Multilayer Nonwoven Interleaf for Composite Damping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Advanced composite materials used in aerospace applications face limitations in acoustic and vibrational damping performance, often requiring additional treatments that increase cost, weight, and complexity, while existing solutions like viscoelastic damping materials have limitations in mechanical performance and manufacturing flexibility.
Innovation Solution
A structural composite material with a multilayer nonwoven interleaf having a compositional gradient, where the outer layers are more interpenetrated with resin than the core, creating a controlled interlaminar structure that enhances damping and mechanical properties without the need for plasma treatment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If advanced composite materials are used to achieve high strength-to-weight and stiffness-to-weight ratios, then mechanical strength and stiffness are improved, but acoustic and vibration damping performance deteriorates
Solution Approach 1:
The patent applies composite materials by combining fiber-reinforced polymer matrix composites with a multilayer nonwoven interleaf structure. The interleaf comprises different fiber types (e.g., aramid, glass, carbon) and resin systems that work together to provide both structural integrity and damping performance. This composite approach allows the material to simultaneously achieve high strength-to-weight ratio and improved acoustic/vibration damping that neither component could achieve alone.
Solution Approach 2:
The patent implements local quality through the multilayer nonwoven interleaf structure with varying fiber compositions and resin impregnation levels in different layers. The interleaf has a gradient structure where outer layers differ from inner layers in terms of fiber type, density, and resin content, allowing different regions to perform different functions: some layers optimize for mechanical strength while others optimize for damping performance.
2Reliability
If plasma treatment is applied to improve acoustic and vibrational damping properties, then damping performance is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent applies self-service by designing the multilayer nonwoven interleaf structure to inherently provide damping functionality through its composition and architecture, eliminating the need for external plasma treatment. The specific arrangement of fibers and resin systems within the interleaf creates the necessary damping properties through material selection and structural design rather than requiring additional surface modification processes.
Solution Approach 2:
The patent extracts the damping function from the plasma treatment process and integrates it directly into the interleaf material structure. Instead of applying plasma treatment as a separate post-processing step to achieve damping, the damping properties are built into the interleaf itself through careful selection of fiber types, layer configuration, and resin impregnation, thereby removing the need for the complex plasma treatment step.
3Reliability
If viscoelastic damping materials are used to improve acoustic and vibrational damping, then damping performance is improved, but mechanical performance and manufacturing flexibility deteriorate
Solution Approach 1:
The patent uses composite materials by combining fiber-reinforced polymer matrices with a multilayer nonwoven interleaf containing different fiber types (aramid, glass, carbon) and resin systems. This composite structure provides both the mechanical strength needed for structural applications and the damping performance required for acoustic and vibration control, avoiding the mechanical performance limitations of pure viscoelastic materials.
Solution Approach 2:
The patent applies parameter changes by varying the fiber type, fiber diameter, layer thickness, and resin impregnation level across different layers of the interleaf. These parameter variations allow optimization of both mechanical properties and damping characteristics in different regions of the interleaf, achieving a balance between strength and damping that uniform viscoelastic materials cannot provide.
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
This solution achieves significant improvements in noise/vibration attenuation and delamination strength, reducing weight and cost while maintaining or improving mechanical properties, and can be integrated into existing manufacturing processes for aerospace structures.
Implementation Method 1
upon curing the interleaf comprises a resin interpenetration gradient between the nonwoven material in the core and outer portions in the z direction
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Composite materials having favorable acoustic and vibration damping properties, while maintaining or improving other composite mechanical properties, include an interleaf layer comprising at least two different nonwoven materials in a specific sequence such that a gradient is formed in the z direction upon curing or an interleaf with a compositional gradient within its structure such that a resin interpenetration gradient is achieved upon curing. Composite materials that contain multilayered nonwoven interleaves are useful, for example, in structures found in aircrafts, such as fuselage skins, stringers and frames. Also contemplated are methods of making the composite material and the structures and aircrafts that contain the composite material.