microfibril angle",
optkeywords="Tropical woods",
abstract="The radial trends of vibrational properties, represented by the specific dynamic modulus (E{\textasciiacutex}/$\rho$) and damping coefficient (tan $\delta$), were investigated for three tropical rainforest hardwood species (Simarouba amara, Carapa procera, and Symphonia globulifera) using free-free flexural vibration tests. The microfibril angle (MFA) was estimated using X-ray diffraction. Consistent patterns of radial variations were observed for all studied properties. E{\textasciiacutex}/$\rho$ was found to decrease from pith to bark, which was strongly related to the increasing pith-bark trend of MFA. The variation of tan $\delta$ along the radius could be partly explained by MFA and partly by the gradient of extractives due to heartwood formation. The coupling effect of MFA and extractives could be separated through analysis of the log(tan $\delta$) versus log(E{\textasciiacutex}/$\rho$) diagram. For the species studied, the extractive content putatively associated with heartwood formation generally tends to decrease the wood damping coefficient. However, this weakening effect of extractives was not observed for the inner part of the heartwood, suggesting that the mechanical action of extractives was reduced during their chemical ageing. {\textcopyright} 2011 The Japan Wood Research Society.",
optnote="Export Date: 26 October 2011; Source: Scopus; Coden: Jwscf; doi: 10.1007/s10086-011-1189-7; Language of Original Document: English; Correspondence Address: Bai, S.-L.; Department of Advanced Materials and Nanotechnology, College of Engineering, Peking University, Beijing 100871, China; email: slbai@pku.edu.cn",
optnote="exported from refbase (http://php.ecofog.gf/refbase/show.php?record=363), last updated on Tue, 23 Oct 2012 07:21:38 -0300",
issn="14350211 (Issn)",
opturl="http://www.scopus.com/inward/record.url?eid=2-s2.0-80054013025&partnerID=40&md5=aea06ae46d8dacccba984a9e8b73ef95"
}