## 3 Results and Discussion
### Parametric Study
#### 3.2.1 Single Interface Delamination
However, in the case of the cross-ply laminate with corner damage of size \(0.5a\), the nonlinearity is least affected compared to the other two damage sizes for the CFFF boundary condition. There is no significant effect of nonlinearity on damage size for the SSSS boundary condition (Figure 8f) with corner damage or for the  
Figure 6: Maximum nonlinear deflection of composite plates of various boundary conditions, lamina sequences, and delamination locations with delamination size of a/5. (**a**) Maximum nonlinear deflection for SSSS and CFFF boundary conditions with delamination at center. (**b**) Maximum nonlinear deflection for CCCC and CSCS boundary conditions with delamination at center. (**c**) Maximum nonlinear deflection for SSSS and CFFF boundary conditions with delamination at edge. (**d**) Maximum nonlinear deflection for CCCC and CSCS boundary conditions with delamination at edge. (**e**) Maximum nonlinear deflection for SSSS and CFFF boundary conditions with delamination at corner. (**f**) Maximum nonlinear deflection for CCCC and CSCS boundary conditions with delamination at corner. CFFF boundary condition with center damage (Figure 8b). No significant effects of damage location (center, edge, corner) on nonlinearity have been observed. The effect of nonlinearity on delamination size for the symmetric angle-ply laminate has been plotted in terms of percentage changes in maximum deflection vs. load in Figure 9a,b, Figure 9c,d, and Figure 9e,f for damage located at the center, edge, and corner, respectively. In all cases, it is found that the larger the damage size, the greater the effect of nonlinearity. No significant effects of damage location (center, edge, corner) on nonlinearity have been observed. Figure 7: Maximum nonlinear deflection of composite plates of various boundary conditions, lamina sequences, and delamination locations with delamination size of a/2. (**a**) Maximum nonlinear deflection for SSSS and CFFF boundary conditions with delamination at center. (**b**) Maximum nonlinear deflection for CCCC and CSCS boundary conditions with delamination at center. (**c**) Maximum nonlinear deflection for SSSS and CFFF boundary conditions with delamination at edge. (**d**) Maximum nonlinear deflection for CCCC and CSCS boundary conditions with delamination at edge. (**e**) Maximum nonlinear deflection for SSSS and CFFF boundary conditions with delamination at corner. (**f**) Maximum nonlinear deflection for CCCC and CSCS boundary conditions with delamination at corner. The effect of nonlinearity on delamination size for the anti-symmetric angle-ply laminate has been plotted in terms of percentage changes in maximum deflection vs. load in Figure 10a,b, Figure 10c,d, and Figure 10e,f for damage located at the center, edge, and corner, respectively. In most cases, apart from a few exceptions, it is found that the larger the damage size, the greater the effect of nonlinearity. In the case of delamination located at the center, there is not much effect of nonlinearity on delamination size for the SSSS boundary condition (Figure 10a). A similar observation can be made for corner delamination under the CFFF boundary condition (Figure 10e). No significant effects of damage location (center, edge, corner) on nonlinearity have been observed. Figure 8: % Difference between linear and nonlinear maximum deflection for \((0/90/0)_{3S}\) lamina sequence and various boundary conditions, delamination location and size. (**a**) % Difference for CCCC and CSCS boundary conditions with delamination at center. (**b**) % Difference for SSSS and CFFF boundary conditions with delamination at center. (**c**) % Difference for CCCC and CSCS boundary conditions with delamination at edge. (**d**) % Difference for SSSS and CFFF boundary conditions with delamination at edge. (**e**) % Difference for CCCC and CSCS boundary conditions with delamination at corner. (**f**) % Difference for SSSS and CFFF boundary conditions with delamination at corner.