Aircraft Pressure Bulkhead Energy Absorption for Hydrogen Crash Loads
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional pressure bulkheads in aircraft fuselages do not effectively absorb crash energy, particularly in hydrogen-powered aircraft configurations where the bulkhead is located before the rear end to accommodate hydrogen tanks, leading to potential structural deformations during impact scenarios.
Innovation Solution
Integrating an energy absorbing section into the pressure bulkhead device that allows for kinetic energy absorption through plastic deformation and progressive structural failure, with a structural unit extending in the vertical direction to enhance crash energy absorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the pressure bulkhead is arranged before the rear end portion to accommodate hydrogen tanks in the aft fuselage, then the hydrogen tanks can be positioned in the caudal configuration, but the pressure bulkhead becomes involved in structural deformations during impact scenarios and cannot effectively absorb crash energy
Solution Approach 1:
The pressure bulkhead is segmented into a rigid upper portion and a deformable lower portion. The deformable lower portion is specifically designed to absorb crash energy through controlled deformation, while the rigid upper portion maintains structural integrity and pressure containment. This segmentation allows the bulkhead to serve dual functions: maintaining pressurization and absorbing impact energy.
Solution Approach 2:
Different portions of the pressure bulkhead are assigned different mechanical properties. The lower portion near the engine mount is designed with deformable characteristics to absorb impact energy, while the upper portion maintains rigid properties for structural support. This local differentiation of material properties enables the bulkhead to address both crash energy absorption and structural stability requirements.
2Stress or pressure
If the pressure bulkhead is made rigid to maintain pressurization, then the pressurizable compartment can maintain internal pressure, but the bulkhead cannot absorb impact energy and may suffer structural deformations during crash scenarios
Solution Approach 1:
The pressure bulkhead is divided into functionally distinct segments: a rigid upper segment for maintaining pressurization and a deformable lower segment for energy absorption. This segmentation allows each portion to optimize its mechanical properties for its specific function without compromising the other.
Solution Approach 2:
The bulkhead exhibits spatially varying mechanical properties, with the lower portion designed for deformability and the upper portion for rigidity. This local quality differentiation enables the structure to simultaneously maintain pressure containment while absorbing impact energy through controlled deformation in the appropriate region.
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
The energy absorbing section enables continuous deformation along the aircraft fuselage's longitudinal direction, improving overall crash behavior and absorbing energy more homogeneously, especially in regions behind the center of the aircraft.
Implementation Method 1
the energy absorbing section or energy absorbing mechanism, respectively, is configured to absorb impact energy by a plastic deformation and/or by progressive structural failure
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The present invention provides a pressure bulkhead device (1) for an aircraft fuselage (10), the pressure bulkhead device (1) comprising: a first side (2) extending along a vertical direction (Zb) and facing a pressurizable compartment; a second side (3) arranged opposite the first side (2), wherein the first side (2) is pressurizable with an internal pressure that is higher than an ambient pressure being present at the second side (3); and an energy absorbing section (4) [or energy absorbing mechanism, respectively], which is configured to absorb impact energy, and is arranged at least at a lower end region (5) of the first side (2) and the second side (3) in relation to the vertical direction (Zb). Further the present invention provides an aircraft fuselage (10) comprising such a pressure bulkhead device (1) as well as an aircraft (100) comprising such an aircraft fuselage (10).