Aircraft Wing Upper Joint Centroid Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The integration of aluminum alloys and composite materials in aircraft wing assemblies poses challenges due to incompatibilities in corrosion and thermal expansion, making it difficult to effectively transfer loads between sections constructed of different materials.
Innovation Solution
The design of an upper joint assembly that includes an outboard and center upper wing panel, rib, and flanges, with strategically configured stringers and compression fittings to align centroids of compressive pressures, using materials like titanium alloys for the joint assembly to accommodate different thermal expansion coefficients and galvanic properties of the wing panels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If aluminum alloys and composite materials are used for different wing sections, then weight reduction and strength-to-weight ratio are improved, but corrosion compatibility and thermal expansion compatibility deteriorate
Solution Approach 1:
The patent introduces an intermediate joint assembly containing dissimilar metal fasteners (e.g., aluminum-to-titanium or aluminum-to-steel) that act as a mediator between aluminum alloy wing boxes and composite wing center sections. This intermediary layer prevents direct contact between incompatible materials, thereby preventing galvanic corrosion while enabling load transfer between the different material sections.
Solution Approach 2:
The patent utilizes composite materials (fiber-reinforced polymers) for the wing center section and aluminum alloys for the outboard wing boxes, combining the advantages of both material systems. The composite sections provide high strength-to-weight ratio and corrosion resistance, while the aluminum sections provide ease of manufacturing and structural rigidity, creating a hybrid structure that optimizes overall performance.
2Weight of moving object
If aluminum alloys and composite materials are used for different wing sections, then weight reduction and strength-to-weight ratio are improved, but thermal expansion compatibility deteriorates
Solution Approach 1:
The joint assembly serves as a thermal buffer zone with fasteners and bonding structures that accommodate differential thermal expansion between aluminum and composite materials. The intermediate materials and joint design allow each section to expand and contract at its own rate without creating excessive stresses at the interface.
Solution Approach 2:
The patent employs joint design parameters (fastener spacing, bonding layer thickness, material selection) that are specifically optimized to accommodate thermal expansion differences. By adjusting these parameters, the system can tolerate the thermal mismatch between materials with different coefficients of thermal expansion while maintaining structural integrity.
3Weight of moving object
If different materials are used between adjacent aircraft sections, then weight reduction is improved, but load transfer capability deteriorates
Solution Approach 1:
The joint assembly is segmented into multiple load transfer paths including fasteners, bonding structures, and mechanical interlocks. This segmentation distributes the load transfer function across multiple elements, ensuring that significant loads can be effectively transferred from aluminum wing boxes to composite center sections while maintaining a lightweight design.
Solution Approach 2:
The use of composite materials in the joint assembly and wing sections provides high specific strength (strength-to-weight ratio), enabling effective load transfer without adding excessive weight. The composite structures can be tailored to optimize load path efficiency while maintaining weight reduction benefits.
Data Source
Figure 1~3
Figure 4~7
Figure 8~9
AI summary
An upper joint of a wing assembly of an aircraft includes an outboard upper wing panel, a center upper wing panel, a rib, and an upper joint assembly operatively interconnecting the outboard upper wing panel, the center upper wing panel, and the rib. In some embodiments, outboard upper stringers may be configured differently than center upper stringers. In some embodiments, a subset of the center upper stringers may not directly oppose the outboard upper stringers. In other embodiments, for at least a substantial fore/aft span of the upper joint, each of the center upper stringers may directly oppose an outboard upper stringer. In particular the present invention relates to An upper joint for a wing assembly of an aircraft, the upper joint comprising: an outboard upper wing panel (24) of an outboard wing box (20, 22); a center upper wing panel (28) of a wing center section (18); a rib (32) that is located between the outboard wing box and the wing center section; and an upper joint assembly (38) operatively interconnecting the outboard upper wing panel, the center upper wing panel, and the rib; wherein the upper joint assembly defines a mating plane (48) between the outboard wing box and the wing center section; wherein when the upper joint is in compression, the outboard upper wing panel expresses a compressive inward pressure toward the upper joint assembly; wherein when the upper joint is in compression, the center upper wing panel expresses a compressive outward pressure toward the upper joint assembly; and wherein a centroid (54) of the compressive inward pressure (50) across an acreage of the outboard upper wing panel when extended across the mating plane intersects the mating plane below or above where a centroid (56) of the compressive outward pressure (52) across an acreage of the center upper wing panel when extended across the mating plane intersects the mating plane.