CAJ | 학술논문

基于多体系统动力学理论、有限元和边界元方法，使用多种仿真软件建立车身结构有限元模型、整车刚柔耦合系统模型和车厢声学边界元模型，对路面不平度和发动机振动两种激励进行模拟，计算了这两种激励条件下20～150 Hz频率范围内车厢内各场点的A计权声压级。以降低多个场点声压级峰值为目标，综合考虑车厢壁板对各场点声压级峰值的声学贡献度大小和正负性质，对不同壁板组合进行阻尼减振降噪处理，最终确定最佳阻尼降噪方案。结果表明：场点声压级峰值的大小和频率分布与激振力能量的频率分布有关，粘贴阻尼材料在降低噪声的同时，也会改变声压级的频率分布。降噪措施能普遍降低车厢内乘员耳旁的声压级。
기우다체계통동역학이론、유한원화변계원방법，사용다충방진연건건립차신결구유한원모형、정차강유우합계통모형화차상성학변계원모형，대로면불평도화발동궤진동량충격려진행모의，계산료저량충격려조건하20～150 Hz빈솔범위내차상내각장점적A계권성압급。이강저다개장점성압급봉치위목표，종합고필차상벽판대각장점성압급봉치적성학공헌도대소화정부성질，대불동벽판조합진행조니감진강조처리，최종학정최가조니강조방안。결과표명：장점성압급봉치적대소화빈솔분포여격진력능량적빈솔분포유관，점첩조니재료재강저조성적동시，야회개변성압급적빈솔분포。강조조시능보편강저차상내승원이방적성압급。
Based on the theory of multi-body system dynamics, the finite element model of vehicle’s body, the rigid-flexible coupled model of the vehicle and the acoustic boundary element model of the vehicle of an ambulance carriage were established by applying a variety of simulation codes. Road roughness and engine vibration were simulated and the weighted SPL of field points in the carriage under these excitations were computed in the frequency range of 20~150 Hz. Considering the magnitudes and the positive/negative nature of wall panels’acoustic contribution, damping treatments were taken on different combinations of panels to reduce the SPL peak values at several field points. Finally, the optimal damping treatment was confirmed. The results show that the magnitudes and frequency distribution of the SPL peaks of the field points depends on the frequency distribution of the exciting force’s energy. The adhesive damping materials can reduce the noise as well as change the frequency distribution of the SPL. The noise reduction measures can also reduce the SPL around the crew of the ambulance.