Shock & Jerk phenomena are transient phenomena excited by torque variations in the driveline. They are dominated by the rigid body modes of the powertrain. This paper proposes approaches to optimize the powertrain-mounting layout for Shock & Jerk throughout vehicle development. In the concept stage, a simple model of the powertrain on its mounts, loaded with simplified synthetic load cases is proposed, with optimization strategies based on modal alignment, minimization of the force transfer, etc. Later in the development cycle, a full vehicle model with rigid powertrain is proposed. Load cases derived from test lead to accurate simulation results. When the optimization of the torsional vibration transfer through the drive shafts is included, a detailed powertrain and driveline model including the internal parts is required. This allows simulating the entire “sparkplug to seat rail” path.
