Improving the dynamic characteristics of body-in-white structure using structural optimization

Area of Science:

• Automotive Engineering
• Structural Dynamics
• Computational Mechanics

Background:

• The dynamic behavior of a car's body-in-white (BIW) structure critically impacts noise, vibration, harshness (NVH), and crashworthiness.
• Improving BIW dynamic characteristics is essential to prevent failures related to resonance and fatigue.

Purpose of the Study:

• To enhance existing torsion and bending modes of BIW structures using structural optimization under dynamic loads.
• To achieve target vibration specifications without compromising the overall mass and stiffness of the structure.

Main Methods:

• Topology optimization was employed to identify critical structural locations using mass and natural frequencies as design variables.
• Size optimization was subsequently used to determine and adjust the target thickness of individual components at identified critical regions.
• A combined approach integrating topology and size optimization was proposed for an improved design modification process.

Main Results:

• The study identified crucial points within the BIW structure for reinforcement to modify natural frequencies.
• Optimization steps suggested specific design modifications, including altering component thicknesses, to meet vibration targets.
• The proposed method demonstrated the potential to improve dynamic characteristics while maintaining structural stiffness.

Conclusions:

• Structural optimization techniques, particularly when combined, offer an effective strategy for refining BIW dynamic behavior.
• Targeted reinforcement and thickness adjustments can significantly improve NVH and crashworthiness performance.
• The research provides a pathway for designing more robust and dynamically superior automotive structures.