Excitation force analysis of a powertrain based on CAE technology

Abstract

The excitation force of a powertrain is one of major sources of interior noise in a vehicle. This paper presents a novel approach to predict the interior noise caused by the vibration of the powertrain by using the hybrid TPA (transfer path analysis) method. Although the traditional transfer path analysis (TPA) is useful for the identification of powertrain noise sources, it is difficult to modify the structure of a powertrain by using experiments for the reduction of vibration and noise. In order to solve this problem, the vibration of the powertrain in a vehicle is numerically analyzed by using the finite element method (FEM). The vibration of the other parts of the vehicle is investigated by using experiments based on vibrato-acoustic transfer function (VATF) analysis. These two methods are combined for the prediction of interior noise caused by a powertrain. Throughout this research, two papers are presented. This paper presents a simulation of the excitation force of the powertrain exciting the vehicle body based on numerical simulation. The other paper presents a prediction of interior noise based on the hybrid TPA, which uses the VATF of the car body and the excitation force predicted in this paper.

Prediction of interior noise by excitation force of the powertrain based on hybrid transfer path analysis

“…Figure 6 shows the direct comparison between the measured exciting forces and the simulated exciting force, which is obtained by numerical analysis for the FE model of a powertrain based on the hybrid TPA (Kim et al, 2008). In previous work, the simulated excitation force was validated indirectly by comparing the measured displacements with the simulated displacement at the mount brackets (Kim et al, 2008). According to these results, both forces increase with the increase of the rotation speed of the crankshaft.…”

“…Hybrid TPA uses the simulated exciting force instead of the measured exciting force. The simulated exciting force is calculated by numerical analysis for the FE model of a powertrain (Kim et al, 2008) as shown in Figure 2. The advantage of hybrid TPA is the possibility of modifying the powertrain structure because it uses the FE model of a powertrain.…”

“…The complex dynamic stiffness as shown in Figure 4 and operational displacement are used for the estimation of the measured excitation force by using equation (3). Figure 6 shows the direct comparison between the measured exciting forces and the simulated exciting force, which is obtained by numerical analysis for the FE model of a powertrain based on the hybrid TPA (Kim et al, 2008). In previous work, the simulated excitation force was validated indirectly by comparing the measured displacements with the simulated displacement at the mount brackets (Kim et al, 2008).…”

Multibody Simulation for the Vibration Analysis of a Turbocharged Diesel Engine

“…The applied external forces come from the pressure cycle of the combustion gases [25]: from Figure 1 it is possible to appreciate the cycle variations at different regimes. All the forces of an inertial nature are calculated internally by the code according to the actual speeds and accelerations of the bodies.…”

Theoretical and experimental evaluation of performance of CNG engine and pistons fatigue lives employing modified fatigue criteria

“…Therefore, predicting the consequences is a vital task in the design stage. Piston as a key component of the engine that is vulnerable to severe cyclic and transient thermal and mechanical loads can be directly affected by the mentioned conversion [1,2].…”