Debonding Stress Concentrations in a Pressurized Lobed Sandwich-Walled Generic Cryogenic Tank
Ko, William L. (2004) Debonding Stress Concentrations in a Pressurized Lobed Sandwich-Walled Generic Cryogenic Tank. Technical Report NASA/TP-2004-212849, Research Engineering, NASA Dryden Flight Research Center.
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Abstract
A finite-element stress analysis has been conducted on a lobed composite sandwich tank subjected to internal pressure and cryogenic cooling. The lobed geometry consists of two obtuse circular walls joined together with a common flat wall. Under internal pressure and cryogenic cooling, this type of lobed tank wall will experience open-mode (a process in which the “honeycomb” is stretched in the depth direction) and shear stress concentrations at the junctures where curved wall changes into flat wall (known as a curve-flat juncture). Open-mode and shear stress concentrations occur in the honeycomb core at the curve-flat junctures and could cause debonding failure. The levels of contributions from internal pressure and temperature loading to the open-mode and shear debonding failure are compared. The lobed fuel tank with honeycomb sandwich walls has been found to be a structurally unsound geometry because of very low debonding failure strengths. The debonding failure problem could be eliminated if the honeycomb core at the curve-flat juncture is replaced with a solid core.
| EPrint Type: | NASA Technical Publication |
|---|---|
| Keywords: | Composite honeycomb sandwich wall, Lobed cryogenic tank, Open-mode debonding, Stress concentrations, Thermocryogenic stress analysis |
| Subjects: | (31 - 39) Engineering: (39) Structural Mechanics |
| ID Code: | 12 |
| Deposited On: | 14 Febuary 2006 |
| Additional Information: | 34 pages. |
