贴敷新型阻尼材料对油底壳减振降噪规律效果的研究

Study on the Effect of Applying New Damping Material to Vibration and Noise Reduction of Oil Sumps

热气机作为特种船舶使用的发动机,对其振动噪声性能具有严格的要求。在对某型热气机油底壳进行模 态、振动特性的测量和分析的基础上,针对贴敷自由阻尼层结构,进行整体复合层减振效果的分析和试验研究。得出 宽频域载荷激励下,新型阻尼材料对油底壳振动响应衰减的规律。通过对比不同阻尼层厚度和不同阻尼材料的弹性 模量,发现:阻尼层厚度越大,复合结构的损耗因子越大;阻尼材料弹性模量越大,复合结构的损耗因子也越大,阻尼特 性越好。又对新型阻尼材料在复合层中的阻尼特性开展研究,分析阻尼材料对油底壳减振的规律,提出利用其大弹性 模量来进一步提高复合结构的损耗因子,减小阻尼层厚度也能达到减振效果的结构设计思路,成果已应用于某型大功 率热气机的整机低噪声设计,具有一定的工程实用意义。

As the engine used in special ships,the Stirling engine are strictly required on its vibration and noise performance.Based on the measurement and analysis of the modals and vibration characteristics of the oil pan of a certain type of Stirling engine,the vibration reduction effect of the integral composite layer is analyzed and tested for the structure with free damping layers attached.The law of attenuation of vibration response of the new damping material to the oil sump under broadband excitation is obtained.By comparing the effects of different thickness of the damping layer and the elastic modulus of different damping materials,it is found that the loss factor of the composite structure increases with the increasing of the thickness of the damping layer and the elastic modulus of the damping material.Then,the damping characteristics of the new damping materials in the composite layer are studied.The influence law of the damping materials on the vibration attenuation of the oil pan is analyzed.The structural design ideas of using the large elastic modulus of the damping material and reducing the thickness of the damping layer to further improve the loss factor of the composite structure and achieve the damping effect are put forward.The results have been applied to the low noise design of a certain type of high-power Stirling engine,and have a practical significance in engineering.