Numerical modeling of mechanical properties of UAM reinforced aluminum hat sections for automotive applications

Structural lightweighting is a key initiative in the automotive sector due to regulatory, customer, and powertrain demands. This research focuses on reinforcing aluminum sheet metal in strategic locations using ultrasonic additive manufacturing (UAM), as guided through an iterative optimization and simulation process. Among the three models used, the most successful is the multi-step model (MSM) which simulates the forming of tailored blanks and the unloading processes to accurately map the hardening and the residual stress in hat and reinforcement sections. The MSM shows that approximately 65% of the mass can be saved by replacing a large gauged sheet metal hat section with a discretely reinforced hat section. Further increases in specific energy absorption (SEA) and additional mass savings can be expected when utilizing higher specific strength and specific stiffness materials for reinforcement such as titanium alloys, composites, or ceramic materials, all of which have been demonstrated with UAM.