Motorcycle Engine Vibrations Prediction for Inertia Loads Using Multi Body Dynamics Calculations

Motorcycles are a preferred means of transportation in most of the countries due to its economic factor and ease in travelling. Rider comfort is an important aspect while designing a vehicle. Rider comfort is often compromised by unwanted vibrations experienced at human interface points also called as tactile points. These unwanted vibrations also affect rider’s motorcycle control and overall health. There are two major source of vibrations in a motorcycle that is engine & road inputs.

In current study, a method is being explored to predict engine induced vibrations. Engine induced vibrations at various locations are simulated through multi body dynamics (MBD) and finite element (FE) simulation methods at vehicle level. Motorcycle model comprising of engine, frame and subassemblies are modeled in FE tool and then condensed to be used in MBD tool. Piston assembly, connecting rod, bearings and engine mounts are modeled in MBD tool. Vibration response resulting from unbalanced inertia forces and moments are simulated at engine locations. Simulated vibration levels are correlated with test results to confirm robustness of proposed method.