On the Application of Vibration Absorbers Based on Acoustic Black Holes to the Handlebar of a Low-Cost Motorcycle

This chapter deals with one of the main Noise, Vibration, and Harshness (NVH) problems on low-cost motorcycles, that is, the handlebar submitted to exogenous and endogenous vibrations generated by the engine operation and transmitted to rider and passengers. Therefore, it is proposed the application of passive vibration absorbers on both sides of the handlebar, whose designs and synthesis are based on the Acoustics Black Hole methodology. In particular, a low-cost motorcycle with a 150 cc, unbalanced single-cylinder and air-cooled engine is considered as a case study for the numerical and experimental modal analysis of the handlebar and all the structural dynamics involved on the human–machine–structure interaction. Both vibration absorbers are sharp-end beam-like counterweights placed at the ends of the handlebar, which are simple and inexpensive solutions. Some numerical modeling using finite element methods and experimental modal analysis techniques are described to evaluate the dynamic performance of the implementation on the motorcycle, for different operating conditions.