There are several techniques to characterize the elastic modulus of wood and those currently using the natural frequencies of vibration stand out as they are non-destructive techniques, producing results that can be repeated and compared over time. This study reports on the effectiveness of the testing methods based on the natural frequencies of vibration versus static bending to obtain the elastic properties of reforested structural wood components usually employed in civil construction. The following components were evaluated: 24 beams of Eucalyptus sp. with nominal dimensions (40 x 60 x 2.000 mm) and 14 beams of Pinus oocarpa with nominal dimensions (45 x 90 x 2.300 mm) both without treatment; 30 boards with nominal dimensions (40 x 240 x 2.010 mm) and 30 boards with nominal dimensions (40 x 240 x 3.050 mm), both of Pinus oocarpa and with chromate copper arsenate (CCA) preservative treatment. The results obtained in thiswork show good correlation when compared to the results obtained by the static bending mechanical method, especially when applying the natural frequency of longitudinal vibration. The use of longitudinal frequency was reliable and practical, therefore recommended for determining the modulus of elasticity of wood structural elements. It was also found that no specific support is needed for the specimens using the longitudinal frequency, as well as no previous calibrations, reducing the execution time and enabling to test many samples.
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机译：有几种技术可以表征木材的弹性模量，而目前使用振动固有频率的那些技术却是非破坏性技术，因此脱颖而出，其结果可以随时间重复和比较。这项研究报告了基于振动与静态弯曲的固有频率的测试方法的有效性，以获取通常用于民用建筑的重新造林的结构木构件的弹性性能。评价了以下成分：24束桉树。标称尺寸为（40 x 60 x 2.000 mm）和14根松木束标称尺寸为（45 x 90 x 2.300 mm）都未经处理； 30块标称尺寸（40 x 240 x 2.010毫米）的木板和30块标称尺寸（40 x 240 x 3.050毫米）的木板，均为松果皮和砷酸铬（CCA）防腐处理。与通过静态弯曲机械方法获得的结果相比，在这项工作中获得的结果显示出良好的相关性，尤其是在应用纵向振动的固有频率时。纵向频率的使用是可靠且实用的，因此建议用于确定木质结构元件的弹性模量。还发现使用纵向频率的样品不需要特殊的支撑，也不需要先前的校准，从而减少了执行时间并可以测试许多样品。
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