## 2 Background  
Limit states are those situations for which, if exceeded, the building may be considered as not meeting any of the structural requirements for which it was designed. In the case of the ultimate limit states, they are those that in the case of being exceeded, constitute a risk for people, because they produce the rupture of some structural elements, and with it the total or partial collapse of the building [2]. The finite element method (FEM) is a widespread numerical method for solving structural analysis models, dividing the system into smaller, simpler elements, and modeling each element with equations that describe its mechanical behavior. The calibration process involves comparing the output of the simulation with experimental data obtained from physical testing, and adjusting the model parameters until a satisfactory match is achieved. Current software suites provide calibrated FEM models that reproduce structural performance of steel connections as well as the interaction between elements in a realistic manner [3; 4]. Research has recently been conducted on evaluating the performance of bolted connection steel plates applying the FEM and the discontinuity layout optimization (DLO) [5]. The interactions between all the structural parts involved in a bolted connection are easier to model when using the FEM. In addition, the FEM provides information on displacements and stresses distribution prior to collapse. In turn, two commonly used possibilities to analyze the structural behavior of steel joints are solid and shell FEMs. For example, solid FEMs require more computational effort while providing more accurate modeling of bending moment resistance in steel joints [6]. Thanks to the use of the FEM, it is possible to optimize structural design as well as to develop reliable structural solutions for frames and connections between members [7]. Different types of joints have been tested, particularly T-joints and plate connections have been extensively studied using FEMs [3; 4; 8]. Shell elements have been used to simulate laminates in 2D FEM single-lap joints, improving the simulation of the stiffness of bolts and laminates as well as the model's ability to simulate the secondary bending [9]. The FEM provides valuable information about the interaction between the elements that make up the joint. A literature review shows that traditional design methods, which assume a rectangular stress block in plates, may inaccurately represent stress distribution under base plates, especially with thicker plates, leading to potentially non-conservative designs [10]. An adequate arrangement of the bolts improves stress distribution in connection plates [11]. Thin plates can benefit from the clamping force generated during the rivet installation process, which creates a localized compressive stress that helps to prevent the initiation and propagation of cracks. However, this positive effect diminishes as the thickness of the material increases [12]. Modeling of composite bolted joints recently incorporated friction, bolt-hole clearance, bearing damage, and joint failure [13]. Composite bolted joints can be modeled through a collection of components replicating the elastic properties of the bolt as demonstrated by [PERSON] et al. [14]. A beam model simulated the structural behavior of the bolt shaft while a nonlinear spring was employed to represent the frictional force between the plates, accounting for bolt-hole clearance, allowing the calculation of the displacement causedby the contact between the bolt shaft and the plate holes. The deformation of the plate holes was modeled by considering a beam resting on an elastic foundation. Additionally, a second spring component was utilized to account for the rotational stiffness linking the bolt head and shaft, as well as the elastic support provided by the plates to the bolt head.