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Gravitational effects on closed-cellular-foam microstructure
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Cronise, Raymond J. Wessling, Francis C. Mathews, John McMannus, Samuel P. Patel Sr., Darayas Noever, David A. |
| Copyright Year | 1996 |
| Description | Polyurethane foam has been produced in low gravity for the first time. The cause and distribution of different void or pore sizes are elucidated from direct comparison of unit-gravity and low-gravity samples. Low gravity is found to increase the pore roundness by 17% and reduce the void size by 50%. The standard deviation for pores becomes narrower (a more homogeneous foam is produced) in low gravity. Both a Gaussian and a Weibull model fail to describe the statistical distribution of void areas, and hence the governing dynamics do not combine small voids in either a uniform or a dependent fashion to make larger voids. Instead, the void areas follow an exponential law, which effectively randomizes the production of void sizes in a nondependent fashion consistent more with single nucleation than with multiple or combining events. |
| File Size | 524255 |
| Page Count | 8 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19970021685 |
| Archival Resource Key | ark:/13960/t9t19xz1p |
| Language | English |
| Publisher Date | 1996-04-01 |
| Access Restriction | Open |
| Subject Keyword | Materials Processing Nucleation Gravitational Effects Statistical Distributions Product Development Porosity Microstructure Microgravity Weibull Density Functions Failure Polyurethane Foam Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
