Vibrational properties of Picea woods grown in China as piano sound board

五种云杉林，（1）云杉（φ：66 cm，总年轮数：141、50 cm和141），（2）巴氏松P.balfourniana 62 cm和387）;（3）糙叶云杉（4）紫毛蕨（5）丽江松（P.likiangansis）（6）红皮云杉（P.koraiensis）由中国南方林业大学Liau教授提供。对样品的振动特性进行了测试，并进行了光学显微镜观察和x射线衍射分析。本研究的目的是寻找更好的乐器，特别是钢琴的木材质量。目前云杉木材都是从中国进口的，名为“云杉”，因此钢琴制造商对这些木材的评价很混乱，有些木材可能会被浪费。川亚木业有限公司选择的木材，有限公司被切成一定的厚板，包括髓和干燥。然后，他们被ai进口 ...更多信息 r.动态杨氏模量、刚度和正切损耗基于使用第1至第7振动模式的Rishenko方程来估计。用典型的振动试验试件制作了光镜观察试件和X射线衍射分析试件。与锡特卡云杉的评价值比较结果（Picea sitchensis）;（2）和（3）的密度比云杉低，比纵向杨氏模量均较低，比径向杨氏模量（1）、（3）和（6）较小，径向切向损失比锡特卡云杉大30 ~ 50%。Er/Gr是一个显著的音板指标，且值越大越好，在不同树种间分布范围越广，甚至在同一树种间也存在差异，说明少数树种具有较好的音板性能，但也有一些树种表现出较好的音板性能。如果我们能很容易地识别出那些优质木材，那么一架上级钢琴就会用中国云杉木材制造出来。少

Five Picea woods, (1)Picea complanata (phi : 66cm and total annual ring number : 141, 50cm and 141), (2)P.balfourniana (62cm and 350, 62cm and 387), (3)P asperata(54cm, and 152), (4)P.purpurea (80cm and 291, 54cm and 304), and(5)P.likiangansis (54cm and 216, 62cm and 293) were collected in Sichuan province, China and another one, (6)P.koraiensis was given by Professor Liau, South-cast Forestry University, China. Vibrational properties were examined and then light microscopic observation and x-ray diffraction analysis were carried. The aim of this research is to find better quality of wood for musical instruments, especially for piano. At present all the Picea woods have been imported from China named 'kumosugi', as the result there is a big confusion in evaluation of those woods by piano makers, and some woods might be wasted.Lumbers that were selected at Chuanya Wood Industry Co., Ltd. were cut into a certain thick boards that include the pith and dried. Then, they were imported by ai … More r.Dynamic Young's modulus, rigidity and tangent loss were estimated based on Timoshenko's equation using 1st to 7th vibration modes. Test specimens for light microscopic observation and x-ray diffraction analysis were manufactured from some typical specimens for vibration test.Results of comparison of the evaluated values with those of sitka spruce (Picea sitchensis) were ; the density of(2) and (3)is lower than sitka spruce, all the specific longitudinal Young's modulus was lower, specific radial Young's modulus of(1), (3) and (6)was smaller, tangenf loss in the radial direction was larger 30 to 50% than that of sitka spruce. Er/Gr a significant index for soundboard and larger value is preferable, distributed in a wide range among the woods, and differed even between the same species.It is concluded that there were very few species better for soundboard, but some was seemed to be excellent. If we can easily identify those of good quality wood, then a superior piano will be manufactured with Chinese spruce wood. Less