diff --git a/Material/Material3D/Concrete/NonlinearCDP.cpp b/Material/Material3D/Concrete/NonlinearCDP.cpp
index 4b1313e97..655362308 100644
--- a/Material/Material3D/Concrete/NonlinearCDP.cpp
+++ b/Material/Material3D/Concrete/NonlinearCDP.cpp
@@ -70,21 +70,21 @@ int NonlinearCDP::update_trial_status(const vec& t_strain) {
 
     trial_stress = (trial_stiffness = initial_stiffness) * (trial_strain - plastic_strain); // 6
 
-    vec principal_stress;    // 3
-    mat principal_direction; // 3x3
+    vec3 principal_stress;     // 3
+    mat33 principal_direction; // 3x3
     if(!eig_sym(principal_stress, principal_direction, tensor::stress::to_tensor(trial_stress), "std")) return SUANPAN_FAIL;
 
     const auto trans = transform::compute_jacobian_nominal_to_principal(principal_direction);
 
     const auto s = tensor::dev(trial_stress);    // 6
     const auto norm_s = tensor::stress::norm(s); // 1
-    vec n = s / norm_s;                          // 6
+    vec6 n = s / norm_s;                         // 6
     if(!n.is_finite()) n.zeros();
 
     const auto ps = tensor::dev(principal_stress); // 3
-    const vec pn = normalise(ps);                  // 3
+    const vec3 pn = normalise(ps);                 // 3
 
-    const vec dsigmadlambda = -double_shear * pn - three_alpha_p_bulk; // 6
+    const vec3 dsigmadlambda = -double_shear * pn - three_alpha_p_bulk; // 3
 
     const auto dgdsigma_t = (pn(2) + alpha_p) / g_t;
     const auto dgdsigma_c = (pn(0) + alpha_p) / g_c;
@@ -94,8 +94,8 @@ int NonlinearCDP::update_trial_status(const vec& t_strain) {
 
     const auto const_yield = alpha * accu(principal_stress) + root_three_two * norm_s;
 
-    vec residual(3), incre;
-    mat jacobian(3, 3, fill::zeros);
+    vec3 residual, incre;
+    mat33 jacobian(fill::zeros);
 
     podarray<double> t_para, c_para;
 
@@ -113,7 +113,7 @@ int NonlinearCDP::update_trial_status(const vec& t_strain) {
         t_para = compute_tension_backbone(kappa_t);
         c_para = compute_compression_backbone(kappa_c);
 
-        const auto tension_flag = max_stress > 0.;
+        const auto tension_flag = max_stress > datum::eps;
 
         beta = -one_minus_alpha * c_para(2) / t_para(2) - alpha - 1.;