CAJ | 학술논문

首次研究了颗粒阻尼对封闭空腔内场点声压的影响。通过推导声压的计算公式,揭示了声压与模态振型之间的联系。通过某轿车车身简化缩小模型的模态试验,研究了其模态振型的构成。并通过在此封闭空腔的低阶振型内相对位移较大的面上布置颗粒阻尼,降低了此封闭空腔内参考点的声压。结果显示,相比无颗粒阻尼,当颗粒阻尼安装于此封闭空腔的第一阶模态振型内相对位移较大的面上时,封闭空腔内参考点的A计权声压级降低程度最大,由104．56 dB降至101．03 dB,下降了约3．4%。
수차연구료과립조니대봉폐공강내장점성압적영향。통과추도성압적계산공식,게시료성압여모태진형지간적련계。통과모교차차신간화축소모형적모태시험,연구료기모태진형적구성。병통과재차봉폐공강적저계진형내상대위이교대적면상포치과립조니,강저료차봉폐공강내삼고점적성압。결과현시,상비무과립조니,당과립조니안장우차봉폐공강적제일계모태진형내상대위이교대적면상시,봉폐공강내삼고점적A계권성압급강저정도최대,유104．56 dB강지101．03 dB,하강료약3．4%。
Acoustic pressure in the enclosed cavity affected by particle damping was firstly studied. By inducing the formula of acoustic pressure, the contact between modal shapes and acoustic pressure was studied. The modal shapes of the enclosure cavity which is simplified and reduced proportionally from a vehicle body were analyzed by modal test. By equipping the board of which relative displacement is the maximum in lower-order modal shapes of the enclosure cavity with particle damping, the vibration of the lower-order modal is reduced. Then the acoustic pressure of the enclosure cavity is reduced. The results show that compared with none particle damping, the de-crease of the A-weighted RMS acoustic pressure at the reference point in the enclosure cavity is the most, from 104. 56 dB to 101. 03 dB, decreased by 3. 4% when particle damping was equipped on the board of which relative displacement is the maximum in first modal shape of the enclosure cavity.