make surface an input to spar

convexengineering · Oct 13, 2017 · 7e92c2c · 7e92c2c
1 parent c43fe50
commit 7e92c2c
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Showing 2 changed files with 13 additions and 16 deletions.
diff --git a/gpkitmodels/GP/aircraft/wing/capspar.py b/gpkitmodels/GP/aircraft/wing/capspar.py
@@ -5,7 +5,7 @@
 
 class CapSpar(Model):
     "cap spar model"
-    def setup(self, N):
+    def setup(self, N, surface):
 
         # phyiscal properties
         rhocfrp = Variable("\\rho_{CFRP}", 1.6, "g/cm^3", "density of CFRP")
@@ -16,26 +16,28 @@ def setup(self, N):
             I = Variable("I", "m^4", "spar x moment of inertia")
             Sy = Variable("S_y", "m**3", "section modulus")
             dm = Variable("dm", "kg", "segment spar mass")
-            dmdy = Variable("(dm/dy)", "kg/m", "spar mass per length")
             w = Variable("w", "in", "spar width")
             t = Variable("t", "in", "spar cap thickness")
             tshear = Variable("t_{shear}", "in", "shear web thickness")
 
         W = Variable("W", "lbf", "spar weight")
-        w_lim = Variable("w_{lim}", 0.15, "-", "spar width to chord ratio")
+        wlim = Variable("w_{lim}", 0.15, "-", "spar width to chord ratio")
         tshearmin = Variable("t_{shear-min}", 0.012, "in",
                              "min shear web thickness")
         g = Variable("g", 9.81, "m/s^2", "gravitational acceleration")
         mfac = Variable("m_{fac}", 0.97, "-", "curvature knockdown factor")
         rhofoam = Variable("\\rho_{foam}", 0.036, "g/cm^3", "foam density")
 
-        constraints = [I/mfac <= 2*w*t*(hin/2)**2,
-                       dmdy >= (rhocfrp*(2*w*t + 2*tshear*(w + hin + 2*t))
-                                + rhofoam*w*hin),
-                       W >= 2*dm.sum()*g,
-                       Sy*(hin/2 + t) <= I,
-                       tshear >= tshearmin
-                      ]
+        constraints = [
+            I/mfac <= 2*w*t*(hin/2)**2,
+            dm >= (rhocfrp*(2*w*t + 2*tshear*(w + hin + 2*t))
+                   + rhofoam*w*hin)*surface["b"]/2*surface["d\\eta"],
+            W >= 2*dm.sum()*g,
+            w <= wlim*surface["c_{ave}"],
+            surface["c_{ave}"]*surface["\\tau"] >= hin + 2*t,
+            Sy*(hin/2 + t) <= I,
+            tshear >= tshearmin
+            ]
 
         self.loading = ChordSparL
         self.gustloading = GustL

diff --git a/gpkitmodels/GP/aircraft/wing/wing.py b/gpkitmodels/GP/aircraft/wing/wing.py
@@ -35,18 +35,13 @@ def setup(self, N=5, lam=0.5, hollow=False):
 
         self.surf = AeroSurf(N)
         self.surf.substitutions.update(subdict)
-        self.spar = CapSpar(N)
+        self.spar = CapSpar(N, self.surf)
         self.skin = WingSkin()
         self.components = [self.spar, self.skin]
 
 
         constraints = [
             W/mfac >= sum(c["W"] for c in self.components),
-            self.spar["dm"] >= (self.spar["(dm/dy)"]*self.surf["b"]/2
-                                * self.surf["d\\eta"]),
-            self.spar["w"] <= self.spar["w_{lim}"]*self.surf["c_{ave}"],
-            self.surf["c_{ave}"]*self.surf["\\tau"] >= (
-                self.spar["h_{in}"] + 2*self.spar["t"]),
             self.skin["W"] >= (self.skin["\\rho_{CFRP}"]*self.surf["S"]*2
                                * self.skin["t"]*self.skin["g"]),
             ]