Composite Spar Structure for Fitting-Free Fuselage Load Transfer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing solutions for joining horizontal structures to an aircraft fuselage require the use of metal fittings and accessories, leading to increased assembly and maintenance efforts and weight.
Innovation Solution
The use of composite spars made of carbon fiber-reinforced plastic that integrate structural functions of a longitudinal member and frame member in a single piece, allowing efficient load transfer without metal fittings, using a web, upper and lower flanges, and distal ends with curved edges for connection to the aircraft fuselage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If metal fittings and accessories are used to join horizontal structures to the aircraft fuselage, then load transfer is achieved, but assembly and maintenance efforts increase and weight increases
Solution Approach 1:
The patent merges the longitudinal member and frame member into a single integrated composite spar component. This integration eliminates the need for separate metal fittings and accessories, reducing assembly complexity while maintaining load transfer capability through the unified composite structure's designed geometry and material properties
Solution Approach 2:
The patent employs composite materials (carbon fiber reinforced plastic) to create a spar that combines the structural functions of both longitudinal and frame members. The composite material provides sufficient strength for load transfer while enabling a streamlined, fitting-free design that reduces assembly and maintenance efforts
2Strength
If metal fittings and accessories are used to join horizontal structures to the aircraft fuselage, then load transfer is achieved, but the weight of the aircraft structure increases
Solution Approach 1:
The patent uses composite materials (carbon fiber reinforced plastic) that provide high strength-to-weight ratio. This allows the spar to achieve the necessary load transfer capability while significantly reducing the weight compared to traditional metal fittings and accessories
Solution Approach 2:
By combining multiple structural functions into a single integrated composite spar, the design eliminates redundant metal components, thereby reducing overall weight while maintaining structural integrity and load transfer performance
3Device complexity
If composite spars are used to integrate structural functions, then assembly effort is reduced, but manufacturing complexity increases
Solution Approach 1:
The patent segments the composite spar into distinct geometric zones (web, flanges, end portions) with specific structural functions. This segmentation allows for optimized manufacturing of each zone while maintaining overall integration, balancing manufacturing complexity with assembly simplicity
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
Composite spar (100) for horizontal structures external to the fuselage of an aircraft, the composite spar (100) comprising a web (110) configured as a longitudinal element, upper and lower flanges (110a) and two distal ends, wherein for each end, the composite spar (100) comprises an end portion (105) established in the longitudinal direction of the web (110), and a curved-edged end portion (120) with curved flanges (120a) and a truncated section (125) established in the transverse direction of the web (110), wherein the truncated section (125) is connectable to a frame of the fuselage of the aircraft and configured as a load transfer element between the web (110) and the frame, and wherein one or more of the lower flanges (110a) are connected to the curved flanges (120a).