Multibody Dynamics Cosimulation for Vehicle NVH Response Predictions

At various milestones during a vehicle’s development program, different CAE models are created to assess NVH error states of concern. Moreover, these CAE models may be developed in different commercial CAE software packages, each one with its own unique advantages and strengths. Fortunately, due to the wide spread acceptance that the Functional Mock-up Interface (FMI) standard gained in the CAE community over the past few years, many commercial CAE software now support cosimulation in one form or the other. Cosimulation allows performing multi-domain/multi-resolution simulations of the vehicle, thereby combining the advantages of various modeling techniques and software.

In this paper, we explore cosimulation of full 3D vehicle model developed in MSC ADAMS with 1D driveline model developed in LMS AMESim. The target application of this work is investigation of vehicle NVH error states associated with both hybridized and non-hybridized powertrains. AMESim is responsible for generating the engine excitation, dampers, and detailed transmission, along with modeling the control strategy for powertrain component operations. Engine block, engine mounts, driveshaft, differential-axle unit, suspension, half-shafts, wheels, and body are modeled in ADAMS and imported as a functional mock-up unit in AMESim. Several key steady-state and transient error states are investigated. In particular, we look at the vibration response at the customer touch points due to transient phenomena generated by engine. Although a specific application of cosimulation is demonstrated in this paper, the methodology is general and can be used to simulate any powertrain system – vehicle combination. Hence data transfer between the co-simulating software is described and effects of key parameters, such as integrator type, time steps, and communication interval, on the quality of results are also investigated.