## 3 Damage Evaluation Model for FSCMR Wall Panel Structure  
Because of experiments conducted on a large number of reinforced concrete beams and columns, [PERSON], [PERSON], and [PERSON] et al. [18] created a seismic damage model that depicts the linear superposition of maximum deformation and accumulative energy consumption. The damage index, \(DI_{p}\), is defined as follows:  
\[DI_{p}=\frac{\delta_{m}}{\delta_{u}}+\beta\frac{\int dE}{Q_{y}\delta_{u}}. \tag{1}\]  
The model itself is built on the pre-conditions that  
1. the interrelation between maximum deformation and accumulative hysteretic energy is not considered; and
2. the contribution of maximum deformation and accumulative hysteretic energy to damage follows a linear pattern. Backed by extensive experimental evidence, the model stands as a well-integrated damage model that considers the effects of damage-induced stiffness degradation, strength degradation, and adhesive sliding on the overall structure. It must be noted that the model introduces the ratio of accumulative hysteretic energy to the product of yield strength and the displacement limit, in order to evaluate the contribution of accumulative hysteretic energy to damage indices. However, in a physical sense, the obtained results are hardly sensible; and, given the under-developed calculation theories, the damage indices fall below accuracy limits. In this context, this paper introduces [18], and modifies the double-parameter Park-Ang damage model [19; 20] in order to analyse and evaluate the damage performance of an FSCMR wall panel structure in the process of energy consumption and seismic mitigation, which is carried out as follows:  
1. The modification is conducted under the assumption that the linear superposition of maximum deformation and accumulative hysteretic energy of the Park-Ang model remains unchanged. Under such conditions, the product of the yield strength and the displacement limit in the denominator is replaced by the plastic energy consumption under monotone loading, which has proven to be more physically realistic. The simplified recoverability model for an elastic-plastic structure under ideal conditions is applied to calculate the plastic capacity of energy consumption under monotone loading, which, as Figure 6 shows, equals the envelope area. The Park-Ang model is then adjusted accordingly:  
\[DI_{P}=\frac{\delta_{m}}{\delta_{u}}+\beta\frac{\int dE}{Q_{y}(\delta_{u}- \delta_{y})}. \tag{2}\]  
The variables in this equation represent the following quantities:  
Figure 6: Calculation diagram for plastic energy consumption. \(Q_{y}\) (\(\delta_{u}-\delta_{y}\)) is the energy consumption at the limits of the ideal elastic-plastic system under monotone loading;  
\(Q_{y}\) is the structural strength at the yielding point;  
\(\delta_{y}\), \(\delta_{u}\), \(\delta_{m}\) are the yielding deformation, deformation limit, and maximum deformation;  
\(\int\!dE\) is the accumulative hysteretic energy of the structure (to the point under calculation);  
\(\beta\) is the weight coefficient of the accumulative hysteretic energy item. \(\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\! \!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\  
After the data from all three damage models are collected, the relationship between the damage index and the displacement ratio (or \(\delta/\delta_{y}\)) can be determined (see Figure 7). As shown in the figure above, the damage indices calculated by the modified Park-Ang model tend to fall between those of the other two models, which is consistent with the experimental results of the paper. Comparatively, it better depicts the failure processes and damage patterns of FSCMR wall panel structures. Figure 8 shows damage indices for the two specimens. Figure 8 shows that the two specimens share a relatively similar variation pattern. As \(\delta/\delta_{y}\) fluctuates between 0 and 2, the specimens maintain fairly good conditions, with no visible damage on the surface. At this point, the damage index varies between 0 and 0.25.