Shape Memory Alloy Tooling for Composite Contouring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The formation of contoured composite structures using fiber-reinforced materials is challenging due to the high cost of precise molds and the difficulty in avoiding wrinkles when conforming planar sheets to complex contours, which can result in performance issues in the final structure.
Innovation Solution
The use of shape memory alloys that deform when heated to conform composite materials to desired contours, allowing for the formation of complex shapes without the need for expensive molds and minimizing wrinkles, by positioning a sheet of composite material in relation to a shape memory alloy structure, heating it to its activated temperature range, and then cooling it to set the desired contour.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If expensive precise molds are used to form contoured composite structures, then manufacturing precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent uses a flexible membrane as a temporary copy or surrogate for the expensive rigid mold. The membrane is formed to match the desired contour and serves as a conforming surface during composite material forming. After the composite is formed, the membrane is removed, having served its purpose as a low-cost alternative to the permanent mold.
Solution Approach 2:
The flexible membrane is a disposable, low-cost component that is used temporarily during the forming process and then discarded. It replaces the expensive, reusable rigid mold by providing a single-use conforming surface that achieves the desired precision without the high cost and complexity of manufacturing a precise rigid mold.
2Shape
If planar composite sheets are conformed to complex contours, then desired shape is achieved, but wrinkles and anomalies are introduced
Solution Approach 1:
The flexible membrane is inflated to a controlled pressure that allows it to dynamically conform to the desired contour while maintaining surface quality. The pressure is adjusted to achieve the right balance between conforming to the complex shape and preventing wrinkles in the composite material.
Solution Approach 2:
The patent changes the physical state and properties of the membrane by controlling its temperature and pressure. Heating the membrane makes it more flexible and easier to conform, while controlled inflation pressure ensures it achieves the desired contour without creating wrinkles. These parameter changes allow the membrane to adapt to complex shapes while maintaining surface quality.
3Productivity
If large molds are constructed to form composite structures, then manufacturing capability is improved, but cost and maintenance requirements increase
Solution Approach 1:
Instead of constructing expensive large rigid molds, the patent uses inflatable flexible membranes that can be manufactured at low cost. These membranes are inflated to the required size and shape, providing the necessary manufacturing capability without the high cost and maintenance requirements of permanent large molds.
Solution Approach 2:
The inflatable membrane provides dynamic manufacturing capability - it can be inflated to the required size for large structures and deflated for storage or reconfiguration. This eliminates the need for permanent large-scale mold infrastructure, reducing both cost and maintenance requirements while maintaining full manufacturing capability when needed.
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 method enables the cost-effective formation of contoured composite structures with complex shapes, maintaining the desired contour without wrinkles, and allows for the creation of structures like aerospace components with improved performance.
Implementation Method 1
a structure of shape memory alloy configured to deform from a first conformation to a second conformation when heated to within an activated temperature range
Implementation Method 2
heating the structure of shape memory alloy to within the activated temperature range
Implementation Method 3
cooling the structure of shape memory alloy to below the activated temperature range
Data Source
Figure 1~2
Figure 3~5
Figure 6~8
AI summary
Methods and tools (100) for forming contoured composite structures (12) are disclosed. Methods include positioning a sheet of composite material (102) relative to a structure of shape memory alloy (104), heating the structure of shape memory alloy (104) to deform the structure of shape memory alloy (104) to a deformed conformation (108) and thereby conform the sheet of composite material (102) to a desired contour (110) corresponding to the deformed conformation (108) of the structure of shape memory alloy (104). Tools (100) include a structure of shape memory alloy (104) and a heat source (114) for heating the structure of shape memory alloy (104) to conform a sheet of composite material (102) to a desired contour (110) corresponding to the deformed conformation (108) of the structure of shape memory alloy (104).