[Cleanup] Force mumin=0

dune/tectonic/frictiondata.hh

@@ -9,7 +9,6 @@ struct FrictionData {
         a(parset.get<double>("a")),
         b(parset.get<double>("b")),
         mu0(parset.get<double>("mu0")),
-        mumin(parset.get<double>("mumin")),
         normalStress(normalStress) {}
 
   double const L;
@@ -17,7 +16,6 @@ struct FrictionData {
   double const a;
   double const b;
   double const mu0;
-  double const mumin;
   double const normalStress;
 };
 #endif

dune/tectonic/frictionpotential.hh

@@ -38,7 +38,7 @@ class FrictionPotential : public FrictionPotentialWrapper {
   double differential(double V) const {
     assert(V >= 0.0);
     if (V <= V_cutoff)
-      return fd.mumin;
+      return 0.0;
 
     return weightTimesNormalStress * fd.a * (std::log(V) - logV_m);
   }
@@ -62,9 +62,10 @@ class FrictionPotential : public FrictionPotentialWrapper {
   }
 
   void updateLogState(double logState) {
-    logV_m = std::log(fd.V0) +
-             (-(fd.mu0 + fd.b * (logState + std::log(fd.V0 / fd.L))) / fd.a);
-    V_cutoff = std::exp(logV_m + fd.mumin / fd.a);
+    double const tmp =
+        (fd.mu0 + fd.b * (logState + std::log(fd.V0 / fd.L))) / fd.a;
+    logV_m = std::log(fd.V0) - tmp;
+    V_cutoff = fd.V0 / std::exp(tmp);
   }
 
 private:

src/one-body-sample.parset

@@ -17,7 +17,6 @@ bulkViscosity  = 0
 
 [boundary.friction]
 mu0          = 0.6
-mumin        = 0.0
 a            = 0.010
 b            = 0.015
 V0           = 1e-6