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介绍了基于复刚度原理推导的自由及约束阻尼结构损耗因子理论评估计算公式,并对相关参数变化影响规律进行了理论分析,初步确定了阻尼结构形式及材料参数。为评估阻尼设计方案对实际船舶舱室的减振降噪效果,建立船舶局部舱室结构的1∶2.5缩比模型结构,采用模态锤击测量方法,对阻尼处理前、后舱室振动及噪声特性展开试验研究。试验结果表明,约束阻尼处理能明显抑制结构的模态共振。在2.5 mm厚舱室围板粘接1.7 mm厚约束阻尼层后,最大减振量为11 d B,最大降噪量达到9 d B。最后,对约束阻尼处理后的航行船舶进行实船噪声测试,噪声测试结果均满足IMO-468噪声指标要求。
This paper introduces the calculation formula of theoretical calculation of loss factor of free and constrained damped structures deduced from the principle of complex stiffness, and analyzes the influence law of the change of related parameters theoretically. The damping structure and material parameters are preliminarily determined. In order to evaluate the effect of damping design on the damping and noise reduction of the actual ship’s cabin, a 1: 2.5 reduction model structure of the ship’s partial cabin structure was established. The modal hammer measurement method was used to investigate the vibration and noise characteristics of the front and rear compartments Experimental Research. The experimental results show that constrained damping treatment can significantly suppress the mode resonance of the structure. The maximum damping of 11 d B and the maximum noise reduction of 9 dB were achieved after bonding 1.7 mm thick constrained damping layer to the 2.5 mm thick cabin wall. Finally, the real ship noise test of the ship with restrained damping is performed, and the noise test results meet the requirements of IMO-468 noise figure.