摘要
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。
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 calculated using the established frequency equation and further the moduli of elasticity and transmitting velocity of longitudinal wave （VL） were also calculated. The subjective and objective evaluations of piano acoustical quality combined with vibration properties displayed that the vibration in y-direction correlated more with acoustical quality than in x-direction. The acoustical quality was improved with the increase in MOE and VL, especially in y-direction. The results show that the parameter measurement of vibration properties in y- direction is more important to the acoustical quality of piano.
出处
《北京林业大学学报》
EI
CAS
CSCD
北大核心
2008年第5期129-133,共5页
Journal of Beijing Forestry University
基金
国家自然科学基金项目(30070607)
东北林业大学青年科研基金项目(07014)
关键词
云杉木材
钢琴
共振板
振动特性
声学品质
spruce wood
piano
resonance board
vibration properties
acoustical quality
