CFRP Housing Structure for Crack-Resistant Sharp Corners
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Carbon fiber reinforced plastic (CFRP) housings are prone to cracking and structural defects due to the alignment of carbon fibers, which limits their application in electronic devices with sharp corners or compound curves, and they lack durability and resistance to mechanical stresses.
Innovation Solution
A housing design featuring a CFRP spine and skin with layers of carbon fibers oriented in different directions, combined with a stair-step pattern and tapered segments, which distributes mechanical stresses and enhances bonding between the frame and skin, reducing the likelihood of cracking and separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If CFRP is used to provide high strength to weight ratio, then weight is reduced and strength is improved, but the material becomes prone to cracking under stress and bending
Solution Approach 1:
The housing is divided into multiple CFRP layers with carbon fibers oriented in different directions. This segmentation allows each layer to resist stress in its specific fiber orientation, preventing crack propagation through the entire structure while maintaining high strength to weight ratio.
Solution Approach 2:
The patent uses composite CFRP construction with multiple layers of different fiber orientations. This composite approach combines the high strength-to-weight advantage of CFRP with improved crack resistance through the layered structure, where each layer compensates for the limitations of the others.
2Ease of manufacture
If CFRP fibers are aligned in the same direction within each layer, then manufacturing is simplified, but the material cannot conform to sharp corners and compound curves
Solution Approach 1:
The housing structure is segmented into multiple CFRP layers, each with fibers aligned in different directions. This allows the structure to conform to sharp corners and compound curves while maintaining manufacturing simplicity for each individual layer.
Solution Approach 2:
The patent introduces a dimensional approach by stacking layers with different fiber orientations. This multi-dimensional arrangement enables the material to navigate complex geometries and sharp corners that would be impossible with single-direction fiber alignment.
3Device complexity
If the housing uses sharp corners and straight lines, then manufacturing is easier and structure is simpler, but stress concentrates at corners causing cracks
Solution Approach 1:
The patent applies different properties to different parts of the housing structure. At corner regions, the multi-layer CFRP construction with varying fiber orientations provides enhanced stress distribution and crack resistance, while maintaining simple straight-line geometries in other areas.
Solution Approach 2:
The use of composite CFRP layers with different fiber orientations creates a material structure that can handle stress concentrations at corners. The layered composite construction distributes stress more evenly compared to single-material constructions, improving reliability without significantly increasing overall structural complexity.
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 design provides enhanced structural integrity and resistance to cracking, allowing for the use of CFRP in applications with sharp corners and compound curves, while maintaining a strong and durable electronic housing.
Implementation Method 1
a housing formed from a carbon fiber reinforced plastic (CFRP)... The carbon fibers impart structural strength and resistance to bending and breaking against force applied transversely to the length of the fibers
Implementation Method 2
CFRP materials generally have a high strength to weight ratio and weight to stiffness ratio
Implementation Method 3
the two components may robustly bond to one another and have similar, if not identical, coefficients of thermal expansion. The combination of the robust bond and similar thermal expansion coefficient may permit the embodiment to resist cracking
Data Source
AI summary
A housing for an electronic device or other object formed from a fiber-in-matrix material. A layered fiber-in-matrix type material, such as CFRP, may be used. A spine made from CFRP may support, and be attached to, a CFRP skin. The CFRP spine may be a unitary frame that imparts strength and rigidity to the overall housing and also form at least some of the corners of the frame. In some embodiments, the spine may be rectangular. The skin may be formed from multiple layers of CFRP type material stacked atop each other. Each layer may be cut at one or more corners to expose at least a portion of the layer beneath. The skin may thus have an overall cross shape, such that each arm of the cross may be wrapped around a different side of the aforementioned rectangular spine.