二维周期阻尼薄板结构的隔声特性

Sound Transmission Loss of Thin Plate with Two-dimensional Periodically Bulk-damping

薄板结构中,传统大块敷设阻尼虽然能提高隔声量,但不利于轻量化设计,因此提出二维周期阻尼敷设方式,借助有限元法及VA one声学仿真软件,分析二维周期块状阻尼分布、形状等参数对薄板隔声特性的影响。结果表明,随着阻尼数目的增加,在16~125Hz和250~1 000 Hz频段内,6块阻尼敷设方式隔声量最小;全频段范围内,x、y方向晶格常数均为100mm时,隔声量最小。因此,在特定频段内,合理调整周期阻尼结构的晶格常数及阻尼数目能使隔声量达到最大;二维周期阻尼形状对隔声量有较大的影响,对于圆、正三角形及矩形三种特定的阻尼形状而言,圆形阻尼形状隔声效果最优。

The conventional big block damping can increase the sound transmission loss of thin plate,but goes against the light weight design.Thus a two-dimensional periodically bulk-damping design is proposed in this paper.The influence of the bulk-damping parameters including distribution and shape on sound transmission loss are researched by FEM and VA one software.The results showed that the sound transmission loss was minimum with 6damping blocks laid,at the frequency range of 16 to 125Hz and 250 to 1 000 Hz with the increase of the number of damping blocks;while in the whole frequency band,the sound transmission loss reached the minimum when the lattice constant reached to 100 mm both in the x and y direction.So changing the lattice constant of the periodical damping structure and the damping number properly can maximize sound transmission loss in specific frequency bands.Different shapes of bulk-damping greatly influence the sound transmission loss.As for the damping shape of circle,equilateral triangle and rectangle,the circular bulk-damping possesses the best sound transmission loss.