云杉木材钢琴共振板振动特性的研究

钢琴共振板是钢琴最重要的部件之一，对钢琴声学品质有决定性的影响。研究共振板振动特性对提高钢琴产品质量具有重要的意义。该文在分析钢琴共振板基本振动理论的基础上，得出了自由振动的频率方程。并以俄罗斯远东红皮云杉、东北长白鱼鳞云杉、西藏林芝云杉、美国西加云杉4个树种共8块共振板(每个树种2块)为研究对象，采用基于打击音的快速傅立叶变换频谱分析方法，测定了计算共振板弹性模量等参数所必须的(2,0)、(0,2)、(1,1)、(2,2)阶振动频率。应用自由振动频率方程计算了共振板的弯曲刚度与扭转刚度，进而计算共振板不同方向的动态弹性模量、纵波传播速度。分析共振板振动特性与钢琴声学品质主观评价、客观评价指标之间的关系得出，共振板y方向振动特性与钢琴声学品质之间的关系比x方向显著。随着共振板的弹性模量与纵波传播速度的增大，钢琴声学品质提高，尤其是共振板y方向的弹性模量与纵波传播速度值，对钢琴声学品质影响显著。这也说明了共振板y方向的振动特性参数检测对于钢琴声学品质评价的重要性。 

Vibration properties of piano resonance board from spruce wood

Resonance board is one of the most important components of piano,which predominate the acoustical quality.The frequency equation of free vibration for resonance boards on the basis of vibration theory was established.The resonant frequencies of(2,0),(0,2),(1,1) and(2,2) of all the 8 pieces of resonance boards made from the species of P.glehnii,P.jezoensis,P.spinlosa and P.sitchensis were determined using the spectrum analysis method based on fast Fourier transform.The flexural and torsional rigidities were ...