From 6451d929a818750c2b12a7ff62d41e5def50f731 Mon Sep 17 00:00:00 2001
From: Theodore Chang <tlcfem@gmail.com>
Date: Tue, 17 Oct 2023 05:05:48 +0200
Subject: [PATCH] Narrow interval

---
 Material/Material3D/Concrete/CDPM2.cpp | 8 +++++---
 Material/Material3D/Concrete/CDPM2.h   | 2 +-
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/Material/Material3D/Concrete/CDPM2.cpp b/Material/Material3D/Concrete/CDPM2.cpp
index d21959ffe..605452bca 100644
--- a/Material/Material3D/Concrete/CDPM2.cpp
+++ b/Material/Material3D/Concrete/CDPM2.cpp
@@ -395,16 +395,18 @@ int CDPM2::update_trial_status(const vec& t_strain) {
                 gamma = 0.;
                 approx_update();
 
-                gamma = f / (pfps * double_shear * gs + pfpp * bulk * gp + pfpkp * gg / xh);
+                gamma = f / elastic_modulus;
+                auto low = 0.;
                 while(true) {
                     approx_update();
                     if(f < 0.) break;
+                    low = gamma;
                     gamma *= 2.;
                 }
 
-                auto low = 0., high = gamma;
+                auto high = gamma;
                 while(true) {
-                    if(fabs(high - low) < std::numeric_limits<float>::epsilon()) break;
+                    if(fabs(high - low) < tolerance) break;
                     gamma = .5 * (low + high);
                     approx_update();
                     (f < 0. ? high : low) = gamma;
diff --git a/Material/Material3D/Concrete/CDPM2.h b/Material/Material3D/Concrete/CDPM2.h
index fd29d026e..b1da3f0a7 100644
--- a/Material/Material3D/Concrete/CDPM2.h
+++ b/Material/Material3D/Concrete/CDPM2.h
@@ -37,7 +37,7 @@ struct DataCDPM2 {
     const double elastic_modulus = 3E4;
     const double poissons_ratio = .3;
     const double ft = 3.;
-    const double fc = 10.;
+    const double fc = 30.;
     const double qh0 = .3;
     const double hp = .05;
     const double df = .85;