MBS-FEM Co-Simulation Approach to Assess Strength of Automotive Chassis Components

Automotive chassis components are considered as safety critical components and must meet the durability and strength requirements of customer usage. The cases such as the vehicle driving through a pothole or sliding into a curb make the design (mass efficient chassis components) challenging in terms of the physical testing and virtual simulation. Due to the cost and short vehicle development time requirement, it is impractical to conduct physical tests during the early stages of development. Therefore, virtual simulation plays the critical role in the vehicle development process. This paper focuses on virtual co-simulation of vehicle chassis components. Traditional virtual simulation of the chassis components is performed by applying the loads that are recovered from multi-body simulation (MBD) to the Finite Element (FE) models at some of the attachment locations and then apply constraints at other selected attachment locations. In this approach, the chassis components are assessed separately from the vehicle environment. The MBD model predicts the dynamic behavior of the motions of the flexible bodies (subframe, control arms, knuckle, wheel, yoke, tie rods, etc.) that are connected to each other through kinematic constraints / joints / contacts. The loads from MBD model do not consider the energy loss due to plastic deformation of the chassis components when the vehicle goes through a pothole or slides to a curb. To accurately predict chassis component performance, an integrated vehicle system model is needed. An FE-based full vehicle model has its challenges: (1) time consuming to build, (2) model is too large if all kinematic constraints / joints / contacts / tires are considered, or (3) cannot “drive” through the desired road. A tightly coupled co-simulation between MBD and FE model can overcome these inherent challenges. Co-simulation using Simpack and Abaqus is an ideal combination of solvers which combines the benefits of a high fidelity, detailed system level response and highly accurate Abaqus non-linear solution using plasticity and damage material models. This paper depicts case studies of Simpack-Abaqus co-simulation for chassis components under various extreme loading events performed.