Passive dynamic structure damage control in a hydraulic ram environment
US5934618A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 1, 1995 |
| Grant date | Aug 10, 1999 |
| Priority date | — |
| Expiry date | Dec 1, 2015 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB64D2037/325
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
An aircraft fuel tank construction for providing enhanced fuel tank survivability and aircraft structural integrity when the fuel tank is penetrated by an exploding projectile, utilizes selective placement of low density, fluid-displacing material to create a low shock impedance region which decouples protected fuel tank structure from the destructive effects of a shock wave. The low shock impedance region may be formed using closed cell foam, or using isolators comprising bladders inflated with a compressible, inert gas. Such bladders should have a wedge shape and a wedge angle of at least 15 degrees. Precise shape is less important with closed cell foam. Polymethylacrilimide has been shown to be particularly effective for this purpose. Finite element analysis is useful in tuning the design of actual low shock impedance regions for actual aircraft designs. This construction is especially useful in fuel tanks manufactured from composite materials where tank wall pull-off from internal spars and stiffeners is the primary mode of catastrophic structural failure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.