【摘要】 本文运用频谱分析和相干函数理论,建立了识别拖拉机驾驶室内主噪声源的多输入单输出力学模型,利用自编程序计算了常相干函数、重相干函数和偏相干函数,并且通过实验分析,验证了力学模型的正确性,确定了驾驶室内主噪声源和主噪声传递通道。 实验分析表明,驾驶室内主噪声频率是发动机的燃烧基频,主噪声源是由驾驶室板件振动辐射出来的固体声,驾驶室的主激振源是发动机的振动。根据分析结果,对驾驶室采取了降噪措施,使驾驶员的耳旁噪声由96dB(A)降低到90.5dB(A)。更多还原

【Abstract】 Accrding to the frequency spectrum analysis and the theory of coherence fun ction, set up the mechanical model for the multiple input/single output system, by which the main noise source in the tractor cab can be distinguished. In addition, the ordinary coherence function , multiple coherence function and partical coherence function have been calculated with the help of the Computer Programms which is worked out by ourselves. And through the experiment and analysis the correctness of the mechanical model has been verified, the main noise source and the main noise transmitting line in the tractor cab have been found.The three conclusions are obtained based on the test: ( 1 ) The main noise frequency in the tractor cab is basic burning frequency of engine. ( 2 ) The main noise source is the solid noise from vibration of the tractor cab and( 3 ) The vibration source of the tractor cab is the engine vibration.Based on the experiment and analysis, the measures to reduce the noise in the tractor cab has been taken and the driver’s head noise has been reduced from 96 dB (A) to 90.5dB(A).更多还原