Composite Constrained Layer Damping for Thin Vehicle Panels
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Solution Overview
Problem
Conventional materials for damping acoustic vibrations in vehicles, such as those made from wood or metal, lack structural and mechanical integrity, limiting their effectiveness in reducing noise while maintaining performance.
Innovation Solution
A composite article comprising two fibre-reinforced constraining layers and a viscoelastic damping layer, where the constraining layers are made from materials like glass fibre-reinforced epoxy or urethane acrylate resin, and the damping layer includes thermoplastic resin and elastomer materials, allowing for efficient energy dissipation and improved structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional damping materials are made from wood or metal, then acoustic damping is achieved, but structural and mechanical integrity is insufficient
Solution Approach 1:
The patent applies composite materials by combining fibre-reinforced polymer matrices (for structural integrity) with viscoelastic damping materials (for vibration damping). The constraining layers use fibre-reinforced composites such as glass fibre, carbon fibre, or aramid fibre embedded in polymer matrices like epoxy or polyurethane, creating a multi-phase composite structure that simultaneously provides mechanical strength and acoustic damping performance.
2Object-affected harmful factors
If damping material thickness is increased to improve damping performance, then acoustic quieting is enhanced, but overall article thickness increases
Solution Approach 1:
The patent uses composite materials with viscoelastic properties that provide high damping efficiency per unit thickness. The fibre-reinforced polymer composite structure enables effective vibration damping with reduced material thickness compared to conventional homogeneous damping materials, achieving acoustic quieting while maintaining a compact overall article thickness suitable for vehicle body panels.
Solution Approach 2:
The patent optimizes the thickness parameters of both the constraining layers and the damping layer within specific ranges (constraining layers: 1-5 mm each, damping layer: 1-10 mm) to achieve the desired balance between damping performance and overall thickness. By adjusting these dimensional parameters, the article provides effective acoustic damping while maintaining a thickness of 6-50 mm that is suitable for direct use as vehicle body or floor panels.
3Reliability
If fibre-reinforced composite materials are used for constraining layers, then structural integrity is improved, but manufacturing complexity increases
Solution Approach 1:
The patent employs fibre-reinforced polymer composite materials for the constraining layers, where fibres (glass, carbon, or aramid) are embedded in a polymer matrix (epoxy, polyurethane, or polyester). This composite structure provides enhanced structural integrity, stiffness, and strength while maintaining manufacturability through established composite fabrication processes such as layering, molding, and curing.
Solution Approach 2:
The patent specifies thickness parameters for the constraining layers (1-5 mm) that balance structural requirements with manufacturing feasibility. These controlled dimensional parameters enable the fibre-reinforced composites to be manufactured using conventional processes while achieving the necessary structural performance for vehicle applications.
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 article achieves effective vibration damping with improved structural and mechanical performance, enabling its use as a body or floor panel in vehicles while maintaining acoustic quieting, and has a reduced thickness compared to traditional materials.
Implementation Method 1
a damping layer disposed between the first and second constraining layers, wherein the damping layer comprises a viscoelastic material
Implementation Method 2
Energy, e.g. vibrational energy, is dissipated in the viscoelastic material, typically through shear strain converting to heat energy
Implementation Method 3
the first and second constraining layers each independently comprise a fibre-reinforced composite material
Implementation Method 4
In constrained layer damping, a damping material is sandwiched between two stiff sheets that do not themselves have damping properties. Energy is dissipated as a result of shear deformation of the damping material when the stiff sheets bend and/or flex during vibration
Data Source
AI summary
An article for damping vibrations by constrained layer damping comprising: a first constraining layer; a second constraining layer; and a damping layer disposed between the first and second constraining layers, wherein the first and second constraining layers each independently comprise a fibre-reinforced composite material, wherein the first and second constraining layers each independently have a thickness from 1.5 to 5 mm, wherein the damping layer comprises a viscoelastic material, wherein the damping layer has a thickness from 1 to 10 mm and wherein the article has a thickness from 6 to 50 mm. The invention also relates to the use of said article for damping vibrations in a vehicle.