Splice-Jointed Acoustic Panel for Low-Frequency Noise Attenuation
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Solution Overview
Problem
Existing structural panels for attenuating sound generated by aircraft propulsion systems are not optimized for effective noise reduction, particularly in terms of frequency range and structural integrity.
Innovation Solution
A structural panel design featuring a multi-segment core structure with vertically extending cavities and protrusions, laterally bonded at a complex splice joint, and a porous skin configuration to enhance noise attenuation and structural bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a structural panel uses a multi-segment core structure with complex splice joints, then noise attenuation effectiveness is improved, but manufacturing complexity increases
Solution Approach 1:
The core structure is divided into multiple discrete core structures that can be manufactured separately and then assembled through splice joints. Each core structure contains cavities that function as resonance chambers for noise attenuation, while the segmentation allows for modular manufacturing and assembly, reducing overall manufacturing complexity despite the complex joint design.
Solution Approach 2:
Protrusions from one core structure are inserted into recesses of adjacent core structures, creating a nested interlocking configuration. This nesting approach allows the complex splice joint geometry to be distributed across multiple components rather than requiring a single complex joint, facilitating manufacturing while maintaining noise attenuation performance.
2Strength
If the panel uses meshed protrusions at splice joints, then shear load resistance is improved, but manufacturing precision requirements increase
Solution Approach 1:
The protrusions and recesses are designed with asymmetric geometries that interlock in a specific orientation. This asymmetry creates a mechanically interlocking joint that resists shear loads through geometric constraint rather than relying solely on bonding strength, reducing the precision required for alignment during assembly while maintaining high shear resistance.
Solution Approach 2:
The splice joint geometry incorporates curved surfaces and rounded transitions in the protrusions and recesses. These curved features facilitate easier assembly by providing guidance during insertion while maintaining strong mechanical interlocking, thereby reducing manufacturing precision requirements without compromising shear load resistance.
3Object-affected harmful factors
If the panel uses vertically extending cavities through the core structure, then low-frequency noise attenuation is improved, but structural thickness increases
Solution Approach 1:
The core structure is segmented into multiple discrete units with cavities extending vertically through each segment. By dividing the core into multiple smaller structures connected by splice joints, the panel achieves the noise attenuation effectiveness of vertically extending cavities without requiring a single continuous thick core structure, thereby reducing overall panel thickness.
Solution Approach 2:
The noise attenuation function is achieved by extending cavities in the vertical dimension through the core structure segments. This vertical extension creates resonance chambers that effectively attenuate low-frequency noise without requiring increased thickness in the horizontal dimensions, allowing the panel to maintain a compact overall thickness while achieving superior noise attenuation performance.
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 panel effectively attenuates low-frequency noise without increasing thickness, utilizing resonance chambers and meshed protrusions for strong bonding and improved shear load resistance.
Implementation Method 1
The core may include a viscous material configured to attenuate sound waves passing through the core structure.
Implementation Method 2
The panel effectively attenuates low-frequency noise without increasing thickness, utilizing resonance chambers
Data Source
AI summary
A structural panel is provided that includes a first core structure and a second core structure. The first core structure is configured with a first endwall and a plurality of first cavities that extend vertically through the first core structure. The second core structure is configured with a second endwall and a plurality of second cavities that extend vertically through the second core structure. The second core structure is laterally bonded to the first core structure at a complex splice joint between the first endwall and the second endwall.