Guest PBooty Posted March 14, 2004 Share Posted March 14, 2004 Just thought I'd ask this here, since I know a lot of you guys have random talents... For one of my design classes I need to design and essentially figure out how to manufacture a "boom". Its essentially a axisymmetric hollw part. I've decided on using the Filament winding processes. My problem is, I can't for the life of me figure out how to lay the 0 degree fibers. Does anyone have experience with this that can tell me how to make 0's???? 90 degree - slow rotation, feed to the right +45 degree - fast rotation, feed to the right -45 degree - fast rotation, feed to the left 0 degree - ?????????? Here's an excerpt from my report to help give you guys an idea of whats going on.. "If the boom is to be fabricated, the design would have to be slightly modified. We would be limited to twenty one plies; which means that we would drop the 2% 90 degree plies because the +-45 degree would give it an effectively adequate strength in the hoop direction. The fiber composition would consist of twenty one plies, including eleven 0 degree plies and ten +-45degree plies. The orientation would be a balanced laminate, and because a tubular shape is already symmetric, we would not have to concern ourselves with the symmetry. Ultimately, the pattern would be: [0/-45/0/+45/0]. " Quote Link to comment Share on other sites More sharing options...
blueovalz Posted March 14, 2004 Share Posted March 14, 2004 I love this kind of query. No, I've no formal education in structures or their design in fabrication. An uneducated response (because no question is a stupid question) is "shouldn't it be 90/-45/90/+45/90? I'm assuming from the description that a 90 is nearly parallel with the boom whereas the 0 is wound axially? In your question, are you saying a tightly wound helix (a 0) is structually stronger than the long parallel strands (a 90)? Instead of a Car Talk puzzler, let's have our SEs provide a weekly HybridZ puzzler! OH, What a GREAT IDEA Quote Link to comment Share on other sites More sharing options...
Guest PBooty Posted March 14, 2004 Share Posted March 14, 2004 as far as 0's and 90's go, I can't go as far as saying that one is "stronger" than the other, since their orientation is based on their structural requirements (ie. bending moments, torsion, and so on..) To clerify, incase I wasn't clear, 90's are perpendicular to the axis, and zero's are parrallel.. Uhhh..I think i'll add more detail later to help clerify back to studying multiphase fluid flow i go Quote Link to comment Share on other sites More sharing options...
Guest PBooty Posted March 15, 2004 Share Posted March 15, 2004 so no one knows how to lay 0 degree plies using filament winding???? Quote Link to comment Share on other sites More sharing options...
A. G. Olphart Posted March 15, 2004 Share Posted March 15, 2004 Logically, it would seem to require a specially built machine, somewhat akin to a loom, in which a shuttle could be tossed back and forth whilst indexing the head for thread width. This could be done around rings at each end of the part; through the inside one direction, and back the other direction on the outside. Could one pass in each direction be done between two fixed rings, then put under tension to act as a spool on which to wind your +45 and - 45 layers? Personally I wouldn't think so, as any tension on your supply for the +45 and - 45 layers would tend to pull the tube smaller and smaller as the part winds. So, were the shuttle method to be instituted, it looks like it would require a spool/core/pipe as a form around which to wind. Could you wind around a core of thermoplastic, which would then be incorporated into the part in a hot mold, or is this a thermosetting only deal? Alternatively, you are left with winding the 0 layers on the outside with a magically fast carriage feed and a myriad of magic fingers to hold the ends of the passes in place (at the ends of your boom/tube) until the next 45 or 90 layer takes over that job... In short, I don't see this a practical solution. Can you gain sufficient strength longitudinally by just laying your 45's out flatter and avoid the 0 layers? Fun to contemplate, but all is conjecture. Quote Link to comment Share on other sites More sharing options...
Guest PBooty Posted March 19, 2004 Share Posted March 19, 2004 In case anyone is intereseted... I asked my Design Professor and he said that the easiest way would be to do it by hand... who knew that was an option... Quote Link to comment Share on other sites More sharing options...
A. G. Olphart Posted March 19, 2004 Share Posted March 19, 2004 I beleive that's professorese for "This is an engineering exercise; We ain't gonna build no steenkeeng parts". Quote Link to comment Share on other sites More sharing options...
pparaska Posted March 19, 2004 Share Posted March 19, 2004 It can be done. I just typed a huge response that got nixed because my login timed out. Sorry, no time to do that again. Quote Link to comment Share on other sites More sharing options...
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