From c2e310dcea58166574c9538a5f7ee16932277a6d Mon Sep 17 00:00:00 2001
From: Dmitri Naumov <dmitri.naumov@ufz.de>
Date: Mon, 22 May 2017 20:30:36 +0200
Subject: [PATCH] [MatL] Ehlers simplify sqrt(a)^3 to a*sqrt(a).
---
MaterialLib/SolidModels/Ehlers-impl.h | 19 +++++++++----------
1 file changed, 9 insertions(+), 10 deletions(-)
diff --git a/MaterialLib/SolidModels/Ehlers-impl.h b/MaterialLib/SolidModels/Ehlers-impl.h
index 4e1148daea0..52bbbf5e7dc 100644
--- a/MaterialLib/SolidModels/Ehlers-impl.h
+++ b/MaterialLib/SolidModels/Ehlers-impl.h
@@ -193,14 +193,13 @@ double yieldFunction(MaterialProperties const& mp,
double const I_1_squared = boost::math::pow<2>(s.I_1);
assert(s.J_2 != 0);
- return std::sqrt(s.J_2 *
- std::pow(1 +
- mp.gamma * s.J_3 /
- boost::math::pow<3>(std::sqrt(s.J_2)),
- mp.m) +
- mp.alpha / 2. * I_1_squared +
- boost::math::pow<2>(mp.delta) *
- boost::math::pow<2>(I_1_squared)) +
+ return std::sqrt(
+ s.J_2 *
+ std::pow(1 + mp.gamma * s.J_3 / (s.J_2 * std::sqrt(s.J_2)),
+ mp.m) +
+ mp.alpha / 2. * I_1_squared +
+ boost::math::pow<2>(mp.delta) *
+ boost::math::pow<2>(I_1_squared)) +
mp.beta * s.I_1 + mp.epsilon * I_1_squared - k;
}
@@ -227,7 +226,7 @@ calculatePlasticResidual(
auto const& P_dev = Invariants::deviatoric_projection;
auto const& identity2 = Invariants::identity2;
- double const theta = s.J_3 / boost::math::pow<3>(std::sqrt(s.J_2));
+ double const theta = s.J_3 / (s.J_2 * std::sqrt(s.J_2));
typename SolidEhlers<DisplacementDim>::ResidualVectorType residual;
// calculate stress residual
@@ -285,7 +284,7 @@ typename SolidEhlers<DisplacementDim>::JacobianMatrix calculatePlasticJacobian(
auto const& P_dev = Invariants::deviatoric_projection;
auto const& identity2 = Invariants::identity2;
- double const theta = s.J_3 / boost::math::pow<3>(std::sqrt(s.J_2));
+ double const theta = s.J_3 / (s.J_2 * std::sqrt(s.J_2));
OnePlusGamma_pTheta const one_gt{mp.gamma_p, theta, mp.m_p};
// inverse of deviatoric stress tensor
--
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