How do you analyze and mitigate torsional vibration in the powertrain?

Torsional vibration analysis involves: Modeling the complete powertrain as a lumped-mass spring-damper system, calculating natural frequencies and mode shapes, analyzing forced response to engine excitation orders, evaluating resonance conditions across the operating range, and designing countermeasures. Mitigation strategies include dual-mass flywheel (DMF) for low-frequency isolation, torsional dampers in torque converters, pendulum absorbers tuned to specific orders, clutch damper optimization, and operational avoidance of critical speeds. Analysis tools include AVL EXCITE, ROMAX, or GT-SUITE. Validation uses torsional accelerometers throughout the driveline.