Interior Noise Reduction of Construction Equipment Vehicle Through Structure-borne Noise Reduction Strategy

One can witness the constant development and redevelopment of cities throughout the world. Construction equipment vehicles (CEVs) are commonly used on the construction site. However, the noise pollution from construction sites due to the use of CEV has become a major problem for many cities. The construction equipment employed is one of the main causes of these elevated noise levels. The construction workers possibly are face a potential risk to their auditory health and well-being due to the noise levels they are exposed to. Different countries have imposed exterior and operator noise limits for construction equipment vehicles, enabling them to control noise pollution from CEVs. In this study, the operator ear level noise of the identified vehicle is 6 dB(A) higher than the regulatory limit in dynamic conditions, when tested as per ISO 6396. It was a tough time for the NVH engineer to reduce the interior noise level of the vehicle. Surprisingly, the steering unit and radiator fan were identified as the major dominant sources rather than typical conventional sources like powertrain, intake, and exhaust. Initially, the noise source identification technique was used to identify the dominant sources for increasing the interior noise of the test vehicle. It was observed that the transfer of structure-borne to the cabin was the major issue with the vehicle. It was foremost required to address the issue without compromising the overall performance of the vehicle other than NVH. Individual sources of noise were analysed in detail, and optimizations were made to minimize the noise at the source. As a result, the significant noise reduction achieved inside the vehicle and the overall in-cab noise level for the vehicle became a new benchmark in the market.