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A method for identifying common and unique issues in body in white dynamic stiffness based on modal contribution
Feitan Peng1, Luteng Chen2, Junyi Ye2
1SERES Automobile Co., Ltd, Chongqing, 402247, China. feitan.peng@foxmail.com.
Scientific Reports
|April 8, 2025
Summary
This study introduces modal contribution analysis to identify common or unique causes of poor dynamic stiffness in car bodies. Early distinction enhances Noise, Vibration, and Harshness (NVH) optimization efficiency.
Area of Science:
- Automotive Engineering
- Structural Dynamics
- Vibration Analysis
Background:
- Inadequate dynamic stiffness in car body connection points is a significant issue.
- Existing methods for diagnosing stiffness problems lack efficiency in distinguishing common vs. unique causes.
Purpose of the Study:
- To propose and validate a method for assessing whether inadequate dynamic stiffness stems from common or unique modal contributions.
- To enhance the efficiency of Noise, Vibration, and Harshness (NVH) optimization in vehicle bodies.
Main Methods:
- Modal contribution analysis was developed to differentiate between common and unique sources of dynamic stiffness issues.
- A case study on a body-in-white's front engine compartment attachment point was used for validation.
- Operational Deflection Shape (ODS) analysis was considered for unique issues.
Main Results:
- Common issues related to overall modes in the low-frequency range (54/58/74 Hz) were identified in the case study.
- Modal contribution analysis confirmed a specific engine compartment breathing mode as a common issue.
- The study demonstrated the method's ability to identify the source of dynamic stiffness problems.
Conclusions:
- Early identification of common versus unique dynamic stiffness issues is crucial for efficient NVH optimization.
- Modal contribution analysis provides a robust method for this identification.
- Frequency avoidance for common issues and ODS for unique issues are recommended optimization strategies.
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