Development of Advanced Concepts for Noise Reduction in Tracked Vehicles.

摘要

This investigation develops an understanding of the noise sources, the acoustical and vibratory paths through which energy enters the hull structure, and the mechanism by which noise arrives at personnel locations. A theoretical and experimental analysis of primary noise source of the vehicle, i.e. the track and suspension system, consisted of three phases: (1) The design of a computer program to simulate the track and suspension; (2) The isolation of the noise produced by the sprocket, idler and roadwheels to determine the contribution of each of these sources; and (3) The measurement of vibration levels at the suspension system, and force-to-noise transfer functions for predicting interior noise levels. This study indicates that at speeds above 10 mph the engine is not a major contributor to noise, and the roadwheels produce significantly less noise than the sprocket and idler. The study results indicate that the greatest potential for noise reduction lies in providing a softer compliance between the idler and the track. This should be followed by lowering the stiffness of the sprocket and finally by controlling roadwheel noise. The idler stiffness can be lowered either at the hub or at the rim, however rim compliance poses fewer design problems. (Author)