Noise, Vibration and Harshness (NVH) Study on Malaysian Armed Forces (MAF) Tactical Vehicle

Abstract

Noise, Vibration and Harshness (NVH) is the study and modification of the noise and vibration characteristics of vehicles, particularly cars and trucks. NVH parameters which consist of noise (unwanted sound), vibration (mechanical oscillation) and harshness (severity or discomfort of noise or vibration) need to be evaluated in order to improve comfort and safety levels for vehicle occupants. In this paper, NVH study was conducted on Malaysian Armed Forces (MAF) tactical vehicles in order to ensure that the vehicles meet the requirements of the Occupational Safety and Health Administration (OSHA) and Directive 2002/44/EC. The project aim was to identify the preferable solution that can improve the NVH parameters of the vehicles in accordance to the standard and test protocols. A 4x4 Troop Transporter vehicle which carried 8 persons at the rear cabin was used in the NVH testing. The vibration parameters studied are hand arm vibration (HAV), focussing on vibration on the steering wheels of the vehicle, and whole body vibration (WBV), focussing on vibration on the seats. For noise, it was measured at the driver cabin and rear cabin of the vehicles. From the results, the HAV value for driver during idle speed was found to be higher than the others velocity. For WBV, vibration value for passenger 1 in rear cabin was highest compared to the other WBV test points.

In-vehicle noise exposure among military personnel depending on type of vehicle, riding compartment and road surface

“…Our results of noise level in the driver’s cab compared with the canvas covered rear passenger compartment of heavy all-terrain truck were quite similar to the results by Aziz et al ,22 where the equivalent noise level in the rear passenger compartment was higher than in the driver’s cab. Contrary, the peak noise levels in the cab of DAF 4440 exceeded the parameters measured in the canvas covered rear compartment on both paved and off-road.…”

New regression model for predicting hand‐arm vibration (HAV) of Malaysian Army (MA) three‐tonne truck steering wheels

“…Overall, the level of HAV did not exceed the ELV, which is 5 ms −2 . Studies conducted by Aziz et al 1,13,18) proved that all the drivers they tested felt uncomfortable with the vibration generated by the different types of tested vehicles.…”

“…For example, Directive 2002/44/EC of the European Parliament 17) stipulates minimum standards for health and safety of workers exposed to HAV in terms of an exposure action value (EAV) and exposure limit value (ELV) associated with 8 h of daily exposure, in addition to requiring employers to reduce worker vibration exposure levels wherever it is practically possible. A previous study on Malaysian Armed Forces (MAF) tactical vehicles by Aziz et al 18) found that HAV is high in the driver's hands when the vehicle being driven is in the idle position, with the HAV value exceeding the EAV of 2.5 ms −2 . This occurs because vibration from the engine and vehicle, which is very high during the idle phase, is directly transferred to the steering wheel.…”

Study on the influence of sudden load at idle condition on vibration and vibration isolation performance of the engine mount system

“…Nowadays, people’s requirements for a car are not limited to its power and economy. The comfort of driving occupies an increasingly important position in the process when people purchase cars, and noise vibration harshness (NVH) performance is an important index to evaluate vehicle comfort (Aziz et al, 2012; Stefan et al, 2020). Excessive vibration would bring serious fatigue damage to the vehicle and greatly reduce the life of the vehicle.…”