An A380 wing panel is being assembled on this automated line using Electroimpact E4380 automatic drilling and insertion systems for permanent fastener installation. The machines clamp the skin and stringer together, drill holes, insert and form aluminum rivets. They also drill and coldwork holes and then insert titanium pins or lockbolts.
That's true of course. The question is, given an increase in composite use, whether fasteners will be used in high enough quantities in repair to make up for the lower overall quantities in manufacturing.
Excellent post Ann. I know the longevity of any fastener is dependent upon the application and use. Relative to composite fasteners, do we know how they "stack up" relative to metal fasteners? I have seen no data that tries to correlate life cycles of either type. Great point also about the grounding of composites. I know this must be a huge issue but not talked about too much in the literature.
Glad you liked the article. The whole issue of the grounding of composites used in aircraft has been widely misunderstood, so I thought it was a good idea to include some clear discussion on that issue. Could you clarify your question about comparisons between fasteners for composites and fasteners for metal? What sort of comparisons do you have in mind?
I never thought that lightening strikes on aircraft was so common. I read that it happens 2 times per year on average, per airplane. I have seen electrical discharge responsible for fastener loosening and in some cases, ejecting.
There is a downside to composite pieces, price. Bolting parts together will always be around. I designed a mechanical system that ended up having over 60 bolts.. it was cheaper than with none, that was for sure.
The lightning strike issue isn't about frequency so much as it is about catastrophic results. If you've only got a (for example) 1% chance of something happening, but that something has catastrophic results--people dying, lawsuits--then that's something you've got to protect against, or at least not encourage, in your materials and assembly process selection.
An MIT research team has invented what they see as a solution to the need for biodegradable 3D-printable materials made from something besides petroleum-based sources: a water-based robotic additive extrusion method that makes objects from biodegradable hydrogel composites.
Alcoa has unveiled a new manufacturing and materials technology for making aluminum sheet, aimed especially at automotive, industrial, and packaging applications. If all its claims are true, this is a major breakthrough, and may convince more automotive engineers to use aluminum.
NASA has just installed a giant robot to help in its research on composite aerospace materials, like those used for the Orion spacecraft. The agency wants to shave the time it takes to get composites through design, test, and manufacturing stages.
The European Space Agency (ESA) is working with architects Foster + Partners to test the possibility of using lunar regolith, or moon rocks, and 3D printing to make structures for use on the moon. A new video shows some cool animations of a hypothetical lunar mission that carries out this vision.
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