Reformable Mandrel With Shape-Memory Core for Wrinkle-Free Composite Layup
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing mandrel technologies for composite materials face challenges in shaping complex or contoured structures, leading to wrinkles and high inspection costs, or require costly and time-intensive custom rigid mandrels.
Innovation Solution
A reformable mandrel system using a core with a transitional state material and a heat-resistant sleeve, allowing the core to transition from rigid to flexible states at defined temperatures, enabling easy shaping and non-destructive removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If composite materials are placed on a flexible mandrel and draped on a curved mold, then complex or contoured shapes can be formed, but wrinkles, defects, and high inspection costs occur
Solution Approach 1:
The mandrel uses a shape memory polymer core that can dynamically change its rigidity state between rigid and flexible conditions. When heated above the transition temperature, the core becomes flexible to allow draping; when cooled below the transition temperature, it becomes rigid to maintain shape and support the composite part, eliminating wrinkles and defects
Solution Approach 2:
The mandrel's physical state is changed by controlling temperature parameters. By heating the mandrel above the transition temperature of the shape memory polymer, it transitions from a rigid state to a flexible state for draping operations. By cooling it below the transition temperature, it returns to a rigid state to provide dimensional stability and support, thus preventing wrinkles and defects
2Shape
If specifically contoured rigid mandrels are created for each layup design, then complex shapes can be formed, but costs and time increase
Solution Approach 1:
The shape memory polymer core allows the mandrel to be dynamically reconfigured between rigid and flexible states through temperature control. This enables a single mandrel to adapt to different contoured shapes by heating above the transition temperature for shaping, then cooling to maintain the new shape, eliminating the need for multiple custom rigid mandrels and reducing production time
Solution Approach 2:
By changing the temperature parameter of the shape memory polymer core, the mandrel can transition between different rigidity states and conform to different contoured shapes. This parameter-based control allows one mandrel to replace multiple custom-designed rigid mandrels, significantly reducing both costs and time for creating new layup designs
3Stability of the object's composition
If a rigid mandrel is used to support uncured composite part, then shape stability is maintained, but removal becomes difficult without damage
Solution Approach 1:
The shape memory polymer core provides dynamic rigidity control: when cooled below the transition temperature, it maintains a rigid state to support the uncured composite part and ensure shape stability; when heated above the transition temperature, it becomes flexible to allow easy removal of the mandrel without damaging the cured composite part, enabling non-destructive extraction
4Ease of operation
If the mandrel material transitions from rigid to flexible state, then shaping and removal become easier, but structural support during curing may be compromised
Solution Approach 1:
The shape memory polymer core's transition temperature is carefully selected to be lower than the composite curing temperature. During curing, the mandrel is maintained below the transition temperature to remain rigid and provide structural support. After curing, the mandrel is heated above the transition temperature to become flexible for easy removal, thus maintaining both structural support during curing and ease of removal afterward
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
Facilitates the formation of complex composite parts without wrinkles, reduces costs, and allows for reusable mandrel use by maintaining shape and supporting uncured composite parts during curing.
Implementation Method 1
a core (110) including a transitional state material having a transition temperature, and wherein the core is configured to maintain a rigid state below the transition temperature and a flexible state above the transition temperature
Data Source
AI summary
A method for making a composite part using a reformable mandrel, including contouring a reformable mandrel; placing an uncured composite part on the reformable mandrel; curing the uncured composite part; and removing the reformable mandrel, wherein the reformable mandrel includes a core including a transitional state material having a transition temperature, and a sleeve at least partially surrounding the core and including a heat-resistant flexible material having an operational temperature.