Monolithic Composite Nacelle Mandrel Tooling
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Solution Overview
Problem
Current fan duct panel fabrication methods require multiple tools for each lofted surface, leading to increased costs, longer processing times, significant tool weight, structural inefficiencies, worker exhaustion, and material waste due to bulky and heavy tooling.
Innovation Solution
A multi-piece mandrel tool that combines inner and outer lofted surfaces, allowing for a single tool to form a continuous fan duct panel with reduced weight and deflection, using aluminum for thermal growth management and featuring efficient structural rigidity, enabling vertical placement and automated fairing bar placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple tools are allocated to each lofted surface, then each surface can be formed individually, but the tool count increases and multiple cure stages are required
Solution Approach 1:
The patent combines multiple discrete tools into a single integrated mandrel that forms both the inner and outer fan duct surfaces simultaneously. The mandrel includes an inner mandrel portion and an outer mandrel portion that work together as one unified tooling system, eliminating the need for separate tools for each lofted surface and reducing the number of cure stages required.
Solution Approach 2:
The single mandrel tool is designed to perform multiple functions: it forms both the inner and outer surfaces of the fan duct, provides structural support during curing, and enables monolithic panel fabrication. This multi-functional design replaces what previously required multiple specialized tools.
2Manufacturing precision
If known tooling is used, then fan duct surfaces can be formed, but the tool weight becomes significant and requires substantial capital equipment to move
Solution Approach 1:
The mandrel is divided into multiple separable sections including an inner mandrel portion and an outer mandrel portion that can be assembled and disassembled. This segmentation reduces the weight of individual components, making them easier to handle and move without requiring substantial capital equipment.
Solution Approach 2:
The patent changes the material parameters and structural configuration of the tooling to reduce weight while maintaining sufficient rigidity for precision forming. The segmented design allows for lighter materials to be used in each section while the overall assembly provides the necessary structural support.
3Manufacturing precision
If known tooling is designed for deflection compensation, then lofted contours can be replicated with tight tolerances, but the tools become bulky and require workers to bend and climb
Solution Approach 1:
The mandrel is designed with inherent structural rigidity that minimizes deflection during use, eliminating the need for bulky compensation mechanisms. The inner and outer mandrel portions are configured to work together as a stable framework that maintains precision without requiring workers to bend or climb over heavy structures.
4Ease of manufacture
If multiple fairing bars are used on known tooling, then part fabrication can proceed, but the number of individual components increases and labor time increases
Solution Approach 1:
The patent reduces the number of fairing bars from multiple individual components to just two main fairing bars that span the entire mandrel structure. These two fairing bars provide sufficient support for the vacuum bag and part fabrication process, dramatically reducing the time required for placement and removal compared to multiple smaller fairing bars.
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 reduces tool count and cure cycles, minimizes material waste, enhances worker safety, and simplifies fairing bar replacement, while accommodating various fan duct configurations and reducing labor and material costs.
Implementation Method 1
The ability to use aluminum in this application adds a further advantage to capture the effect of thermal growth of the tool relative to part materials.
Data Source
AI summary
A mandrel is disclosed for fabricating a monolithic composite nacelle panel for use on an airplane. Also disclosed is the method of constructing the mandrel, the method of assembling the mandrel, and the method of disassembling the mandrel.