## 1 Introduction
Geometric nonlinearity allows for more accurate modeling of laminates under complex loading conditions, enabling better prediction of load paths and resulting deformations, thus ensuring more realistic simulations [19]. Consequently, several researchers have incorporated geometric nonlinearity in static analyses of composite laminates, employing various theories: classical plate theory [20], higher-order theory [21; 22; 23; 24; 25], first-order shear deformation theory [26; 27; 28], hierarchical finite element method (HFEM) [29], solid shell models [30], higher-order refined zigzag theory [31], and layer-wise theory [32]. The key observations from these studies regarding geometric nonlinearity in composite laminates are as follows:  
* Geometric nonlinearity is crucial for large deformation problems in composite laminates, as it significantly affects stress distribution, load-carrying capacity, and deflection. * Geometric nonlinearities have been modeled using either Von Karman-type strains or Green-Lagrange-type strains. * Higher-order models are often necessary to capture nonlinear effects accurately, even for thin composites. * Geometric nonlinearity plays a significant role in accurately predicting the reliability, safety, and performance of composite structures. Therefore, incorporating geometric nonlinearity is essential for accurately predicting the behavior of undamaged composite laminates. However, all the aforementioned research focuses on undamaged laminates. The presence of delamination adds complexity to stress distributions and load paths compared to undamaged laminates. Thus, incorporating geometric nonlinearity into the model can provide more realistic numerical simulations of delamination in composite laminates. [PERSON] [33] developed a generalized multi-length scale composite plate theory that incorporates geometric nonlinearities to predict delamination behavior accurately under bending. [PERSON] et al. (2018) included geometric nonlinearity in FE models of delaminated laminates to capture delamination growth under static loads. [PERSON] et al. (2018) conducted a large-deflection bending study for CFRP laminates with multiple delaminations using cohesive zone elements. [PERSON] (2018) developed a layer-wise theory-based model to study the static response and delamination behavior of composite shell panels, capturing interfacial slipping and opening with high accuracy. [PERSON] et al. (2018) developed a floating node method-based model to perform geometrically nonlinear analysis of laminated composites, effectively capturing matrix cracking and delamination under large deformations, such as buckling and impact conditions. [PERSON] et al. (2018) developed a higher-order computational model incorporating Green-Lagrange nonlinear strain to predict the nonlinear deflection of composite structures with delamination and cracks, validated through experimental data. From this body of literature, the following key observations emerge:  
* There are only a few studies available that examine the effect of geometric nonlinearity on the static response of delaminated composite laminates under large deformation. * The existing literature has demonstrated the importance of incorporating geometric nonlinearity in models to predict delamination behavior more realistically. * Ignoring the effect of geometric nonlinearity may lead to the underestimation of delamination progression and its impact on the overall stiffness and stability of composite structures. The objective of this study is to develop a fast and robust numerical model to predict the static response of composite laminates with single and multiple interface delaminations while incorporating geometric nonlinearity. Building on the 3D degenerated element-based model developed by [PERSON] et al. (2018), this model has been extended to include the effects of geometric nonlinearity using Green-Lagrange strains.