Investigation of plastic hinge length in ductile shear walls in terms of various parameters

Reinfored concrete (RC) shear walls are element with significant lateral stiffness by their dimensions. In addition to the stiffness, the RC shear wall must to behaviour as ductile as possible depending on the height/ width ratio during the earthquake and ıt is requested to absorb the eartquake force which must be receive by forming plastic deformation. Special design is made in the critical area of the shear wall which will occur of plastic damage during the earthquake. With this shear wall design, it is aimed to avoid shear damage and to provide sufficient ductility. The determination of the plastic hinge length in accordance with the actual structure behaviour of the RC structural elements is very important in terms of ensuring that the account and the acceptantes to be made are in harmony with the actual behaviour. The plasticization mechanism and plastic hinge length of the vertical bearing elements such as reinforced concrete shear walls, which are very dominant in the construction behavior during the earthquake, are extremely important for the evaluation of the building performance. In this thesis, the hinging regions (hinge lengths) of the reinforced concrete walls were analytically determined in terms of various parameters effective on the behavior of the walls. Since the subject discussed in this study is plastic hinge, the nonlinear behavior of the modeled shear walls is examined. Examinations were made using ABAQUS program. In this study, 72 cantilever shear walls with different parameters were analyzed. The plastic length at the base of the RC shear wall models was determined on the basis of analysis results that depend on several parameters, such as the length / height ratio, axial load level and the ratio of the web horizontal reinforcement. As a result of the analysis, load-displacement graphs were obtained. In these graphs, 3 boundary situations are taken into consideration. This boundary conditions; Limit state at the time the maximum load is reduced by %15 and Turkish Earthquake Code 2007 (TEC 2007) with Turkish Building Earthquake Code 2018 (TBEC- 2018) permissible maximum displacement limits. According to these limits, the analytical plastic hinge lengths (Lpz) determined according to the yield situation in the longitudinal reinforcement especially at the shear wall ends and the visible plastic hinge lengths (Lp) according to the crushing situation at concrete in the pressure zone were determined separately. The findings were compared with the empirical formulas given in the literature to determine the plastic hing length of the shear walls. Displacement ductility values of the shear walls were also investigated. In the results of working; It has been observed that as the length / height ratio increases, plastic hinge lengths. It is observed that there is a relationship between analytical plastic hinge length and visible plastic hinge length values in the range of 0.15-0.50. Among the empirical formulas in the literature, the highest affinity was found to be 78% for apparent plastic hinge length and 69% for analytical hinge length according to the equation proposed by Kazaz. When the ductility values of the shear walls were examined, the results confirming the design conditions of TBEC -2018 were obtained. Keywords: Earthquake, Displacement, Plastic Hinge, Finite Elements, Reinforced Concrete Shear Wall.