Approaches to Reduce Truck Beaming

Truck beaming is the first order, full-vehicle vertical bending vibration mode. The vertical vibration of chassis frame rail predominately determines it. Rear axle input is the major source of beaming. This paper summarizes the possible approaches to minimize the vibration, including aligning axle with the rear beaming node, aligning the front beaming node with the response location or driver's seat attachment, and increasing beaming frequency. By changing its material property, beaming frequency is varied without significant change in mode shape: increasing the Young's module by 10 percent, the peak vertical frequency response could be reduced by about 10 percent while its beaming frequency is increased by about 5 percent. By adding a constant mass at vehicle end, the rear beaming node is shifted toward the axle: the beaming response is minimized when the rear beaming node is at the rear axle by adding 10 kg mass at the end of the frame rail. By adding a constant mass at the driver seat, the front beaming node is shifted toward the driver's seat: the peak beaming response is reduced by more than 30 percent when the distance between beaming node and seat attachment is reduced by 400 mm from adding 30 kg mass at the seat attachment. It is concluded that, without any active control strategy, truck beaming vibration could be minimized using the three approaches. Of them, aligning the rear axle with the rear beaming node is the most effective.