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Deflection-compensating beam for use inside a cylinder
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Goodman, Dwight Myers, Neill Herren, Kenneth |
| Copyright Year | 2008 |
| Description | A design concept for a beam for a specific application permits variations and options for satisfying competing requirements to minimize certain deflections under load and to minimize the weight of the beam. In the specific application, the beam is required to serve as a motion-controlled structure for supporting a mirror for optical testing in the lower third portion of a horizontal, cylindrical vacuum chamber. The cylindrical shape of the chamber is fortuitous in that it can be (and is) utilized as an essential element of the deflection-minimizing design concept. The beam is, more precisely, a table-like structure comprising a nominally flat, horizontal portion with vertical legs at its ends. The weights of the beam and whatever components it supports are reacted by the contact forces between the lower ends of the legs and the inner cylindrical chamber wall. Whereas the bending moments arising from the weights contribute to a beam deflection that is concave with its lowest point at midlength, the bending moments generated by the contact forces acting on the legs contribute to a beam deflection that is convex with its highest point at midlength. In addition, the bending of the legs in response to the weights causes the lower ends of the legs to slide downward on the cylindrical wall. By taking the standard beam-deflection equations, combining them with the geometric relationships among the legs and the horizontal portion of the beam, and treating the sliding as a component of deflection, it is possible to write an equation for the net vertical deflection as a function of the load and of position along the beam. A summary of major conclusions drawn from the equation characterization is included. |
| File Size | 193794 |
| Page Count | 1 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20090020614 |
| Archival Resource Key | ark:/13960/t84j5gf3q |
| Language | English |
| Publisher Date | 2008-01-01 |
| Access Restriction | Open |
| Subject Keyword | Structural Mechanics Bending Moments Vacuum Chambers Deflection Cylindrical Chambers Beams Supports Mirrors Motion Stability Loads Forces Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
