# Safety Performance Evaluation of Ultra-High-Performance Concrete Semi-Assembled Barrier
## 3 Collision Simulation System
### Vehicle Finite Element Modeling  
According to the relevant requirements of the Standard for Safety Performance Evaluation of Highway Barriers (JTG B05-01-2013) for vehicles, the SB-level collision test requires real vehicle collisions of a 1.5-ton car, 10-ton bus, and 18-ton truck. The relevant parameters and collision requirements of the three models are listed in Table 4. The collision points of the vehicle were located at one-third of the starting point of the barrier along the driving direction.  
In this study, simulation models of the three types of vehicles were established. The three vehicle models all use a section shell to simulate the vehicle body and a section solid to simulate the engine and tire. MAT-ELASTIC (MAT-1), MAT-PIECEWISE-LINEAR-PLASTICITY (MAT-24), and MAT-RIGID (MAT-20) were used to simulate the material of the vehicles. The keywords _Spot Wold_, _Rigid-Body_, and _Extra Nodes Set_ connected the vehicle components.  
To ensure the reliability and effectiveness of the vehicle model used in the collision simulation analysis, the selected vehicle finite element model was verified using a frontal collision test before the collision analysis. A rigid wall was set 20 cm from the front of the vehicle bumper, and the vehicle impacted the rigid wall vertically at a speed of 50 km/h. The rigid wall simulates the ground and the rigid wall being collided [38]. Figure 3 shows the finite element frontal collision experiment diagram and energy change curve of the three models. The deformation of the vehicle components during the collision process was reasonable, and no element distortion or penetration occurred. The collision effect in the simulation experiment was reasonable. After analysis of the three models, the hourglass energy of the collision model was 4%, 2%, and 4% of the initial total energy of the system, respectively, which was less than 5% of the total energy. Therefore, the frontal collision test simulation results were reliable, and the vehicle model could be used for further simulation analyses.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Type**} & **Weight** & **Length** & **Width** & **Height** (mm) & **Angle (\({}^{\circ}\))** & **Velocity** (km/h) \\ \hline Car & 1.5 & 4600 & 1770 & 1430 & 20 & 100 \\ Bus & 10 & 9000 & 2450 & 3360 & 20 & 80 \\ Truck & 18 & 11,300 & 2500 & 3500 & 20 & 60 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Vehicle model parameters.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Component** & \(\rho\)**(/g/cm\({}^{3}\))** & \(G\) **(GPa)** & \(A\) & \(B\) & \(C\) & \(N\) & \(F_{C}\) **(MPa)** \\ \hline UHPC & 2.54 & 32.64 & 0.25 & 2.49 & 0.007 & 1.08 & 142.48 \\ C30 & 2.40 & 12.5 & 0.28 & 1.85 & 0.007 & 0.84 & 30.9 \\ Component & \(T\) (MPa) & _EPS0_ & _EFMIN_ & \(SF_{max}\) & \(P_{C}\) (MPa) & \(U_{C}\) & \(P_{L}\) (MPa) \\ UHPC & 9.81 & \(1\times 10^{6}\) & 0.016 & 7.0 & 47.49 & 0.00187 & 1000 \\ C30 & 3.00 & \(1\times 10^{6}\) & 0.01 & 7.0 & 10.00 & 0.0011 & 1210 \\ Component & \(U_{L}\) & \(D_{1}\) & \(D_{2}\) & \(K_{1}\) (GPa) & \(K_{2}\) (GPa) & \(K_{3}\) (GPa) & \(FS\) \\ UHPC & 0.068 & 0.061 & 1.0 & 85 & \(-\)171 & 208 & 0 \\ C30 & 0.16 & 0.04 & 1.0 & 12 & 135 & 698 & 0 \\ \hline \hline \end{tabular}
\end{table}
Table 3: HJC parameters of UHPC and NC.