Acoustic Panel Repair With Matched Perforation Alignment

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Solution Overview

Problem

Existing repair methods for acoustic panels in aircraft nacelles often result in diminished acoustic properties due to misaligned perforations between the replacement patch and the existing top skin, leading to suboptimal noise attenuation.

Innovation Solution

A method involving scanning the perforation pattern of the damaged acoustic panel using a camera system, storing the pattern, and using a computer numeric control machine to drill matching perforations in a replacement patch, ensuring alignment and proper bonding to maintain acoustic integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If existing repair techniques use a patch that overlaps the damaged top skin, then the structural integrity is restored, but the acoustic properties are diminished due to misaligned perforations

Engineering Contradiction:

Improvestructural integrityVSAvoidacoustic properties

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The patent applies preliminary action by scanning and storing the perforation pattern of the damaged top skin before removing it, then using this stored pattern to guide the drilling of perforations in the replacement patch. This ensures that the perforations are pre-planned to align perfectly with the existing pattern, maintaining acoustic properties while restoring structural integrity.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses copying by creating a digital replica of the original perforation pattern through scanning, storing it in computer memory, and then using this copied pattern to guide the drilling process. This allows the replacement patch to replicate the exact perforation arrangement of the original top skin, ensuring acoustic property preservation.

Inventive Principle:

Principle #26Copying

2Ease of manufacture

If manual repair methods are used to replace the damaged top skin, then the repair process is simple, but the alignment precision of perforations deteriorates

Engineering Contradiction:

Improverepair process simplicityVSAvoidperforation alignment

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent replaces manual mechanical alignment methods with an automated computer-controlled drilling system. The CNC drill uses the stored perforation pattern to automatically position and drill holes with high precision, eliminating the need for manual measurement and alignment while maintaining repair process efficiency.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements feedback by scanning the actual perforation pattern of the damaged top skin, storing it digitally, and using this information to control the drilling process. The system continuously references the stored pattern during drilling to ensure each perforation is placed at the correct location, providing real-time guidance for precise alignment.

Inventive Principle:

Principle #23Feedback

Data Source

PatentEP3558650B1Machine vision acoustic panel repair with retention of acoustic properties

Publication Date: 2022.05.04 ROHR INC

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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.