From 76e343d54d5eea6f19247a25f6203ed9fe286235 Mon Sep 17 00:00:00 2001
From: Arne Morten Kvarving <arne.morten.kvarving@sintef.no>
Date: Wed, 5 Feb 2025 11:30:20 +0100
Subject: [PATCH] store stress as a VoigtArray in MechContainer

---
 opm/simulators/flow/MechContainer.cpp | 45 +++++++++++++--------------
 opm/simulators/flow/MechContainer.hpp |  9 ++----
 2 files changed, 24 insertions(+), 30 deletions(-)

diff --git a/opm/simulators/flow/MechContainer.cpp b/opm/simulators/flow/MechContainer.cpp
index 4aff1d304..f6d0cb2e2 100644
--- a/opm/simulators/flow/MechContainer.cpp
+++ b/opm/simulators/flow/MechContainer.cpp
@@ -50,18 +50,20 @@ allocate(const std::size_t bufferSize,
                       rstKeywords[std::string{"DISP"} + suffix[is++]] = 0;
                   });
 
-    this->stressXX_.resize(bufferSize, 0.0);
-    rstKeywords["STRESSXX"] = 0;
-    this->stressYY_.resize(bufferSize, 0.0);
-    rstKeywords["STRESSYY"] = 0;
-    this->stressZZ_.resize(bufferSize, 0.0);
-    rstKeywords["STRESSZZ"] = 0;
-    this->stressXY_.resize(bufferSize, 0.0);
-    rstKeywords["STRESSXY"] = 0;
-    this->stressXZ_.resize(bufferSize, 0.0);
-    rstKeywords["STRESSXZ"] = 0;
-    this->stressYZ_.resize(bufferSize, 0.0);
-    rstKeywords["STRESSYZ"] = 0;
+    auto resizeAndRegister =
+        [&rstKeywords,bufferSize](auto& tensor,
+                                  const std::string& name)
+    {
+        static constexpr auto fields = std::array{
+            "XX", "YY", "ZZ", "YZ", "XZ", "XY",
+        };
+        tensor.resize(bufferSize);
+        for (const auto& f : fields) {
+            rstKeywords[name + f] = 0;
+        }
+    };
+
+    resizeAndRegister(stress_, "STRESS");
 
     this->strainXX_.resize(bufferSize, 0.0);
     rstKeywords["STRAINXX"] = 0;
@@ -145,12 +147,7 @@ void MechContainer<Scalar>::
 assignStress(const unsigned globalDofIdx,
              const Dune::FieldVector<Scalar,6>& stress)
 {
-    this->stressXX_[globalDofIdx] = stress[0];
-    this->stressYY_[globalDofIdx] = stress[1];
-    this->stressZZ_[globalDofIdx] = stress[2];
-    this->stressYZ_[globalDofIdx] = stress[3];
-    this->stressXZ_[globalDofIdx] = stress[4];
-    this->stressXY_[globalDofIdx] = stress[5];
+    this->stress_.assign(globalDofIdx, VoigtContainer<Scalar>(stress));
 }
 
 template<class Scalar>
@@ -206,12 +203,12 @@ outputRestart(data::Solution& sol) const
         DataEntry{"STRAINXY", UnitSystem::measure::identity, strainXY_},
         DataEntry{"STRAINXZ", UnitSystem::measure::identity, strainXZ_},
         DataEntry{"STRAINYZ", UnitSystem::measure::identity, strainYZ_},
-        DataEntry{"STRESSXX", UnitSystem::measure::length,   stressXX_},
-        DataEntry{"STRESSYY", UnitSystem::measure::length,   stressYY_},
-        DataEntry{"STRESSZZ", UnitSystem::measure::length,   stressZZ_},
-        DataEntry{"STRESSXY", UnitSystem::measure::length,   stressXY_},
-        DataEntry{"STRESSXZ", UnitSystem::measure::length,   stressXZ_},
-        DataEntry{"STRESSYZ", UnitSystem::measure::length,   stressYZ_},
+        DataEntry{"STRESSXX", UnitSystem::measure::length,   stress_[VoigtIndex::XX]},
+        DataEntry{"STRESSYY", UnitSystem::measure::length,   stress_[VoigtIndex::YY]},
+        DataEntry{"STRESSZZ", UnitSystem::measure::length,   stress_[VoigtIndex::ZZ]},
+        DataEntry{"STRESSXY", UnitSystem::measure::length,   stress_[VoigtIndex::XY]},
+        DataEntry{"STRESSXZ", UnitSystem::measure::length,   stress_[VoigtIndex::XZ]},
+        DataEntry{"STRESSYZ", UnitSystem::measure::length,   stress_[VoigtIndex::YZ]},
         DataEntry{"TEMPPOTF", UnitSystem::measure::pressure, potentialTempForce_},
     };
 
diff --git a/opm/simulators/flow/MechContainer.hpp b/opm/simulators/flow/MechContainer.hpp
index a15e49eb3..03a112225 100644
--- a/opm/simulators/flow/MechContainer.hpp
+++ b/opm/simulators/flow/MechContainer.hpp
@@ -28,6 +28,8 @@
 
 #include <dune/common/fvector.hh>
 
+#include <opm/simulators/utils/VoigtArray.hpp>
+
 #include <array>
 #include <cstddef>
 #include <map>
@@ -69,12 +71,7 @@ public:
     ScalarBuffer potentialTempForce_;
 
     std::array<ScalarBuffer,3> disp_;
-    ScalarBuffer stressXX_;
-    ScalarBuffer stressYY_;
-    ScalarBuffer stressZZ_;
-    ScalarBuffer stressXY_;
-    ScalarBuffer stressXZ_;
-    ScalarBuffer stressYZ_;
+    VoigtArray<Scalar> stress_;
     ScalarBuffer delstressXX_;
     ScalarBuffer delstressYY_;
     ScalarBuffer delstressZZ_;