[JoeF]

Spars for Hang Gliders
Explore spars for hang gliders. Historical spars? Options? Possible? Tests? Types? Materials? Applications in a HG? Main wing spars?Rib spars? Compression spars?
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https://en.wikipedia.org/wiki/Spar_(aeronautics)

[JoeF]

Joining a subtopic of our forum this spars topic: Coilable Battens and Coilable Spars.

Other specialty subtopics. under "Spars" may be started as interest forms such. Perhaps one day a focussed subtopic may deal with string truss spars. We have notes sprinkled in other topics that face splinted inflated spars, inflatable spars, aluminum spars, carbon-fiber reinforced plastic spars, fiberglass spars, steel spars, bamboo spars, etc.
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Trained engineers are invited to advance the study and discussion of hang glider spars.
Users of spars are invited to tell of experiences.
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The most used spars in contemporary hang gliding use alloys of aluminum. Awareness of precise specifications for a spar may help a wing owner to care for the spar. So, is it easy know what are the specifications for any given hang glider using aluminum? How much information is not available? Maybe a database could collect data and be available easily to all seekers. Owners might report on the wing they have.

Pere Casellas in his Laboratori d'envol has fertile notes: http://www.laboratoridenvol.com/info3/i ... es.en.html

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When to replace a spar? Inspection challenges?
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What are the effects of changing a spar from aluminum to carbon fiber reinforced plastic? What new cares result from the mod? Inspection changes? Handling changes? Mass changes? Weight changes? Flight-performance changes? Cost?
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[JoeF]

Design, characterization, control, and optimization of a ‘super string’ deployable truss structure
Buckler, Matthew S. 
 University of Maryland, Baltimore County ProQuest Dissertations Publishing,  2009
https://www.proquest.com/openview/a38af ... &cbl=18750

[JoeF]

An option for a complex spar by EnergyKiteSystems toward "One-Meter HG Pack Club" is rehearsed in this post:

The rib-bulkhead part has a means to stay the position of the ends of the hard compression segment beams of one-meter length. The rib-bulkhead from nose to its truncated aft end is one meter. The receivers at the aft end of the rib bulkhead receives upper and lower aft rib battens; the battens will be in compression pushed by the HG's sail. The max stow length of the rib battens will be one meter. Wingtip wand will have max length of one meter, but may have an inserted extension that makes for an effective longer-than-one-meter wingtip, but packs will be at most one meter in length. The rib bulkheads will stack in pack along with compression beams and battens. Pack will hold kingpost and queenpost beams made up of beams no longer than one meter. High Hat parts will be less than one meter. Rigging lines will pack well also. Kp-Qp rigging will set wing position and allow mass reductions. The wing DS covering holds the shown complex spar in the sails' interior. The black vertical beam at each rib bulkhead is a hard compression beam. The number of rib-bulkheads may vary. The drawing suggests a 9-meter span for the wing, but this may vary per experiment; I will explore 5-m, 6-m, 7-m, 8-m, 9-m, 10-m versions as time permits.

Note: As these drawsings and notes have been suggesting the black compression segments be 1-meter in length, other lengths may be employed to build up a similar complex spar; e.g., instead of 1 meter, maybe 5-ft long segments. And further, say one chooses the 1-meter compression-element length; then still a rib bulkhead could be placed at the center of the 1-meter beam. A bulkhead is important to be at the ends of the compression element segments for anchoring the segments, but mid-segment bulkheads of lighter material may be used to help in airfoil formation. Maybe have two thin bulkheads in mid-beam between the key at-segmentation stations.

Anyone is welcome to develop HGs using the EnergyKiteSystems complex spar.

Caution: negative g loads are handled lightly; the close-to-compression-elements-hugging webbing uses only the cross-section of the compression elements as blocking mechanism; the Kp-Qp rigging aids in the neg-g loading demands; some stay lines and the DS-wing covering also helps some in the neg-g management.
,

SegmentedOneMeterSparThickAirfoilMainBulkheadedRib001.jpg (104.17 KiB) Viewed 402 times

This may also be used when no rib bulkhead is explored in which case the low feet of the two or more vertical spreaders could be tensionally bound or beam bound. Long flight tension lines would go from wing tip to wing tip and be grabbed by the feet of the vertical spreaders.

TwoOrMoreSpreadersBelowCompressionElementsAtRibBulkheadStations.jpg (38.67 KiB) Viewed 401 times

This drawing does not show the green dot that would be at the foot of the two or more generally vertical spreaders; the green dot would indicate the wing-spanwise flight lines that make up the complex spar.

BroadSpreaderMultipleFlightLinesComplexSparEnergyKiteSystems.jpg (29.13 KiB) Viewed 401 times

[JoeF]

Extending the above rehearsal:
Consider 2 in (5.08 cm) long interior sleeve for the compression tubes of 1 m length. Have interior stops bonded in ends of the compression beams; allow 1/8 in for sleeve play. Place the interior sleeves at site assembly to make a full, say 8 m assembly. Wrap the neg-g webbing on the 8 m subassembly. Stretch the subassembly of rib bulkheads that have the stay lines and flight lines of the complex spar perma-integrated; use two environment anchors to do the stretching; the stretching intended should have the bulkheads standing upright. While that bulkhead-lines subassembly is sitting on the ground stretched, such is receptive to placing the the 8-m run of sleeved segments into ready notches of the bulkheads. Set the left ends of the subassemblies together; then set the right ends of the subassemblies together. At that point one has the ready complex 8-m spar.

Above procedure in briefer terms:
From tiny pack take parts and and form the complex spar:
1. Marry compression beam segments with sleeves.
2. Mount neg-g webbing onto 8-m subassembly.
3. Stretch bulkhead-lines subassembly using two environment anchors.
4. Combine the two long subassemblies.
5. Disconnect the complex spar from the two environment anchors. Store the two lines that were used to environmentally anchor and stretch the bulkhead-lines subassembly.
6. Finish Kp-Qp rigging.
7. Set hang loop.
8. Don harness and helmet
9. Check all matters.
10. Check flight conditions.
11. Hook in. Check conditions. Get into launch position; hook-in check. Check conditions again. If checks are good, then commit flight.

Again, more briefly. Arrive at site. Form complex spar. Mount DS sail. Insert aft ribs, set to TE of sail. Rig Kp-Qp, TCF, and landing lines and flight lines. Do flight check. Hook-in. Check people, wind, self, plan. Check hook-in. Final review. Step into the sky and fly.

Again, more briefly yet:
Bus, hike, arrive at site. Put wing up. Fly.
Put wing away into a one-meter pack. Hike, bus, arrive at home. Sleep well.

Again, yet briefer:
Bus-hike with One-Meter HG Pack to launch site. Wing up. Hook-in. Fly.
Reverse steps. Sleep well.

Again, briefer: Enjoy being a member of the One-Meter Pack HG Club.

Briefer: Hang glide. Launch, glide, land.

Briefer: Fly.

Thank you, God. Thank you, Otto Lilienthal. Thank you, birds and insects. Thank you, Mom and Dad. Thank you, Aviation Community. Thank you, Self-Soar Association. Thank you, AWE community. Thank you, EnergyKiteSystems. Thank you, U.S. Hawks fellowship.
"

Did anyone say: "Test things to meet flight performance calls."