122 lines
5.4 KiB
Plaintext
122 lines
5.4 KiB
Plaintext
// Wing Spar
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// In a fixed-wing aircraft, the spar is often the main structural member of the wing, running spanwise at right angles (or thereabouts depending on wing sweep) to the fuselage. The spar carries flight loads and the weight of the wings while on the ground. Other structural and forming members such as ribs may be attached to the spars
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// Set units
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@settings(defaultLengthUnit = mm)
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// Define parameters
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chordLength = 355
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rearSpar = 205
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frontSpar = 33
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upperCamber = 30
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lowerCamber = 18
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foilThickness = 8
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nSections = 5
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sparSpan = 700
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sparStockThicknes = 2.102
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sparBendRadius = 2.102
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// Sketch an airfoil using the chord length, spar positions, and camber heights
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ribSketch = startSketchOn(offsetPlane(-XZ, offset = -foilThickness))
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|> startProfile(at = [chordLength, 0])
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|> line(endAbsolute = [rearSpar, upperCamber])
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|> tangentialArc(endAbsolute = [frontSpar, upperCamber * 1.3])
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|> tangentialArc(endAbsolute = [0, 0])
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|> tangentialArc(angle = 76deg, radius = lowerCamber)
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|> tangentialArc(endAbsolute = [rearSpar, -lowerCamber])
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|> tangentialArc(endAbsolute = [profileStartX(%), profileStartY(%)])
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|> close()
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// Cut circular holes along the chord curve of the airfoil to reduce the mass of each part
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|> subtract2d(tool = circle(center = [62, 9], radius = 17))
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|> subtract2d(tool = circle(center = [113, 10], radius = 19))
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|> subtract2d(tool = circle(center = [164, 9], radius = 17))
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|> subtract2d(tool = circle(center = [228, 5], radius = 11))
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|> subtract2d(tool = circle(center = [260, 3.5], radius = 6.5))
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// Extrude the airfoil to material thicknes, then pattern along the length of the wing spars
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|> extrude(length = -foilThickness)
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|> patternLinear3d(instances = nSections, distance = (sparSpan - (3 * foilThickness)) / (nSections - 1), axis = [0, -1, 0])
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// Model a thin sheet spar with a hemmed top edge for structure
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sparSketch = startSketchOn(-XZ)
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// Sketch the sheet metal profile for the front spar, then extrude
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frontSparProfile = startProfile(sparSketch, at = [frontSpar, -lowerCamber * 0.85])
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|> yLine(endAbsolute = upperCamber, tag = $seg01)
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|> tangentialArc(angle = -90deg, radius = sparBendRadius + sparStockThicknes)
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|> xLine(length = 4, tag = $seg02)
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|> tangentialArc(angle = -90deg, radius = sparBendRadius + sparStockThicknes)
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|> yLine(length = -4, tag = $seg03)
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|> tangentialArc(angle = -90deg, radius = sparBendRadius + sparStockThicknes)
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|> xLine(length = -3, tag = $seg04)
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|> yLine(length = sparStockThicknes)
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|> xLine(length = segLen(seg04))
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|> tangentialArc(angle = 90deg, radius = sparBendRadius)
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|> yLine(length = segLen(seg03))
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|> tangentialArc(angle = 90deg, radius = sparBendRadius)
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|> xLine(length = -segLen(seg02))
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|> tangentialArc(angle = 90deg, radius = sparBendRadius)
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|> yLine(length = -segLen(seg01), tag = $seg10)
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|> line(endAbsolute = [profileStartX(%), profileStartY(%)])
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|> close()
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|> extrude(length = -sparSpan)
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// Sketch the sheet metal profile for the rear spar, then extrude
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rearSparProfile = startProfile(sparSketch, at = [rearSpar, -lowerCamber * 0.7])
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|> yLine(endAbsolute = upperCamber * 0.7, tag = $seg05)
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|> tangentialArc(angle = 90deg, radius = sparBendRadius + sparStockThicknes)
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|> xLine(length = -4, tag = $seg06)
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|> tangentialArc(angle = 90deg, radius = sparBendRadius + sparStockThicknes)
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|> yLine(length = -4, tag = $seg07)
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|> tangentialArc(angle = 90deg, radius = sparBendRadius + sparStockThicknes)
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|> xLine(length = 3, tag = $seg08)
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|> yLine(length = sparStockThicknes)
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|> xLine(length = -segLen(seg08))
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|> tangentialArc(angle = -90deg, radius = sparBendRadius)
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|> yLine(length = segLen(seg07))
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|> tangentialArc(angle = -90deg, radius = sparBendRadius)
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|> xLine(length = segLen(seg06))
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|> tangentialArc(angle = -90deg, radius = sparBendRadius)
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|> yLine(length = -segLen(seg05), tag = $seg09)
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|> line(endAbsolute = [profileStartX(%), profileStartY(%)])
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|> close()
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|> extrude(length = -sparSpan)
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// Cut rectangular holes along the spar length between each rib
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frontSparHoles = startSketchOn(frontSparProfile, face = seg10)
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|> startProfile(at = [-lowerCamber * 0.1, -foilThickness * 3])
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|> xLine(endAbsolute = upperCamber * 0.4, tag = $seg11)
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|> tangentialArc(angle = -90deg, radius = 5)
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|> yLine(endAbsolute = -(sparSpan - (3 * foilThickness)) / (nSections - 1) + 5, tag = $seg12)
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|> tangentialArc(angle = -90deg, radius = 5)
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|> xLine(length = -segLen(seg11))
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|> tangentialArc(angle = -90deg, radius = 5)
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|> yLine(length = segLen(seg12))
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|> tangentialArc(endAbsolute = [profileStartX(%), profileStartY(%)])
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|> close()
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|> patternLinear2d(
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%,
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instances = nSections - 1,
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distance = (sparSpan - (3 * foilThickness)) / (nSections - 1),
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axis = [0, -1],
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)
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|> extrude(length = -10)
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rearSparHoles = startSketchOn(rearSparProfile, face = seg09)
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|> startProfile(at = [-lowerCamber * 0.3, -foilThickness * 3])
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|> xLine(endAbsolute = -upperCamber * 0.01, tag = $seg14)
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|> tangentialArc(angle = -90deg, radius = 5)
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|> yLine(length = -segLen(seg12))
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|> tangentialArc(angle = -90deg, radius = 5)
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|> xLine(length = -segLen(seg14))
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|> tangentialArc(angle = -90deg, radius = 5)
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|> yLine(length = segLen(seg12))
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|> tangentialArc(endAbsolute = [profileStartX(%), profileStartY(%)])
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|> close()
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|> patternLinear2d(
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%,
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instances = nSections - 1,
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distance = (sparSpan - (3 * foilThickness)) / (nSections - 1),
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axis = [0, -1],
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)
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|> extrude(length = -10)
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