Flexible Bladder Mandrel for Composite Reinforcement Structures
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The manufacturing of reinforcement structures, such as those used in aircraft and automotive vehicles, is time-consuming and costly due to the use of metal fixing devices, which also add weight and do not provide the highest strength-to-weight ratio, while fiber-reinforced composite materials offer better performance.
Innovation Solution
The use of a flexible bladder surrounding a rigid mandrel to support a reinforcement structure-forming material, applying a force through a pressure differential to compact and densify the material, eliminating the need for metal fasteners and enabling the formation of a lightweight, high-strength fiber-reinforced composite structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If metal fixing devices are used to attach internal features to outer skin, then the reinforcement structure achieves sufficient mechanical strength, but the manufacturing time and cost increase significantly
Solution Approach 1:
The patent merges the internal features and outer skin into a single integrally formed composite structure. The reinforcement structure is manufactured as one piece using fiber-reinforced composite materials molded around mandrels, eliminating the need for separate attachment operations with metal fasteners. This integration directly resolves the contradiction by achieving both mechanical strength through material design and reduced manufacturing time through single-step formation.
Solution Approach 2:
The patent employs fiber-reinforced composite materials (such as carbon fiber, glass fiber, or aramid fiber reinforced polymers) to achieve high mechanical strength without requiring metal fixing devices. The composite material itself provides the necessary strength and stiffness, while the molding process integrates all components into a unified structure, thereby eliminating time-consuming assembly operations.
2Strength
If metal fixing devices are used to attach internal features, then the reinforcement structure achieves adequate strength, but the overall weight of the structure increases
Solution Approach 1:
The patent uses fiber-reinforced composite materials that provide high strength-to-weight ratio, exceeding that of traditional metal structures. The integral formation eliminates metal fasteners and reduces the need for additional structural reinforcement, resulting in a lighter overall structure while maintaining or enhancing mechanical strength.
Solution Approach 2:
The patent extracts and eliminates metal fixing devices from the reinforcement structure. By transitioning to an integrally formed composite structure, all metal fasteners, rivets, and associated hardware are removed, significantly reducing the overall weight while the composite material compensates for the lost mechanical connection through its inherent strength properties.
3Strength
If traditional manufacturing methods with metal fasteners are used, then the reinforcement structure achieves necessary mechanical properties, but the manufacturing cost increases
Solution Approach 1:
The patent combines multiple manufacturing operations into a single molding process. The integral formation of the reinforcement structure eliminates sequential steps such as separate component fabrication, positioning, fastener installation, and quality inspection of joints. This consolidation reduces labor hours, material waste, and manufacturing complexity, directly lowering production costs while maintaining structural integrity.
Solution Approach 2:
The patent replaces the mechanical fastening system (metal fasteners, rivets, bolts) with a chemical bonding system through composite material curing. The resin matrix bonds the fiber reinforcement and internal features together during the molding and curing process, eliminating the need for mechanical assembly operations and associated tooling, labor, and quality control requirements.
4Weight of moving object
If fiber-reinforced composite materials are used instead of metal, then the strength-to-weight ratio improves, but new manufacturing challenges arise
Solution Approach 1:
The patent applies preliminary action by pre-forming the fiber-reinforced composite material into the desired reinforcement structure shape using mandrels before final curing. The mandrels provide the necessary form and structural definition during material placement and curing, simplifying the overall manufacturing process despite the complexity of working with composite materials. This pre-forming approach eliminates the need for complex post-processing and assembly operations.
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 reduces manufacturing time and costs, produces a lightweight yet strong reinforcement structure without metal fasteners, and ensures accurate shaping and bonding of internal features to the outer skin, enhancing mechanical properties.
Implementation Method 1
The first flexible bladder is configured to apply a force to the reinforcement structure-forming material in a direction opposite the first rigid mandrel in response to a pressure differential between inside and outside of the first flexible bladder
Implementation Method 2
A vacuum condition is produced outside of the first and second flexible bladders such that the first and second flexible bladders compress the reinforcement structure-forming material to facilitate forming an internal feature of the reinforcement structure
Data Source
AI summary
Apparatuses and methods for making reinforcement structures are provided. In one example, an apparatus for making a reinforcement structure includes a rigid mandrel and a flexible bladder. The flexible bladder at least partially surrounds the rigid mandrel for supporting a reinforcement structure-forming material during fabrication of the reinforcement structure. The flexible bladder is configured to apply a force to the reinforcement structure-forming material in a direction opposite the rigid mandrel in response to a pressure differential between inside and outside of the flexible bladder.