Honeycomb Core Damping Material Coating for Acoustic Attenuation
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Solution Overview
Problem
Existing panel structures for sound absorption, damping, or attenuation are not satisfactory in providing localized reinforcement, baffling, sealing, and thermal insulation while maintaining equivalent mechanical properties to conventional honeycomb core assemblies, and they often require foamable materials that react, activate, or melt to fill columnar cells, which is undesirable.
Innovation Solution
A reinforcement element with hollow columnar cells coated with a damping or attenuation material on the inner surface of the cell walls, allowing for seamless integration of sound damping materials within composite part manufacturing processes, maximizing acoustic performance and enabling localized application of sound absorption and damping properties without filling the cavities with foam.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If foamable materials are used to fill columnar cells for sound absorption and damping, then acoustic performance is improved, but manufacturing complexity increases and material consumption increases
Solution Approach 1:
The patent uses pre-formed porous absorptive material (such as acoustic foam or fibrous material) that is inserted into the hollow columnar cells of the honeycomb core. This eliminates the need for in-situ foam expansion and chemical reactions, simplifying the manufacturing process while maintaining acoustic performance. The porous structure of the material provides sound absorption and damping without requiring additional processing steps.
Solution Approach 2:
The absorptive material is prepared and positioned in advance (pre-formed) before being inserted into the honeycomb cells. This preliminary preparation allows for easier handling, precise placement at key locations, and integration into the composite manufacturing process without requiring on-site foam expansion or activation, thereby reducing manufacturing complexity.
2Object-affected harmful factors
If damping material is applied as a sheet on the outside of the panel, then sound absorption and damping are provided, but material consumption increases and weight increases
Solution Approach 1:
The damping material is nested within the hollow columnar cells of the honeycomb core structure, utilizing the existing void space rather than adding external layers. This nesting approach provides sound absorption and damping functionality without increasing the overall panel dimensions or requiring additional external material, thereby reducing weight and material consumption.
Solution Approach 2:
The damping material is selectively placed within specific columnar cells at key locations where sound absorption and damping are most needed, rather than applying material uniformly across the entire panel surface. This localized application optimizes acoustic performance while minimizing material consumption and weight.
3Volume of stationary object
If damping material is integrated inside the panel structure between face sheets, then volume is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The damping material is divided into discrete portions that fit into individual columnar cells of the honeycomb core. This segmentation allows for easier handling and placement of small, manageable material units, reducing the precision requirements compared to placing large continuous material layers. Each cell acts as a separate compartment that guides material placement.
Solution Approach 2:
The use of porous absorptive material with flexible, compressible properties allows for easier insertion into the hollow cells without requiring extremely tight tolerances. The material can be compressed during insertion and then expands to fill the cell, accommodating variations in manufacturing dimensions while maintaining effective sound absorption.
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 approach enhances the composite loss factor to weight ratio, improving acoustic performance and allowing for flexible embedding of damping materials at key locations, thereby optimizing sound attenuation and reinforcement while maintaining structural integrity and reducing material consumption.
Implementation Method 1
a reinforcement element comprising cell walls forming an array of hollow columnar cells, wherein each columnar cell comprises a cavity which is surrounded by cell walls, and wherein the reinforcement element comprises at least one coated columnar cell comprising a cavity which is surrounded by cell walls, wherein an inner surface of a cell wall towards the cavity of the at least one coated columnar cell is at least partially covered with a layer of a damping or attenuation material
Data Source
AI summary
The invention relates generally to a panel structure that incorporates one or more panels and a material for providing reinforcement, baffling, sealing, sound absorption, damping or attenuation, thermal insulation, combinations thereof or the like.