Embedding Fasteners in 3D Microstructure Cores
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for embedding fasteners in sandwich structures with closed-cell cores damage the core, are time-consuming, and inefficient in transmitting mechanical loads, and pose challenges in sealing to prevent fluid ingress and corrosion, especially in multi-function applications.
Innovation Solution
A method involving attaching fasteners to one facesheet, irradiating a photo-monomer with light to form an ordered three-dimensional microstructure core around the fasteners, and attaching the second facesheet, which allows for efficient mechanical load transmission and sealing without core damage, using a process that creates a lightweight yet strong open cellular core.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If holes are drilled through the core to embed fasteners, then fasteners can be installed to connect the sandwich structure, but the core material is damaged and structural integrity is compromised
Solution Approach 1:
The core is formed with pre-defined cavities and channels during the manufacturing process before fastener installation. These cavities are precisely positioned to receive fasteners without requiring post-manufacturing drilling or machining operations, thereby avoiding damage to the core material while enabling fastener installation.
Solution Approach 2:
The invention replaces the mechanical drilling process with a chemical/thermal forming process during core manufacturing. Instead of mechanically removing material to create fastener holes, the core is formed with integrated cavities through molding or additive manufacturing processes, eliminating the harmful mechanical drilling action.
2Weight of moving object
If conventional core materials are used, then the sandwich structure maintains lightweight properties, but the core compression strength is insufficient to support high fastener torque
Solution Approach 1:
The core structure features localized reinforcement around fastener installation points and load-bearing regions. The cellular geometry is optimized with denser or stronger material distribution in areas subjected to high compression forces from fastener torque, while maintaining lightweight cellular structure in non-critical areas to minimize overall weight.
Solution Approach 2:
The core utilizes composite material construction combining lightweight cellular material with strategic reinforcement elements. The core may incorporate hybrid structures such as foam with embedded fibers, or cellular metal with strategic alloying, providing enhanced compression strength at fastener locations while preserving the overall lightweight characteristic of the sandwich structure.
3Ease of manufacture
If fastener holes are created in the facesheets, then fasteners can be installed, but fluid leak paths are created that allow fluid ingress into the core
Solution Approach 1:
The invention introduces sealing elements as intermediary components between the fastener and the core/facesheet interface. These seals may include gaskets, O-rings, or integrated sealing lips that prevent fluid leakage through the fastener penetration points, thereby blocking the harmful fluid ingress pathway while allowing fastener installation to proceed.
Solution Approach 2:
The core structure incorporates flexible sealing membranes or thin film barriers that conform to the fastener interface and prevent fluid penetration. These flexible sealing layers can accommodate fastener installation while maintaining fluid tightness, preventing corrosive fluids from reaching the core material.
4Ease of manufacture
If conventional embedding methods are used, then fasteners can be installed, but the process is time-consuming and costly
Solution Approach 1:
The core is manufactured with pre-formed cavities, channels, and mounting features integrated into the core structure during the primary manufacturing process. This preliminary preparation eliminates the need for separate drilling, tapping, or fastener installation operations, significantly reducing manufacturing steps and improving productivity while maintaining ease of fastener embedding.
Solution Approach 2:
The invention merges the core manufacturing process with the fastener embedding process into a single integrated operation. Fastener cavities and mounting features are formed simultaneously with the core structure through molding or additive manufacturing, combining what would traditionally be separate manufacturing steps into one efficient process, thereby reducing time and cost.
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
Enables efficient embedding of fasteners that can transmit mechanical loads effectively while maintaining core integrity, reducing the risk of fluid ingress and corrosion, and allowing for multi-functionality in sandwich structures.
Implementation Method 1
irradiating a volume of photo-monomer in a reservoir with light beams to form an ordered three-dimensional microstructure core around the at least one fastener
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
Methods of embedding at least one fastener in a sandwich structure having an ordered three-dimensional microstructure core provided between a pair of facesheets. The method includes attaching the at least one fastener to a first facesheet. The method also includes irradiating a volume of photo-monomer in a reservoir with light beams to form an ordered three-dimensional microstructure core around the at least one fastener. The method also includes attaching a second facesheet to the ordered three-dimensional microstructure core to form the sandwich structure. The fasteners embedded in the sandwich structure are configured to facilitate attachment of the sandwich structure to another structure.