Constrained-Layer Damping Material for Lightweight Vehicle Panels
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Solution Overview
Problem
Existing vibration damping materials in vehicles face challenges in achieving high vibration damping performance while minimizing weight and maintaining rigidity, particularly in constraint type structures where the constraining plate is thick and heavy.
Innovation Solution
A vibration damping material with a viscoelastic layer and a constraining layer having a strain ratio εa/εb of 0<εa/εb<1, where εa is the strain on the surface opposite to the viscoelastic layer and εb is the strain on the surface in contact with it, utilizing a multilayer structure with tubular cells and film layers to enhance damping performance and reduce weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thick metal plate is used as the constraining plate in a constraint type vibration damping structure, then the vibration damping performance is improved, but the weight increases
Solution Approach 1:
The patent uses a composite constraining plate consisting of a base plate and a reinforcement plate with a specific configuration. The reinforcement plate has a lower density than the base plate and is positioned to optimize the strain distribution. This composite structure achieves high vibration damping performance through the synergistic effect of the two materials while reducing the overall weight compared to a solid metal plate of equivalent thickness.
Solution Approach 2:
The reinforcement plate is strategically positioned on the constraining plate to create local quality variations. By placing the lower-density reinforcement material in specific regions where it optimizes the strain ratio between the inner and outer surfaces, the structure achieves enhanced vibration damping performance in critical areas without uniformly increasing weight across the entire plate.
2Strength
If a thick metal plate is used as the constraining plate, then the rigidity is improved, but the weight increases
Solution Approach 1:
The composite structure combining base plate and reinforcement plate with different densities and mechanical properties optimizes rigidity while controlling weight. The reinforcement plate's strategic positioning enhances the overall stiffness of the constraining plate in directions critical for vibration damping, achieving high rigidity without the weight penalty of a uniformly thick metal plate.
Solution Approach 2:
The patent optimizes parameters including the thickness of the base plate and reinforcement plate, the density ratio between materials, and the positioning of the reinforcement plate to achieve the desired strain ratio. By carefully adjusting these parameters, the structure achieves optimal rigidity-weight balance for effective vibration damping performance.
3Weight of moving object
If a thin constraining plate is used, then the weight is reduced, but the vibration damping performance decreases
Solution Approach 1:
The composite constraining plate structure allows for a thinner overall design while maintaining or enhancing vibration damping performance. The reinforcement plate, positioned to optimize strain distribution, compensates for the reduced thickness of the base plate, enabling weight reduction without sacrificing the strain ratio necessary for effective vibration damping.
4Weight of moving object
If a thin constraining plate is used, then the rigidity is reduced, but the weight is reduced
Solution Approach 1:
The reinforcement plate in the composite structure provides localized stiffness enhancement that compensates for the reduced thickness of the base plate. This allows the overall structure to maintain adequate rigidity for vibration damping applications while achieving significant weight reduction compared to a solid metal plate of equivalent performance.
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 configuration improves vibration damping performance and reduces weight by using a constraining layer with a resin material instead of a thick metal plate, achieving high rigidity and effective noise reduction.
Implementation Method 1
a viscoelastic layer and a constraining layer provided on one surface of the viscoelastic layer
Implementation Method 2
vibration damping performance (sound insulation performance)
Data Source
AI summary
There is provided a vibration damping material capable of exhibiting excellent vibration damping performance and of reducing its own weight while having high rigidity. The vibration damping material of the present invention used so as to be installed on a panel 300 of a vehicle includes a viscoelastic layer 200 and a constraining layer 100 provided on one surface of the viscoelastic layer 200, wherein a relationship between a strain εa and a strain εb is 0<εa/εb<1, the strain εa being a strain on a surface 100a of the constraining layer 100 on the opposite side to the viscoelastic layer, and the strain εb being a strain on a surface 100b of the constraining layer 100 on a side in contact with the viscoelastic layer.