Abstract
The purpose of this paper is to establish a method for predicting the idle vibration of tractor steering, fender and floor systems in the engine-idling condition by using forced response analysis. At first phase, an analytical FE model of tractor is constructed. An MBD model of complete engine with piston, crankshaft, connecting rod and main journal bearing has been created using the commercially available multi body dynamics tool with the following inputs like inertia, No. of cylinders and geometric data etc. By using the combustion parameters – pressure vs crank angle curve corresponding to the Idle Excitation measured on the test as an input for the MBD model and the output forces are obtained at the main journal bearing locations, cylinder-head, piston TDC and BDC. These derived forces from MBD used as an input for the full vehicle finite element model, forced response analysis has been executed using the commercially available NVH computational code to predict the vibratory amplitudes on the steering, fender and floor corresponding to the idle excitation. Furthermore, this model is employed as a tool in identifying top contributing paths to the vibration levels at touch points through transfer path analysis. Identified paths are optimized for attenuation of the vibration levels. Good agreements are found between the analytical and experimental data.