Grain orientation on flat parts

[n7188u]

Should grain orientation on a 1/8" thick 2024-T3 aluminum plate be considered when designing a flat component (such as a strap) which will not be bent?

I am building a Rutan designed aircraft and I am milling the elevator hinge brackets on the canard. They are "L" shaped, with the vertical section of the "L" burried in the canard and the horizontal protruding out of the aft and into the elevator (so the horizontal section of the "L" is catilever). The grain orientation is not specified in the plans and I don't think it is an issue but I want ot learn more about the subject of grain orientation on milled parts.

Chris

 

[jetmaker]

Grain orientation is important in how parts are fabricated. For this reason, sometimes it is more prudent to bend the sheet, or use extrusions or forgings.

Without having a detailed drawing of the part, it is hard to provide a recommendation as to whether orientation is really significant here or not. Typically, if it is not specified on the drawing, or in the parts list, then the design/analysis has already accounted for the worst conditions. Check other drawings, see if they have specific orientations required.

Best luck.

jetmaker

 

[Michael996]

Make the parts exactly as Rutan tells you to do it. If he doesn't give grain orientation, then don't worry about it.

 

[ubrales]

All parts whether flat, formed or drawn are subject to stress. If not, you don't need that part. Therefore, if the direction of grain is unspecified, then, design or fabricate the part such that the stress is along the direction of grain. And similarly bend or form at 90 degrees to the direction of grain. Just good practice.

 

[metman]

Michael996 and ubrales are correct but for future reference, the short tranverse properties for Aluminum alloys are dramatically less than longitudinal direction which will show up in forming or in use if loaded in the weak direction.

Jesus is THE life,
Leonard