## 6 Discussion on the Results  
Hysteretic behavior encompasses various forms of structural damage, such as slip or shear cracks in joints, bond failure in reinforcing materials, and shear failure in beams. This behavior is characterized by the fact that the restoring forces rely solely on the relative displacement. The force-displacement curve exhibits a steeper incline during tension compared to compression, with distinct and well-defined corner and yield points. Additionally, this behavior is marked by a degradation of stiffness following a sudden decrease in strength. Substandard RC structures usually feature a number of defects such as inadequate detailing of reinforcement, poor material qualities, poor quality control in construction and emphasis on strength rather than ductility of structures. These deficiencies lead to formation of a complex mode of failure with yield plateau, energy dissipation capability, and large deformation demands of the system. Elucidation of behavior of such structures requires some understanding of their energy dissipation capability and their deformation demands. Hysteretic behavior has long been recognized as a confusing aspect of structural performance because it might lead to nonlinear and unexpected response of structural systems subjected to severe cyclic loads, such as earthquakes [68]. Hysteresis in force-deformation response represents energy dissipation during loading and unloading cycles. This phenomenon is of vital importance to seismic behavior and response of structures and should be validated with experimental tests. Over the years, numerous experimental studies have been conducted to investigate how substandard RC components behave under cyclic and seismic loading. These tests--ranging from individual element tests (beams, columns, joints) to full-scale frame tests--have provided invaluable insights and data on hysteretic degradation in non-ductile RC structures. A notable illustration of the deficiencies in seismic design is presented by the research conducted by [PERSON], [PERSON], and [PERSON] [69]. They executed simulated seismic loading assessments on both interior and exterior beam-column joint configurations that featured inadequate reinforcing details characteristic of older construction practices, such as the absence of transverse reinforcement within the joint core and insufficient anchorage of beam bars. When subjected to cyclic lateral loads, these joints displayed limited strength and ductility, with the external joints particularly prone to joint shear failures and substantial loss of strength after only a few drift cycles. This groundbreaking study highlighted the susceptibility of inadequately detailed joints and emphasized the necessity for retrofitting interventions, noting improvements in performance when some joints were retrofitted with fiber-reinforced polymer (FRP) wraps. More contemporaneous research has continued to underscore these vulnerabilities. [PERSON] et al. [67] performed tests on four exterior beam-column joint subassemblies designed to replicate the detailing prevalent in reinforced concrete structures built prior to the 1970s. The specimens, examined in their original (unretrofitted) condition, displayed inadequate hysteresis behavior, indicative of brittle failure mechanisms. Among them, \begin{table}
\begin{tabular}{l c} \hline
**Reference** & **Experimental Value (MPa)** \\ \hline [PERSON] et al. [67] & 5.0 \\ [PERSON] et al. [8] & \(\sim\)5.0 \\ [PERSON] and [PERSON] [30] & 5.1 \\ [PERSON] et al. [10] & \(\sim\)5.1 \\ \hline \end{tabular}
\end{table} 
Table 4: Critical shear stress at joint Comparison of Experimental Data with Model Predictions. two joints were subject to joint shear failures, while the other two experienced anchorage pullout of beam bars, aligning with the expected deficiencies of their designs. The authors noted that \"all specimens exhibited poor hysteresis behavior dominated by catastrophic damages of brittle nature\".