Vehicle Floor Panel Structure for Suppressing NVH Vibration Modes
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Solution Overview
Problem
Existing vehicle-body structures experience adverse NVH performance due to vibrations transmitted from engines and suspensions, leading to increased cabin air vibration and resonance across entire panel regions.
Innovation Solution
A vehicle-body structure featuring a floor panel with a flange portion, a high-rigidity curved surface portion, and a lower-rigidity flat surface portion, where the flat surface portion is strategically designed to resonate and equipped with a vibration damping member, thereby suppressing overall panel vibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a floor panel with both curved surface portion and flat surface portion is used, then rigidity is improved by the curved portion, but the flat surface portion vibrates and induces integral vibration of the entire panel region, deteriorating NVH performance
Solution Approach 1:
The floor panel is segmented into three distinct regions: a flange portion at the periphery, a curved surface portion in the middle, and a flat surface portion at the center. This segmentation allows each region to have different rigidity characteristics and vibration behaviors, with the flat surface portion being isolated from inducing integral vibration of the entire panel.
Solution Approach 2:
Different portions of the floor panel are given different local qualities: the curved surface portion has high rigidity due to its curved geometry, while the flat surface portion has lower rigidity and is designed to vibrate independently. This local differentiation prevents the propagation of vibration across the entire panel while maintaining overall structural strength.
2Strength
If the entire region surrounded by frame members vibrates, then the area in which air is vibrated increases, leading to deterioration of NVH performance
Solution Approach 1:
The panel surface is segmented into curved and flat portions that vibrate independently, preventing the entire region from vibrating as one unit. This segmentation limits the area that can vibrate air, thereby reducing NVH issues while maintaining structural integrity through the curved portions and flange connections.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively reduces panel vibrations and improves NVH performance by dissipating vibration energy through the damping member, minimizing air vibration and enhancing acoustic radiation power reduction.
Implementation Method 1
a vibration damping member is provided on the flat surface portion
Data Source
Figure 1
Figure 2
Figure 3(a)~3(b)
AI summary
The floor panel vibration is reduced by suppressing a mode in which an entire region surrounded by a plurality of frame members in a floor panel 10 vibrates, the floor panel 10 to which vibration is transmitted from an engine or/and a suspension via vehicle-body framework members includes: a flange portion 11, which is formed in a planar shape on panel outer peripheral edge and to which the vehicle-body framework members are joined along the panel outer peripheral edge; a curved surface portion 12 that is curved such that a place closer to a panel central side bulges out more to a lower side in a continuous manner from a panel-central-side edge portion 14 of the flange portion 11; and a flat surface portion 13 that extends to the panel central side from the panel-central-side edge portion 14 of the curved surface portion 12 in a continuous manner.