Experimental Idler Design and Development of Hull Concepts for Noise Reduction in Tracked Vehicles

摘要

The first phase of this study rank ordered the major noise sources of the M113A1 Armored Personnel Carrier and developed a preliminary mathematical model of the track and suspension system. Vibration-to-noise transfer functions were experimentally derived for inclusion in the model. The present study was designed to capitalize upon those achievements by designing a high compliance idler, and by refining the computer model so that additional precision could be gained and a greater number of parameters varied. A power flow analysis of the hull was conducted along with structural modifications and damping treatment of a number of promising areas. Computer runs were made to verify the model and to study the effect upon interior noise of several theoretical changes to the suspension system. Test of the experimental compliant idler indicate that heat buildup and durability will not present problems. A cursory examination of its noise level indicated that this idler may provide significant noise reduction. analysis of the acoustic and vibratory power flow was consistent, in that computed power radiated into the crew area agreed well with computed acoustic dissipation. However, due to the limited extent of the hull changes accomplished, the structural modifications provided no noise reduction and the damping treatment provided only slight noise reduction.