## 1 Introduction  
The seismic design of structures requires reliable estimation of the behavior of the components that are expected to resist the lateral load. Premature failure of any such components below the design load or ductility demand will change the structural performance level. In the case of a special concentrically braced frame (SCBF) system, the brace components act as a fuse element, dissipating the earthquake energy and minimizing the damage to the gravity-resisting elements. Braces are designed to accumulate inelastic deformation due to the buckling and yielding under cyclic axial loading in the event of earthquakes. The primary mode of failure for the SCBF system during the seismic event is fracture at the middle of the brace members for its optimum performance. Past earthquakes, e.g., the 2011 Christchurch Earthquake, the 1995 Kobe Earthquake, the 1994 Northridge Earthquake, and the 1985 Mexico City Earthquake, have shown that brace frame systems are susceptible to premature failure. The various undesirable failure modes observed are fracture of interface weld of gusset plate, tearing of gusset plate, buckling of gusset plate, net section failure of brace cross-section, premature failure of brace section, and block shear failure of brace or gusset plate [1; 2; 3; 4; 5; 6; 7; 8]. Because most of the steel-braced frames were constructed before the incorporation of the ductility-based design concepts, failure modes are mostly related to lower brace strengths and limited ductility capacity. Recent studies conducted in the United States and Canada have also highlighted these deficiencies and their consequences for the overall seismic performance of these systems [9; 10]. The connections of these lateral load resistance systems are the most critical components of the structure because of the associated complexity involved in designing and detailing the connection to withstand large inelastic drift without undergoing premature fracture. The concentrically braced frame (CBF) system is the most prominent lateral load-resisting system, used widely because of the ease of constructability, low cost, and high strength-to-weight ratio. The CBF system designed in high seismic zones to withstand large inelastic drift is called the special concentrically braced frame (SCBF) system. Research on the connection design for the SCBF system is not explicitly coded like that of the moment resistance frame [11]. This can be attributed to the complex stress state of the gusset plate, whose behavior is difficult to predict, as well as limited experimental studies compared to other connection types. Mostly, the design of these connections is based on empirical formula to predict their performance at lower inelasticity demand. However, the performance of these connections at higher lateral drift needs to be verified. [PERSON] [12] proposed a linear clearance of \(2t_{p}\) (\(t_{p}\) = thickness of gusset plate) in the tapered gusset plate to facilitate out-of-plane buckling of the brace member to dissipate higher energy and withstand higher drift. These types of braced systems are called out-of-plane buckling (OOPB) braced systems. Before that, the gusset plates were directly connected to the end connection and called direct connection (DC) braced systems. Research conducted by [PERSON] et al. [13] proposed the rectangular gusset plate with elliptical clearance. It is observed that by reducing the gusset plate's flexural rigidity, the braced frame's ductility can be increased. Predicting fracture ductility of brace specimens is the most important yardstick for the collapse assessment of special concentrically braced frames (SCBFs). Most empirical formulations have neglected the effects of end connections in quantifying brace performance. The knee-braced system (KBS) does not allow the brace members to buckle but provides energy dissipation with the help of the knee anchor yielding in flexure [14]. A recent experimental study on KBS observed stable hysteresis response and higher lateral drift capacity.