Composite Structure with Cross-Directional Fibers for Bonding
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Solution Overview
Problem
Composite structures made of metallic and fiber-reinforced plastic face issues with strain and delamination due to differences in thermal expansion coefficients between the two materials, leading to anisotropic expansion and shrinkage.
Innovation Solution
A laminated composite structure with uni-directional and cross-directional fiber-reinforced plastic reinforcement parts, including thermosetting resin, is used to create a bonding site between a metallic base member and the reinforcement parts, ensuring isotropic expansion and shrinkage, thereby reducing strain and delamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If fiber reinforced plastic with uni-directional reinforcement is used, then fiber reinforcement properties are obtained in the orientation direction, but anisotropic expansion and shrinkage occurs causing strain or delamination at the bonding site
Solution Approach 1:
The fiber reinforced plastic is divided into multiple layers with different fiber orientation directions. The first layer has fibers aligned in the longitudinal direction for strength, while the second layer has fibers aligned in the transverse direction to counteract anisotropic thermal expansion, thereby segmenting the reinforcement function across different orientations.
Solution Approach 2:
Different regions of the fiber reinforced plastic are given different fiber orientations tailored to local stress and thermal expansion requirements. The longitudinal layer provides strength along the main axis while the transverse layer provides dimensional stability perpendicular to the main axis, creating local quality variations to address specific directional needs.
2Strength
If metallic material and fiber reinforced plastic are bonded together, then composite structure is formed, but difference in thermal expansion coefficient causes strain or delamination at the bonding site
Solution Approach 1:
The invention uses a composite of metallic material and fiber reinforced plastic where the fiber orientation is specifically designed to match the thermal expansion characteristics of the metal substrate. By aligning some fibers in the transverse direction, the composite's effective thermal expansion coefficient is reduced to better match the metal, minimizing differential expansion stress at the bonding interface.
Solution Approach 2:
The thermal expansion coefficient of the fiber reinforced plastic is modified by changing the fiber orientation parameters. Introducing transverse fibers changes the effective thermal expansion behavior of the composite material, making it more compatible with the metallic material it is bonded to, thereby reducing thermal stress at the bonding site.
3Strength
If additional adhesives or surface treatments are used to improve bonding, then bonding strength is increased, but manufacturing process complexity and cost increase
Solution Approach 1:
The fiber reinforced plastic structure itself provides the bonding function through its thermosetting resin matrix, eliminating the need for separate adhesive applications. The resin cures to form a strong bond between layers and to the metal substrate, making the bonding process self-contained within the composite structure fabrication rather than requiring additional bonding steps.
Solution Approach 2:
The bonding function is merged with the structural reinforcement function. The same fiber reinforced plastic layers that provide mechanical strength also serve as the bonding medium through their thermosetting resin, combining structural and adhesive functions into a single integrated component rather than requiring separate bonding 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
The solution effectively suppresses strain and delamination at the bonding site while maintaining fiber reinforcement properties, allowing for a simpler manufacturing process and reduced product costs by eliminating the need for additional adhesives or surface treatments.
Implementation Method 1
a thermosetting resin included in a bonding site with the base member(s)
Implementation Method 2
there is a difference in an amount of thermal expansion or cooling shrinkage between in an orientation direction of reinforcement fibers
Implementation Method 3
the anisotropy of the expansion or shrinkage is generated depending on the orientation direction
Data Source
AI summary
A composite structure having a laminated structure made of fiber reinforced plastic and metallic material comprises a base member(s) made of metallic material; and a reinforcement member(s) made of fiber reinforced plastic, the reinforcement member(s) comprising: a first reinforcement part(s) made of fiber reinforced plastic including reinforcement fibers which are aligned in a uni-direction, and a second reinforcement part(s) made of fiber reinforced plastic including at least reinforcement fibers which are aligned in a crossing direction relative to the uni-direction in which the reinforcement fibers of the first reinforcement part(s) are aligned, and interposed between the base member(s) and the first reinforcement part(s), the reinforcement member(s) further comprising a thermosetting resin included in a bonding site with the base member(s).