Multi-Layer Joint Structure for Dissimilar Material Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The bonding between members made of different materials, such as fiber reinforced plastic and metallic materials, experiences a decrease in strength due to cracks generated by differences in deformation, leading to reduced fatigue strength in joint structures, particularly in aircraft components.
Innovation Solution
A joint structure is designed with a fit-in groove and an insertion section, featuring multiple bonding layers of varying hardness between the groove and the insertion section, where softer layers are strategically placed to absorb deformation and harder layers provide strength, and fiber-containing layers are oriented to optimize tensile load resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If members made of different materials (fiber reinforced plastic and metallic materials) are bonded together, then the joint structure can achieve material diversity and design flexibility, but the bonding strength decreases due to cracks generated by differences in deformation
Solution Approach 1:
The patent applies local quality by creating bonding layers with different hardness values at different locations within the bonding interface. Specifically, a first bonding layer with hardness of 20-40 JIS and a second bonding layer with hardness of 40-60 JIS are used in combination, allowing different regions to have different mechanical properties optimized for their specific functions - softer regions for stress absorption and harder regions for structural strength
Solution Approach 2:
The patent employs composite materials by combining multiple bonding layers with different hardness characteristics between the fiber reinforced plastic member and metallic member. This multi-layer bonding structure integrates materials with complementary properties to simultaneously achieve flexibility for deformation accommodation and rigidity for load bearing, resolving the contradiction between material adaptability and bonding strength
2Device complexity
If a single bonding layer is used between different material members, then the structure is simple, but cracks occur due to deformation differences reducing fatigue strength
Solution Approach 1:
The patent applies segmentation by dividing the bonding interface into multiple discrete bonding layers with different hardness values. Instead of using a single uniform bonding layer, the structure is segmented into a first bonding layer (hardness 20-40 JIS) and a second bonding layer (hardness 40-60 JIS), where each segment performs a specific function in crack prevention and load distribution, thereby improving fatigue strength
Solution Approach 2:
The patent utilizes parameter changes by varying the hardness parameter of bonding layers at different positions. The first bonding layer has hardness of 20-40 JIS while the second bonding layer has hardness of 40-60 JIS. This parameter variation allows the bonding structure to accommodate deformation differences between dissimilar materials while maintaining overall structural integrity and fatigue resistance
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A joint structure (100) includes a first member (110) having a fit-in groove (116), a second member (120) made of a material different from a material of the first member (110) and having an insertion section (124) to be inserted into the fit-in groove (116), and a plurality of bonding layers having different hardness and formed between the fit-in groove (116) and the insertion section (124).