Aircraft Wing Reinforcing Member Crack Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The difference in linear expansion coefficients between stiffener bodies and fillers made of fiber-reinforced plastic in aircraft wings leads to internal stress and crack generation during curing, affecting the yield of the assembly process.
Innovation Solution
A method involving the use of a crack regulating member to cover the end portion of the filler, reducing the likelihood of crack generation by aligning the fiber direction of the stiffener body and filler, and optionally forming a permissible crack or using a development prevention portion to prevent crack development.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the fiber direction of the stiffener body and filler are made different to achieve proper reinforcement, then the reinforcement effectiveness is improved, but internal stress and crack generation occur during curing
Solution Approach 1:
The patent applies local quality by making the fiber direction of the filler different from that of the stiffener body. Specifically, the filler is formed with fibers extending in a direction different from the stiffener body's fiber direction, allowing each component to be optimized for its specific function while managing the resulting thermal expansion differences through controlled design
Solution Approach 2:
The patent introduces a crack regulating member as an intermediary element between the stiffener body and filler. This crack regulating member acts as a mediator that manages the stress concentration at the interface between the two components with different fiber directions, preventing crack propagation while maintaining the benefits of differentiated fiber orientations
2Stability of the object's composition
If the filler is filled into the filler space to complete the reinforcing member, then the structural completeness is improved, but internal stress concentration and crack generation occur at the end portion
Solution Approach 1:
The crack regulating member serves as an intermediary element positioned between the filler and the stiffener body. It mediates the stress concentration that occurs at the interface between these two components, distributing stresses more evenly and preventing crack initiation and propagation at the end portion of the filler
Solution Approach 2:
The crack regulating member is installed beforehand to cushion or mitigate the stress concentration that will occur during the curing process. By placing this stress-managing element in advance, the patent prevents harmful stress concentration and crack generation before they can occur during assembly and curing
3Strength
If the reinforcing member is assembled to the skin panel to cure the skin panel, then the structural integrity is improved, but quality standards are not met due to crack generation
Solution Approach 1:
The crack regulating member acts as an intermediary protective element during the assembly and curing process. It mediates the thermal and mechanical stresses that occur when the reinforcing member is assembled to the skin panel, preventing crack generation that would otherwise cause rejection of the assembly and ensure compliance with quality standards
Solution Approach 2:
The crack regulating member is installed beforehand to cushion against the stress concentration and thermal expansion differences that occur during the curing process. This preventive measure ensures that the structural integrity achieved during assembly is maintained throughout curing, meeting quality standards by preventing crack formation
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 approach improves the yield of the assembly process by minimizing crack formation and ensuring quality standards are met, enhancing the structural integrity of aircraft wings.
Implementation Method 1
a difference in linear expansion coefficient between the stiffener body and the filler in a certain direction occurs. That is, a difference in the amount of thermal expansion or the amount of shrinkage between the reinforcing member body and the filler occurs
Data Source
AI summary
The method for producing an assembly is a method for producing an assembly equipped with a member to be reinforced (20), a reinforcing member body (41), and a filler (42), wherein the reinforcing member body (41) has a pair of flanges (44) arranged spaced on the surface (20B) of the member to be reinforced (20), a web (45), and a connection portion (46) which connects the flanges (44) and the web (45) and forms a filler space (V) with the surface (20B). The method for producing an assembly includes a step for inserting a filler (42) into the filler space (V), a step for attaching a crack control member (43) to cover the end of the filler (42), a step for joining the flanges (44) and the member to be reinforced (20), and a step for curing at least the member to be reinforced (20).