Additive Sound Damping Panels via 3D Printing

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Solution Overview

Problem

Conventional sound damping structures are often heavy, bulky, and not specifically designed for sound absorption, and their manufacturing methods are expensive and complicated.

Innovation Solution

The method involves determining desired sound absorption properties, designing a corresponding three-dimensional sound absorbing geometry, constructing a 3D CAD model, and additively manufacturing a sound absorbing panel with an array of pyramids to fit specific locations, such as aircraft interiors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional damping materials (drywall, foam sheets, honeycomb panels) are used to absorb sound, then sound absorption performance is improved, but the structures become heavy and bulky

Engineering Contradiction:
Improvesound absorption performanceVSAvoidweight of sound damping structure
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent employs porous open-cell foam materials as the core damping material. The porous structure allows sound waves to penetrate and be absorbed while maintaining lightweight properties. The foam cells are specifically designed to be open and interconnected, enabling effective sound energy dissipation through viscous losses and thermal conduction without requiring dense solid material

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent creates composite sound damping structures by combining foam material with fabric layers and adhesive systems. The composite construction integrates the sound-absorbing foam core with fabric coverings that provide structural integrity and aesthetic finish, achieving optimal balance between sound absorption performance and overall structure weight

Inventive Principle:
Principle #40Composite materials

2Reliability

If the density and thickness of damping materials are increased to improve sound absorption, then sound absorption performance is improved, but the structures become heavier and more bulky

Engineering Contradiction:
Improvesound absorption performanceVSAvoidvolume of sound damping structure
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent applies different material densities and foam cell structures at different locations within the damping panel. The foam density varies locally to optimize sound absorption for specific frequency ranges and incident angles, rather than using uniform high-density material throughout. This localized optimization achieves effective sound damping with reduced overall material volume

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent transitions from conventional two-dimensional flat panels to three-dimensional sculpted and contoured damping structures. The foam material is shaped with varying thicknesses, curves, and geometric forms that enhance sound absorption through multiple reflections and path lengths, achieving superior performance without increasing overall volume

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If honeycomb panels are used to absorb sound in aircraft, then sound absorption is improved, but manufacturing complexity increases due to bonding and machine cutting requirements

Engineering Contradiction:
Improvesound absorption performanceVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple manufacturing operations into a single additive manufacturing process. The foam core, fabric layers, and adhesive bonds are all created in one continuous 3D printing operation, eliminating the need for separate bonding and cutting steps required by conventional honeycomb panel fabrication

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The additive manufacturing process creates self-bonding structures where the foam material is deposited with built-in adhesive properties, and the geometric interlocking features are printed directly into the structure. The fabric layers are applied and bonded in the same manufacturing run, creating a self-contained panel that requires no post-assembly operations

Inventive Principle:
Principle #25Self-service

4Ease of manufacture

If conventional damping materials are used without geometric design, then manufacturing is simpler, but sound absorption performance is reduced

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidsound absorption performance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent incorporates curved surfaces, spherical elements, and non-planar geometric features directly into the foam structure through additive manufacturing. These curved geometries scatter and reflect sound waves in multiple directions, increasing the path length and absorption opportunities, while the 3D printing process creates these complex curves as easily as straight lines

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 allows for the creation of lightweight, custom-tailored sound damping structures that efficiently absorb sound, reducing noise levels while minimizing manufacturing costs and lead time.

Implementation Method 1

geometric sound damping structures... absorb sound energy based on their geometric properties

Methodology Applied
Scientific EffectSound scattering: Scattering

Implementation Method 2

frequency zones of strong vibro-acoustic attenuation... good vibro-acoustic response

Methodology Applied
Scientific EffectAcoustic resonance: Resonance

Data Source

PatentEP3142105B1Geometric sound absorption via additive manufacturing
Publication Date: 2025.02.12 THE BOEING CO
  • EP3142105B1 patent drawingFigure 1
  • EP3142105B1 patent drawingFigure 2
  • EP3142105B1 patent drawingFigure 3

AI summary

Sound damping structures and methods for additively manufacturing composite structures having sound damping properties. In some embodiments, sound damping structures may be manufactured according to methods that may include selecting a desired sound damping geometry, inputting a three-dimensional computer-aided design model of the geometry into an additive manufacturing machine, and additively manufacturing a three-dimensional sound damping structure corresponding to the computer-aided design model.