This work presents finite element (FE) modeling using the ABAQUS program to investigate the effect of steel reinforcement with three different types of high-strength steels, grades 420, A1035, and SD685 on the flexural behavior of RC beams under monotonic loading. Experimental findings from the literature have been used to validate the proposed model. The numerical load, deflection, mode of failure, failure concrete strain, and bottom steel strain at failure of 24 numerical specimens with collapsed conditions of tension-controlled, balanced, and compression-controlled are recorded. Also, the effect of compression reinforcement is being investigated. The results reveal that the flexural behavior of the experimental test for the three steel grades is well validated by FE analysis. The ductile and brittle behavior features of yield strength (YS) larger than 420 can be predicted for specimens designed according to current standards ACI-318M-19. Also, the compression reinforcement improves load capacity while reducing displacement. It may be argued that when YS decreases, tensile stress and strain of flexural rebar rise, causing the beam to become more ductile. When the YS increased, the brittle behavior was induced.

The purpose of this study is to explore the numerical behavior of circular RC short columns with different degrees of confinement with CFRP (0%, 25%, 50%, and 100%) wraps under concentric and eccentric loading. The numerical analysis carried out by using an improved concrete plastic-damage model (CDPM) implemented in ABAQUS software for finite element (FE) analysis. The FE model simulated a total of twenty-four numerical specimens. The findings were matched to published experimental test results in the literature. The findings of the FE model and the experimental data were good similar. As a consequence, the model was found to be valid. The numerical results shows that as load eccentricity increased, the load carrying capacity of columns decreased for unconfined specimens, whereas the decline in strength for confined specimens becomes limited as the degrees of confinement ratio increased. In addition, increasing the CFRP confinement ratio improves the column's load-bearing capability at the same load eccentricity.

The beam-column joints play an important role in the structures where the functions of connection shortage by transport the forces like shear, moment, and torsion from the beam to the column. So, this study represents an attempt to investigate the performance and the effect of limited cycles of repeated load on the strength of the exterior beam-column joint core. Therefore, 34 specimens have been investigated by using a numerical analysis that used the finite element method. To simulate these specimens, the concrete damage plasticity model was used to define the concrete materials and the nonlinear isotropic/kinematic (combined) hardening model for steel material definition. These models are involved in the ABAQUS software package, version 2020. This study involves key parametric studies on beam-column joints, which are summarized as changing the ratio of shear reinforcement of the joint core in addition to using two types of shear reinforcement. This study also includes the effect of flexural reinforcement of the beam as well as the beam’s shear reinforcement effect on the strength of the beam-column joint. To calibrate the software to simulate a realistic result, three specimens have been used, which have been tested in previous studies. It has been found that this numerical model accurately predicts the experimental response under limited cycles of repeated loading. The ultimate load from modelling was compared with the experiment once, having a difference of less than 10% and the ultimate displacement having a difference of less than 11%. It has been found that increasing the ratio of the joint’s shear reinforcement to double has no significant effect on the ultimate load. Otherwise, decreasing it to half leads to a decrease in the ultimate load compared with a specimen that is designed according to ASCE352-02R. This study has studied the effectiveness of increasing the shear reinforcement by adding an x-shape reinforcement. Also, the flexural reinforcement of the beam has found it has increased the ultimate load capacity by 48% Where the ratio of flexural reinforcement increased to 1.8%, the load bearing capacity was enhanced.

In many seismically active regions worldwide, massive reinforced concrete (RC) structures built before the 1970s existed. These older RC buildings, in countries having seismic history, were designed for gravity loads only. Anyway, the beam-column connections influence the structures where the functions of connection shortage by transport the forces like shear, moment, and torsion through the beam to the column. Also, it could behave in a ductile manner to help the structure resist the seismic, as simulate the seismic loading by high and low cyclic loading. Due to the failure of external joints more than the internal beam-column joints, this review focuses on the behavior of exterior beam-column joints under cyclic loading, consequently simulated the behavior under an earthquake and the reinforcement detailed.

In this study a numerical examples and solutions has been obtained by using three system of beam resting on elastic foundation (BOEF) which was adopted previously by three different engineering software. The first part of this paper was related to verify the model of (BOEF) by using ETABS2015 by make a comparison with previous results by determination the maximum settlements at the mid of span which show a good agreement between ETABS2015 and other results, where the total differences was vary from 2.13 % to 3.27%. . The second part of this study was highlighted on the settlement of BOEF with different parametric study (beam thickness, soil subgrade reaction(K S ) and the load location), case (1) was selected for this goal. In this paper it is found that the differential settlement along the beam are decrease as increasing in the beam stiffness in addition to possibility to obtain uplift (positive settlement ) for some type of changing in the load location specially for higher thick beam . It was noticed that the settlement are increased significantly as reducing in the (K S ). Finally this study show a different form of deflection by combination two of parametric study.