Composite Wiper Arm with Metal Layer for Lightning Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aircraft windshield wiper systems made from composite materials lack the electrical conductivity needed to dissipate lightning strike energy, failing to meet FAA lightning strike requirements, while traditional metal wiper arms are heavy and inefficient.
Innovation Solution
A windshield wiper system with a composite shaft surrounded by a metal layer and coupled with metallic channels and shafts, creating a conductive path to dissipate electrical surges safely, combining the strength and reduced weight of composite materials with the conductivity needed for lightning protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If composite materials are used for the wiper arm, then weight is reduced and structural performance is improved, but electrical conductivity is insufficient to meet FAA lightning strike requirements
Solution Approach 1:
The wiper arm employs a hybrid composite structure combining non-conductive composite materials (for weight reduction and strength) with conductive metal components (for lightning strike protection). The composite shaft is surrounded by a metal layer and coupled with metallic channels, creating a hybrid material system that simultaneously achieves weight reduction and electrical conductivity for FAA compliance.
Solution Approach 2:
The wiper arm structure implements local quality by applying conductive metal layers and channels specifically at strategic locations (surrounding the composite shaft and at coupling points) rather than making the entire structure metallic. This allows the majority of the wiper arm to remain lightweight composite while specific regions provide the necessary electrical conductivity for lightning protection.
2Reliability
If metal is used for the wiper arm, then lightning strike requirements are met, but weight increases and aircraft efficiency decreases
Solution Approach 1:
The wiper arm implements local quality by applying conductive metal layers and channels specifically at strategic locations (surrounding the composite shaft and at coupling points) rather than making the entire structure metallic. This allows the majority of the wiper arm to remain lightweight composite while specific regions provide the necessary electrical conductivity for lightning protection.
Solution Approach 2:
The wiper arm employs a hybrid composite structure combining non-conductive composite materials (for weight reduction and strength) with conductive metal components (for lightning strike protection). The composite shaft is surrounded by a metal layer and coupled with metallic channels, creating a hybrid material system that simultaneously achieves weight reduction and electrical conductivity for FAA compliance.
3Reliability
If a metal layer surrounds the composite shaft, then electrical conductivity is improved for lightning protection, but device complexity increases
Solution Approach 1:
The wiper arm structure applies the nesting principle by placing the metal layer concentrically surrounding the composite shaft, with metallic channels nested at the ends. This nested arrangement integrates multiple functional layers (composite core for strength/weight, metal layer for conductivity) in a compact, organized manner that manages complexity through hierarchical structuring.
Solution Approach 2:
The wiper arm employs a hybrid composite structure combining non-conductive composite materials (for weight reduction and strength) with conductive metal components (for lightning strike protection). The composite shaft is surrounded by a metal layer and coupled with metallic channels, creating a hybrid material system that simultaneously achieves weight reduction and electrical conductivity for FAA compliance.
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 system effectively dissipates lightning strikes, ensuring the wiper arm's integrity and meeting FAA requirements while reducing aircraft weight and improving efficiency.
Implementation Method 1
The metal wiper arms have acceptable electrical resistance characteristics, providing an electric current flow path to an aircraft grounding surface where the energy surge due to the lightning strike is dissipated.
Data Source
Figure 1A
Figure 1B
Figure 1C
AI summary
An aircraft windshield wiper system (10) includes a wiper arm (14), a wiper blade (16) coupled to a distal end of the wiper arm, and a drive shaft (18) coupled to a proximal end of the wiper arm. The wiper blade (16) is configured to clean water, dirt, and other debris from the windshield of the aircraft. The drive shaft (18) is configured to rotate and cause the wiper arm with the coupled wiper blade to sweep across the windshield. The wiper arm (14) includes both composite and metal components to reduce the weight of the windshield wiper system while also providing lightning strike protection.