## 3 Damage Evaluation Model for FSCMR Wall Panel Structure
As \(\delta/\delta_{y}\) increases to a range of 2 to 4.5, the specimens begin to crack slightly. At this stage of mid-term development, the damage index falls between 0.25 and 0.4. At the next stage (that is, the stage of rapid development), aggravated damage begins to occur. Here, \(\delta/\delta_{y}\) tends to stay between 4.5 and 6, while the damage index fluctuates within a range of 0.4 to 0.7. As the experiments continue, the specimens are completely destroyed and have no bearing capacity. Here, the corresponding damage index varies between 0.7 and 1.0. Backed by different damage models, researchers in the field carried out a large number of experiments to study the force bearing performance of the structures and their members [26; 27]. The results clarify the limits of the damage index at different damage stages, where damage that occurs to a reinforced concrete structure under seismic influences is divided into five levels: fairly good, slightly damaged, moderately damaged, severely damaged, and collapsed (see Table 2). Figure 8: Comparative diagram of damage indexes between two FSCMR wall panel structures. Figure 7: Relationship curves of damage index and \(\delta/\delta y\). From Table 2, it can be concluded that, compared to a reinforced concrete structure, an FSCMR wall panel structure at any stage of failure generally has a higher damage index. In other words, the deformation of the grid and block largely absorb any seismic energy, meaning that the FSCMR wall panel structure overall performs fairly well in terms of collapse resistance. The study, with the help of OpenSees, simulates the hysteresis of an FSCMR wall panel structure under cyclic loading. The simulated results are then compared with collected experimental data (see Figure 9). The accuracy of the model can be verified by examining whether or not the hysteretic curve and skeleton curve coincide. Here, MX-1 is used to specify the procedure. The research team introduces OpenSees in its simulation of specimen physical performance (see Figure 10), using the material-specialized model Concrete02, in which the strength and linear emollescence in tension of concrete is applied in the study of the constitutive relationship of concrete. In contrast, in the uniaxial material model, a hysteretic material is chosen for the simulation of reinforced concrete, as the model does not eliminate stiffness degradation upon the lift of force impulsion and is fully able to reflect the pinching effect. The beam-column unit makes use of the nonlinear fibre model provided in the OpenSees simulation. In accordance with the equivalent principle of compressive stiffness and bending stiffness, the paper simulates the reinforced concrete plate in the ShellMITC4 unit, which is defined as a multi-layered shell element. It can be concluded that the simulated results of both hysteretic curves and skeleton curves with the help of OpenSees stay consistent with the corresponding data collected from the experiment. The study simulates the cyclic loading test by altering concrete strength, calculating the displacement item \(\delta_{m}/\delta_{u}\) and energy item \(\int\!dE/\mathrm{Q}_{y}\) (\(\delta_{u}-\delta_{y}\)) accordingly. From these results, Equation (5) is used to obtain the damage indices at each stage of force impulsion, which are then compared with the experimental data for MX-1 (of concrete C30). \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Structure** & **Fairly Good** & **Slightly** & **Moderately** & **Severely Damaged** \\
**Conditions** & **Fairly Good** & **Damaged** & **Damaged** & **and Collapsed** \\ \hline Park & 0–0.1 & 0.1–0.25 & 0.25–0.4 & 0.4–1 \\ Hindi & 0–0.1 & 0.1–0.2 & 0.2–0.6 & 0.6–1 \\ Ghobarah & & 0–0.15 & 0.15–0.3 & 0.3–1 \\ HU Yuxian & & 0–0.15 & 0.2–0.4 & 0.4–1 \\ NIU Ditao & 0–0.2 & 0.2–0.4 & 0.4–0.65 & 0.65–1 \\ Liu Boquan & 0–0.1 & 0.1–0.3 & 0.3–0.6 & 0.6–1 \\ Wang & 0–0.2 & 0.2–0.4 & 0.4–0.6 & 0.6–1 \\ Guangyuan & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Damage index scopes at different failure stages.