Acoustically Resistive Structure Flat Edge Consolidation

Solution Overview

Problem

The existing acoustically resistive structures in sound-absorption panels suffer from curved strip edges and domed faces, which disrupt acoustic treatment and reduce mechanical strength due to reduced contact surface areas between strips and filaments.

Innovation Solution

A method involving a first layer of reinforcing fibers consolidated with a high-temperature thermoplastic resin, followed by cutting openings to create an interlayer with flat edges, and a second layer consolidated with a lower-temperature resin to form a non-perforated external layer bound to the interlayer, ensuring flat surfaces and optimized acoustic treatment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If strips of material are consolidated with thermoplastic resin in an autoclave, then the strips are bonded together to form a structure, but the edge faces become curved and the opposite faces become domed, disrupting acoustic treatment and reducing contact surface area

Engineering Contradiction:

Improvemechanical strength of bond between strips and filamentsVSAvoidflatness and uniformity of strip edges and faces

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The consolidation process is divided into two separate steps: first consolidating the strips with the first thermoplastic resin, then consolidating the external layer with the second thermoplastic resin. This segmentation allows each consolidation step to be optimized independently, preventing the deformation that occurs when both layers are consolidated simultaneously.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention uses two different thermoplastic resins with different consolidation temperatures. The first resin has a lower consolidation temperature and is used to consolidate the strips, while the second resin has a higher consolidation temperature and is used for the external layer. This parameter change allows the strips to be consolidated at a lower temperature, preventing the thermal deformation that occurs with high-temperature consolidation.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If a single consolidation step is used for both strips and external layer, then the process is simpler, but the strip faces become domed reducing contact surface area for filament attachment

Engineering Contradiction:

Improvesimplicity of consolidation processVSAvoidcontact surface area between strips and filaments

Core Design Contradiction:

Ease of manufactureVSArea of stationary object

Solution Approach 1:

The consolidation process is divided into two separate steps: first consolidating the strips with the first thermoplastic resin, then consolidating the external layer with the second thermoplastic resin. This segmentation allows each consolidation step to be optimized independently, preventing the deformation that occurs when both layers are consolidated simultaneously.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention uses two different thermoplastic resins with different consolidation temperatures. The first resin has a lower consolidation temperature and is used to consolidate the strips, while the second resin has a higher consolidation temperature and is used for the external layer. This parameter change allows the strips to be consolidated at a lower temperature, preventing the thermal deformation that occurs with high-temperature consolidation.

Inventive Principle:

Principle #35Parameter changes

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 method results in improved acoustic performance and increased mechanical strength by maintaining flat strip edges and uniform spacings, enhancing the bond between strips and internal layers.

Implementation Method 1

a first consolidation step of consolidating the first layer of reinforcing fibres embedded in a first thermoplastic resin having a first melting point

Methodology Applied

Scientific EffectMelting: Melting

Implementation Method 2

consolidating the first layer of reinforcing fibres embedded in a first thermoplastic resin

Methodology Applied

Scientific EffectThermal bonding:

Implementation Method 3

a second consolidation step of consolidating the second layer of reinforcing fibres embedded in a second thermoplastic resin having a second consolidation temperature lower than the first melting point of the first resin

Methodology Applied

Scientific EffectMelting: Melting

Implementation Method 4

consolidating the second layer of reinforcing fibres embedded in a second thermoplastic resin

Methodology Applied

Scientific EffectThermal bonding:

Data Source

PatentUS11325323B2Method for producing an acoustically resistive structure, acoustically resistive structure thus obtained, and sound-absorption panel comprising said acoustically resistive structure

Publication Date: 2022.05.10 AIRBUS OPERATIONS (SAS)

AI summary

A method for producing an acoustically resistive structure includes the steps of creating, consolidating and cutting a first layer of reinforcing fibres embedded in a first thermoplastic resin having a first melting point so as to obtain an interlayer, a step of laying a second layer of reinforcing fibres against a first face of the interlayer, a second consolidation step of consolidating the second layer of reinforcing fibres embedded in a second thermoplastic resin having a second consolidation temperature lower than the first melting point of the first resin so as to obtain a non-perforated external layer bound to the interlayer, a step of perforating the external layer and a step of laying an internal layer on a second face of the interlayer. An acoustically resistive structure obtained from the method as well as a sound-absorption panel including such an acoustically resistive structure are also described.