Acoustic Simulation of Cabin for Off-highway Machinery

Abstract

The reduction interior noise is an important concern in noise, vibration and harshness (NVH) for different reasons. Noise and vibration of the passenger cabin are the signature points to the overall impression of the vehicle quality. Very high noise and vibrations at the drivers ear position, make noise and vibration a key issue. Long exposure to high noise levels are major factors of risk to worker health and safety. Thus it is very important to study the noise generated inside the cabin. Experimental method is carried out but it is very expensive and time consuming. This project work is based on the development of predictive finite element acoustic structural analysis to study the Vibro-acoustic behaviour of the excavator cabin. The displacement response of cabin under the external force excitation is analysed between 0 Hz and 300 Hz. The displacement response is mapped to acoustic cavity surface by the normal surface interaction. The distribution of internal acoustic field is calculated and sound pressure level response is obtained at the driver’s ear. The methodology has been established for acoustic analysis of cabin and sound pressure level has been reduced by 20dB.