Cellular Acoustic Panel Rework Without Blocking Honeycomb Cells
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for reworking acoustic panels in aircraft engine assemblies, such as those with honeycomb cores, often result in blocked cells or reduced acoustic performance due to the use of foaming adhesives, which may not meet regulatory standards for noise reduction, necessitating costly part replacements.
Innovation Solution
A method involving a guide and cutting apparatus that allows for precise removal and replacement of cellular core sections within acoustic panels, using a guide with a base and legs to engage cell walls, and a cutting instrument to sever cell walls, enabling the insertion of a rework section plug with intact septums to maintain acoustic performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If foaming adhesives are used to secure reworked sections, then structural strength is restored, but acoustic performance deteriorates due to blocked honeycomb cells
Solution Approach 1:
The patent removes the problematic foaming adhesive from the rework process entirely. Instead, it uses mechanical insertion of a rework section into a precisely cut cavity in the honeycomb core, securing it with adhesive applied only to the mating surfaces of the rework section, not within the cells. This extracts the harmful element (foaming adhesive blocking cells) while maintaining the beneficial element (structural restoration).
Solution Approach 2:
The patent introduces a rework section as an intermediary component that bridges the damaged area. This rework section has a cavity that receives the removed portion, and its outer surface is bonded to the surrounding honeycomb core. The intermediary structure allows structural restoration without compromising the acoustic integrity of the remaining cells.
2Ease of repair
If acoustic panels are reworked to restore structural strength, then ease of repair is improved, but acoustic performance may be compromised, necessitating part replacement
Solution Approach 1:
The patent segments the repair process into distinct steps: removing the damaged section, preparing the cavity, inserting the rework section, and bonding. This segmentation allows for precise control of each step, ensuring that cells are not blocked during the process. The modular rework section can be manufactured separately and precisely fitted, maintaining acoustic performance while enabling repair.
Solution Approach 2:
The patent performs preliminary actions by precisely cutting the cavity to match the rework section dimensions before insertion. This preliminary precision work ensures that the rework section fits tightly without requiring forceful insertion that could damage cells. The preliminary preparation of bonding surfaces also ensures optimal adhesive bonding without compromising acoustic integrity.
3Stability of the object's composition
If honeycomb cells are blocked during rework, then structural integrity is improved, but acoustic performance deteriorates, increasing loss of substance
Solution Approach 1:
The patent applies local quality by concentrating the adhesive bonding only at the interface between the rework section and the surrounding honeycomb core, rather than filling the entire rework area with adhesive. This localized application of bonding material restores structural integrity at the repair location while leaving the acoustic cells open and functional. The rework section itself is designed with the same cellular structure as the original core, maintaining local acoustic properties.
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 restores structural strength and acoustic performance of reworked panels while allowing in-situ repairs, reducing the need for part replacements and maintaining compliance with noise regulations.
Implementation Method 1
the cavities in the core act as Helmholz resonators and attenuate the sound of the associated airflow
Implementation Method 2
core walls between adjacent cavities in the core act as acoustic septa to attenuate the sound of the airflow
Data Source
Figure 1A~2B
Figure 3~4
Figure 5~6
AI summary
Methods for reworking structures and reworked cellular core panels, reworked structures comprising the reworked cellular core panels, and guides and cutting apparatuses for reworking cellular acoustic panels and reworking cellular non-acoustic panels are disclosed. (Fig. 1A)