Acoustic Fastening Element for Sandwich Panel Vibration Decoupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Sandwich panels used in aircraft cabins, known for their stiffness and lightness, often exhibit undesirable acoustic behavior due to structure-borne noise, which is not effectively mitigated by existing methods such as filling the core with pastes or applying damping materials.
Innovation Solution
A system comprising a support core composite panel with a fastening element featuring a sealing system with a permanently elastic elastomer or metal, designed to decouple vibrations, and a support core with a changing profile thickness and uneven surface to absorb or reflect vibrations, reducing structure-borne noise excitation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If sandwich panels are made stiff and lightweight with parallel top and bottom layers, then weight is optimized and structural strength is improved, but structure-borne noise is transmitted effectively and impact noise is perceived as too loud
Solution Approach 1:
The patent applies local quality by introducing non-parallel configurations only in specific areas where acoustic performance is needed, rather than changing the entire panel structure. The top and bottom layers are made non-parallel locally to create acoustic benefits while maintaining overall structural integrity and weight optimization.
Solution Approach 2:
The patent employs asymmetry by making the top and bottom layers non-parallel, creating an asymmetric geometry that disrupts the transmission path of structure-borne noise. This asymmetric configuration prevents effective coupling of vibrations while maintaining the lightweight characteristic of the sandwich panel.
2Object-generated harmful factors
If damping material is applied to the surface or core is filled with pastes and granules, then impact noise and structure-borne noise are damped, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent merges the structural function with the acoustic damping function by integrating the non-parallel layer configuration directly into the sandwich panel structure itself, rather than adding separate damping materials or components. This combination achieves noise reduction without increasing device complexity.
Solution Approach 2:
The sandwich panel structure serves dual purposes: it provides structural support while simultaneously damping structure-borne noise through its non-parallel configuration. The structure itself performs the acoustic function without requiring additional damping materials or complex assemblies.
3Object-generated harmful factors
If non-parallel top and bottom layers are used, then structure-borne noise transmission is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The patent applies segmentation by dividing the panel into discrete layers that can be manufactured and assembled separately. The non-parallel configuration is achieved through controlled positioning of these segmented layers, allowing for manageable manufacturing precision requirements while still achieving the desired acoustic 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 solution effectively reduces the transmission of vibrations in the audible range, improving the acoustic and mechanical properties of the composite panels by customizing their vibration behavior to dampen noise and ensure necessary force transmission.
Implementation Method 1
the sealing system is designed as a permanently elastic elastomer
Implementation Method 2
designed to decouple vibrations, and a support core with a changing profile thickness and uneven surface to absorb or reflect vibrations
Data Source
Figure 1~3
Figure 4
Figure 5
AI summary
A fastening element (17) for a support core composite panel (1) is specified, wherein the fastening element is designed to reduce or prevent structure-borne sound excitation, the fastening element (17) comprising: a first insert (21) with thread (22) and a second insert (21) with thread (22); a first sleeve (18) and a second sleeve (20); and a sealing system (19), wherein the first insert is screwed into the first sleeve and wherein the second insert is screwed into the second sleeve, wherein the first insert and the second insert are decoupled and force-fit into the sealing system (19).