Aircraft Cabin Door Internal Force-Absorbing Frame
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing aircraft pressurized cabin doors are difficult and costly to manufacture due to complex intersections between transversal beams and stringers, and they are challenging to produce in composite materials, while also being heavy and complex.
Innovation Solution
A pressurized cabin door design featuring two circumferential beams on the lateral edges and a plurality of longitudinal beams between them, with an internal force-absorbing frame that connects these beams without intersecting profiles, allowing for simplified assembly and use of composite materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If transversal beams and stringers are intersecting to form a rigid structure, then the door achieves high rigidity, but the manufacturing complexity and cost increase significantly
Solution Approach 1:
The door structure is divided into separate longitudinal beams and circumferential beams that do not intersect, but are instead connected through a simplified joint system. This segmentation eliminates the complex intersections while maintaining structural integrity through the distributed beam arrangement.
Solution Approach 2:
The longitudinal beams and circumferential beams are merged into a unified structure where the beams are fixed to each other at their intersections, creating a rigid framework without requiring complex fastening systems. The beams are dimensioned to directly support the skin and withstand pressure loads.
2Strength
If intersecting connections are used between beams, then structural rigidity is improved, but manufacturing cost and time increase
Solution Approach 1:
The structure uses segmented beams that are fixed to each other rather than requiring complex intersecting connections. The longitudinal beams are fixed to the circumferential beams in a simplified manner that reduces manufacturing complexity while maintaining the necessary structural strength.
3Stability of the object's composition
If complex intersections are implemented, then the door achieves high rigidity, but the ability to manufacture in composite materials is reduced
Solution Approach 1:
The door structure uses segmented longitudinal and circumferential beams that are fixed to each other rather than requiring complex intersections. This segmentation simplifies the manufacturing process for composite materials, as the beams can be manufactured separately and then assembled, avoiding the difficulties of creating complex intersecting structures in composite materials.
4Device complexity
If monolithic door design is used, then manufacturing complexity is reduced, but the weight increases substantially
Solution Approach 1:
The door structure is segmented into multiple beams (longitudinal and circumferential) that are fixed to each other, rather than being a single monolithic piece. This segmentation allows for optimized material distribution and reduced weight while maintaining structural rigidity and simplifying manufacturing processes.
Data Source
AI summary
An aircraft pressurized cabin door (1) having a fuselage panel (2) and a door structure (3) that includes: two circumferential beams (4) arranged on the lateral edges of the door (1); a plurality of longitudinal beams (5). Each longitudinal beam (5) is an open profile having an outer face to which the fuselage panel (2) is fixed and an inner face, the door structure (3) further including an internal force-absorbing frame (12) fixed to the inner face of each longitudinal beam (5), this internal force-absorbing frame (12) having a plurality of uprights (13) each extending opposite a circumferential beam (4), each upright (13) being fixed to several longitudinal beams (5).