The NIR result also shows that the melt pool size is correlated with the energy density; the higher the energy density, the longer the melt pool, though the melt pool width remains similar. The region from which the trees were removed, but also the number of trees from which the sample material has been obtained, must be taken into account since they could have an impact on the material properties. Mechanisms for the observed results are discussed. 1995; Pan et al. Optical Engineering. Lond Edinb Dublin Philos Mag J Sci 41:206–210. Because of the low stiffness in the transverse direction of wood, only low clamping forces act and therefore no slippage was guaranteed. Poisson's ratio for thin Au films using a visual image tracing system." Holzforschung 71:405–414. Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. The model by Hörig (1935) is the basis for the orthotropic description of wood that is used nowadays. By subtracting the new speckle pattern from the reference pattern, an illustration with typical fringe pattern is obtained (Jones and Wykes 1989). The laser and video extensometry measurements were carried out on a universal testing machine Zwick/Roell Z020 (Ulm, Germany), equipped with an optical extensometer system including both gauging techniques. Terms of Use: http://spiedl.org/terms, parameter of material, which is a fundamental parameter ch, Nowadays, there are a lot of researches focused on evalua, characterizing thin film materials [8-16], where Poisson’s ratio, general, they can be classified into static, dy.

\kern-0pt} {G_{\text{LR}} }}} \\ \end{array} } \right) \cdot \left( {\begin{array}{*{20}c} {\sigma_{\text{L}} } \\ {\sigma_{\text{R}} } \\ {\sigma_{\text{T}} } \\ {\tau_{\text{RT}} } \\ {\tau_{\text{TL}} } \\ {\tau_{\text{LR}} } \\ \end{array} } \right)$$,$$- \frac{{\nu_{\text{RL}} }}{{E_{\text{R}} }} = - \frac{{\nu_{\text{LR}} }}{{E_{\text{L}} }}$$,$$- \frac{{\nu_{\text{TL}} }}{{E_{\text{T}} }} = - \frac{{\nu_{\text{LT}} }}{{E_{\text{L}} }}$$,$$- \frac{{\nu_{\text{TR}} }}{{E_{\text{T}} }} = - \frac{{\nu_{\text{RT}} }}{{E_{\text{R}} }}.$$,$$\varepsilon_{\text{l}} = \frac{\Delta F}{{A*{\text{MOE}}}},, https://doi.org/10.1016/S0143-8166(02)00085-4, https://doi.org/10.1007/s00226-016-0851-z, https://doi.org/10.1080/17480272.2015.1030773, https://doi.org/10.1080/14786442108636212, https://doi.org/10.1017/S2398187300139465, https://doi.org/10.1080/14786442208633943, https://doi.org/10.1007/s11340-008-9162-0, https://www.dantecdynamics.com/3d-espi-system-q-300, https://doi.org/10.1016/0263-2241(95)00019-4, https://doi.org/10.1111/j.1475-1305.2009.00687.x, https://doi.org/10.1007/s00226-010-0362-2, https://doi.org/10.1007/s00226-005-0051-8, https://doi.org/10.1007/s00226-011-0449-4, https://doi.org/10.1007/s00226-008-0192-7, https://doi.org/10.1007/s00226-006-0090-9, https://doi.org/10.1007/s00226-017-0980-z, https://doi.org/10.1007/s11340-011-9560-6, http://www.messphysik.com/fileadmin/messphysikdaten/Download/Laser_speckle_extensometer_en.pdf#page=16&zoom=auto,-205,558, https://doi.org/10.1007/s00226-015-0755-3, https://doi.org/10.1007/s00107-007-0188-2, https://doi.org/10.1007/s11340-016-0180-z, https://doi.org/10.1088/0957-0233/20/6/062001, https://doi.org/10.1016/j.ijsolstr.2010.01.014, https://doi.org/10.1016/j.engstruct.2016.01.052, https://doi.org/10.1007/s00226-010-0394-7, https://www.asminternational.org/documents/10192/1908540/amp16204p033.pdf/612298f5-c258-4490-ab3e-3ebc3f6e4daf, https://doi.org/10.1111/j.1747-1567.2008.00370.x, https://doi.org/10.1007/s00226-012-0507-6, http://www.zwickusa.com/en/products/extensometers/non-contact-extensometers/laserxtensr.html, http://www.zwickusa.com/en/products/extensometers/non-contact-extensometers/videoxtensr.html, https://www.zwick.com/extensometers/makroxtens, http://creativecommons.org/licenses/by/4.0/, https://doi.org/10.1007/s00226-018-1045-7. Therefore, the extensometer system contains a gauging sensor, a digital camera and a laser light source. A technique has been developed to measure the longitudinal and lateral displacements under uniaxial loading of the films on a microscale. Wood Sci Technol 40:351–357. 2005; Konnerth et al.

Accessed 30 Aug 2017, Zwick/Roell (2017c) Mechanical-extensometer: makroXtens (Zwick/Roell). The schematic diagram of AIC is shown in figure 3. The Poisson’s ratio. In summary, the study shows that optical gauging techniques are suitable for determining the Poisson’s ratios of (spruce) wood. An original and practical method is demonstrated for determining Poisson’s ratio of thin films by detecting thermal expansion in two directions perpendicular to each other.

deformation distributions as a straight line following the theoretical diffraction model. https://doi.org/10.1007/BF02325092, Crespo J, Aira JR, Vázquez C, Guaita M (2017) Comparative analysis of the elastic constants measured via conventional, ultrasound, and 3-D digital image correlation methods in Eucalyptus globulus labill. Ultramicroscopy. 2011; Bader et al. Reliable FEM is based on a sound data basis of material properties, such as elastic constants, including the Poisson’s ratio (ν). The stiffness or compliance matrix is symmetric due to Betti’s reciprocity theorem [the deflection d (in direction A) due to a unit force p (in direction B) is equal to the deflection d (in direction B) due to a unit force p (in direction A)]. .

Accessed 3 Oct 2017. It should be calculated from the initial portion of the load (or stress) versus strain curve.