Merge branch 'fix/mooneyrivlindensity-square' into 'master'

Correct mistake in mooneyrivlindensity

See merge request !54

dune/elasticity/materials/mooneyrivlindensity.hh

@@ -130,7 +130,7 @@ public:
       {
         //mooneyrivlin_energy is "square"
         field_type detFMinus1 = detF - 1;
-        return strainEnergy + mooneyrivlin_k* detFMinus1 * detFMinus1;
+        return strainEnergy + 0.5 * mooneyrivlin_k* detFMinus1 * detFMinus1;
       }
     }
   }

problems/film-on-substrate-deformation.parset

@@ -97,18 +97,17 @@ mooneyrivlin_12 = 0
 mooneyrivlin_03 = 0
 
 # volume-preserving parameter 
-mooneyrivlin_k = 75e+6
+mooneyrivlin_k = 90e+6
 
 # How to choose the volume-preserving parameter?
 # We need a stretch of 30%  (45e4 10e4 2e4 in x-direction, so a stretch of 45e4*0.3 = 13.5e4)
-# 184 2:1, mooneyrivlin_k = .. and mooneyrivlin_energy = square, neumannValues = 27e4 0 0
-# 184 2:1, mooneyrivlin_k = 57e+6 and mooneyrivlin_energy = log, neumannValues = 27e4 0 0 
+# 184 2:1, mooneyrivlin_k = 90e+6 approximately (depends also on the number of grid levels!) and mooneyrivlin_energy = square or log, neumannValues = 27e4 0 0
 
 mooneyrivlin_energy = square # log, square or ciarlet; different ways to compute the Mooney-Rivlin-Energy
 
 # ciarlet: Fomula from "Ciarlet: Three-Dimensional Elasticity", here no penalty term is 
 # log: Generalized Rivlin model or polynomial hyperelastic model, using  0.5*mooneyrivlin_k*log(det(∇φ)) as the volume-preserving penalty term
-# square: Generalized Rivlin model or polynomial hyperelastic model, using mooneyrivlin_k*(det(∇φ)-1)² as the volume-preserving penalty term
+# square: Generalized Rivlin model or polynomial hyperelastic model, using 0.5*mooneyrivlin_k*(det(∇φ)-1)² as the volume-preserving penalty term
 
 []
 

test/mooneyrivlintest.cc

@@ -149,10 +149,10 @@ int main (int argc, char *argv[])
   parameters["mooneyrivlin_k"] = "75e+6";
 
   parameters["mooneyrivlin_energy"] = "square";
-  double expectedEnergy = 177758377;
-  double expectedGradientTwoNorm = 2.13791422e+09;
-  double expectedGradientInfinityNorm = 599188506;
-  double expectedMatrixFrobeniusNorm = 1.62529884e+11;
+  double expectedEnergy = 167636683;
+  double expectedGradientTwoNorm = 2.10685704e+09;
+  double expectedGradientInfinityNorm = 589695526;
+  double expectedMatrixFrobeniusNorm = 1.61941167e+11;
   int testSquare = assembleAndCompare(basis, parameters, x, expectedEnergy, expectedGradientTwoNorm, expectedGradientInfinityNorm, expectedMatrixFrobeniusNorm);
 
   parameters["mooneyrivlin_energy"] = "log";