Aircraft Acoustic Panel Patch Repair With Matched Perforations
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing repair techniques for acoustic panels in aircraft nacelle structures often diminish the acoustic properties due to misaligned perforations between replacement patches and the existing top skin, leading to undesirable voids or delamination.
Innovation Solution
A method involving scanning the perforation pattern of a damaged acoustic panel using a camera system, storing it in a computer, and using a CNC machine with a six-axis system to drill matching perforations in a replacement patch, which is then bonded to the panel, ensuring alignment and retention of acoustic properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If existing repair techniques use overlapping patches without aligned perforations, then the repair process is simple, but the acoustic properties are diminished
Solution Approach 1:
The patent applies preliminary action by scanning and storing the perforation pattern of the damaged top skin before removing it. This stored pattern is then used to guide the CNC machine in drilling accurately positioned perforations in the replacement patch, ensuring alignment with the underlying core and maintaining acoustic properties while keeping the repair process systematic and manageable
Solution Approach 2:
The patent uses copying by creating a digital replica of the original perforation pattern through camera scanning and image processing. This copied pattern is then transferred to the replacement patch via CNC drilling, ensuring that the new patch replicates the acoustic characteristics of the original panel without requiring manual measurement or estimation
2Device complexity
If perforations are drilled manually in replacement patches, then the equipment required is simple, but the alignment precision with existing top skin is poor
Solution Approach 1:
The patent replaces manual mechanical drilling with a CNC (computer numerical control) machine that uses digital coordinates derived from scanned images. This substitution of mechanical estimation with computer-controlled precision positioning enables accurate perforation alignment while maintaining reasonable equipment complexity through the use of standard CNC technology
Solution Approach 2:
The patent implements feedback by using camera scanning to capture the actual perforation pattern, processing this visual information into coordinate data, and using these coordinates to control the CNC drilling process. This closed-loop approach ensures that the drilled perforations accurately match the original pattern and align with the underlying core structure
3Ease of repair
If the top skin is removed and replaced with a patch, then damaged portions can be repaired, but voids or delamination may occur in the overlap area
Solution Approach 1:
The patent applies preliminary action by precisely positioning and drilling perforations in the replacement patch before bonding it to the core. This pre-alignment ensures that when the patch is bonded, the perforations match the underlying core structure, preventing voids and delamination in the overlap area while maintaining panel integrity
Solution Approach 2:
The patent uses air blowing through the perforations to self-remove excess adhesive from the perforation areas. This self-cleaning action prevents adhesive buildup that could cause voids or delamination, while the precise perforation alignment ensures proper bonding between the replacement patch and the core structure
Data Source
AI summary
An acoustic panel (200) for an aircraft nacelle (100) may comprise a perforated first skin (220), a second skin (230), and a core (210) sandwiched between them. A camera system (330) may scan a perforation pattern of a damaged portion (311) of the perforated first skin (220). The damaged portion (311) of the perforated first skin (220) may be removed. A replacement patch (660) may be formed. A CNC machine (450) may drill the replacement patch (660) according to the perforation pattern. The perforations (425) in the replacement patch (660) may be aligned with perforations (325) in the perforated first skin.