Buckling Of Bars Research Articles

Galaxy flybys: evolution of the bulge, disc, and spiral arms

ABSTRACT Galaxy flybys are as common as mergers in low-redshift Universe and are important for galaxy evolution as they involve the exchange of significant amounts of mass and energy. In this study, we investigate the effect of minor flybys on the bulges, discs, and spiral arms of Milky Way mass galaxies for two types of bulges – classical bulges and boxy/peanut pseudo-bulges. Our N-body simulations comprise of two disc galaxies of mass ratios 10:1 and 5:1, where the discs of the galaxies lie in their orbital plane and the pericentre distance is varied. We performed photometric and kinematic bulge–disc decomposition at regular time-steps and traced the evolution of the disc size, spiral structure, bulge sersic index, bulge mass, and bulge angular momentum. Our results show that the main effect on the discs is disc thickening, which is seen as the increase in the ratio of disc scale height to scale radius. The strength of the spiral structure A2/A0 shows small oscillations about the mean time-varying amplitude in the pseudo-bulge host galaxies. The flyby has no significant effect on non-rotating classical bulge, which shows that these bulges are extremely stable in galaxy interactions. However, the pseudo-bulges become dynamically hotter in flybys indicating that flybys may play an important role in accelerating the rate of secular evolution in disc galaxies. This effect on pseudo-bulges is a result of their rotating nature as part of the bar. Also, flybys do not affect the time and strength of bar buckling.

Experimental investigation on the effectiveness of lateral restrainers to the vertical steel in reinforced masonry walls under axial compression

Reinforced masonry (RM) walls are mostly used in low to mid rise residential/industrial buildings in cyclonic and seismic regions. They are conventionally constructed with grout embedded vertical steel reinforcements positioned in the middle of the hollow blocks. However, these reinforcing bars are rarely detailed with lateral restrainers, which are considered essential in the design standards to avoid buckling of the vertical bars. This research investigates the effectiveness of lateral restrainers to the axial compression resistance of RM by testing of 128 walls under concentric and eccentric compression with different reinforcement configurations. The tested walls (190 mm thick × 600 mm wide) consisted of various types of detailing with and without lateral restrainers, grout strengths (25–50 MPa), and three heights (800 mm, 1400 mm and 2400 mm). Two walls were constructed and tested for each configuration, out of which one was tested to determine the ultimate strength and the other tested to acquire ultimate strength, axial deformation of the wall, axial strain in the steel bars and strain on the surfaces of the face-shell. The experimental results revealed that the grout has significantly contributed to the axial capacity, whilst the lateral restrainer reinforcement detailing had no significant effect on either the steel strain development or on the overall strength of the RM walls. Under concentric compression, the strain measurements in the vertical steel bars indicated that irrespective of the absence or presence of the lateral restrainers, the vertical bars remained under compression throughout the loading history with no evidence of buckling. Effects of slenderness and eccentricity were also evaluated for the RM walls under compression. It can be concluded from this research that the RM walls designed and constructed without lateral restrainers to resist cyclonic and seismic forces need not be treated as unreinforced masonry (URM) for compression if the vertical bars are surrounded by well compacted grout.

Effects of tie detailing configurations on reinforcement buckling and seismic performance of high-strength RC columns

The premature buckling and subsequently low-cycle fatigue fracture of longitudinal bars is one of the main failure modes of reinforced concrete (RC) columns under earthquake loading. The use of high-strength steel bars (HSSB) in RC columns reduces rebar diameter or increases tie spacing, thus increases the vulnerability of bar buckling. In view of this, this paper studies the effects of transverse reinforcement detailing (referred hereafter also as ‘tie detailing’) configurations on reinforcement buckling and then on the seismic performance of high-strength RC columns. Five rectangular RC columns with different tie detailings and axial load ratios were tested under constant axial load and reversed horizontal load. All three tie detailings studied have the same large rectangle closed-hoop, while small hoops/ties are different: including two cross-ties (Type Ⅰ), a small rhombus closed-hoop (Type Ⅱ), or two small rectangle closed-hoops (Type Ⅲ). The axial load ratio includes 0.06 and 0.18. The anti-buckling constraint mechanisms of different tie detailings are proposed, and then the global buckling length of longitudinal bars in RC columns with different tie detailings are calculated. On this basis, the effects of tie detailing on bar buckling and on the seismic performance of RC columns are studied. The observed results of bar buckling verify the reliability of the proposed anti-buckling constraint mechanisms and reinforcement buckling length calculation model. Type Ⅲ tie detailing provide better anti-buckling constraint, and thus reduces buckling length of longitudinal bars of RC columns than that with Type Ⅰ & Type Ⅱ tie detailings. Meanwhile, the use of Type Ⅲ tie detailing enhances the seismic performance of RC columns (ultimate drift ratio and hysteretic dissipated energy) than that with Type Ⅰ & Type Ⅱ tie detailings. The effects of tie detailing on seismic performance of RC columns are more significant under high axial load ratio. As the longitudinal bars are more susceptible to buckle under high axial compression, thus Type Ⅲ tie detailing can more prominently play its advantages of delaying bar buckling and improving the seismic performance of RC columns.

Inelastic Responses and Finite Element Predictions of Fiber Cementitious Composite and Concrete Columns.

In this research, reinforced concrete (RC) and strain-hardening cementitious composite (SHCC) columns subjected to lateral loads combined with a constant load were investigated, both by experiments and predictions, with two distributed inelastic finite element models established by the stiffness and flexibility formulations. SHCC applied in the column plastic hinge region could not only enhance the lateral load and displacement capacities of columns but also offer effective advantages in the control of bending and shear cracks induced by multiple microcracks, the prevention of the spalling of cover concrete, and the resistance to buckling of steel bars. With the layered cross-sectional approach using constitutive laws of SHCC considering a proposed model of the post-cracked high-ductile tensile characteristics, as well as concrete and reinforcing steel bars, an inelastic beam-column finite element model was presented with a distributed flexibility formulation. In comparison with experiments concerning the RC and reinforced strain-hardening cementitious composite (R-SHCC) columns, the current flexibility method showed relatively accurate estimations in the lateral load and displacement responses of column systems as well as in localized nonlinear responses of cross-section as estimated in axial strains of longitudinal reinforcing steel bars. In comparison with the stiffness method, the current flexibility method gave more accurate solutions at both element and structural levels, as manifested in the experiments and analysis solutions.

Cyclic loading test for shear-deficient reinforced concrete exterior beam-column joints with high-strength bars

The seismic behavior of exterior beam-column joints is significantly affected by the beam rebar yield strength and joint hoop ratio. In the present study, high-strength bars were used for beam longitudinal bars and stirrups in exterior beam-column joints with the joint hoop ratio lower than the requirement of ACI 318–14. In an attempt to distribute the damage from the joint panel toward the beam in the shear deficient exterior beam-column joints, the beam shear resistance was intentionally decreased by removing the beam cross-ties or by using the high-strength beam stirrups at a large spacing. Cyclic loading tests were performed on 9 exterior beam-column joints. The test parameters were the amount of joint hoop bars, the yield strength and diameter of the beam longitudinal bars, the yield strength and spacing of the beam stirrups, and use of beam cross-ties. The test results showed that the seismic performance was improved by increasing the beam flexural damage, preventing a shear failure, through a reduced contribution of the beam stirrups to the shear strength of the beam or weakening the beam by removing the beam cross-ties that increased vulnerability of buckling of the beam longitudinal bars. As the damage concentration was transferred from the joint panel to the weakened beam, the energy dissipation capacity and damping ratio increased by 30% and 54%, respectively. It was found that 33% decrease in the amount of joint hoop bars compared to that of prescribed in ACI 318, equal to one leg of joint stirrup, was enough to change the failure mode from the beam flexural failure to severe joint shear failure. The allowable development length of beam compression bars was discussed to prevent the cover concrete spalling at the back face of the column. Particle image velocimetry (PIV) was conducted to accurately measure the joint shear deformation and the distribution of the local flexural deformation of the beam.

Material Characterization of GFRP Bars in Compression Using a New Test Method

Abstract This article presents a new test method for determining the mechanical properties of glass fiber–reinforced polymer (GFRP) composite bars in compression, namely the compressive strength, compressive modulus of elasticity, ultimate crushing strain, and compressive stress-strain curves of the bars. The contribution of GFRP bars in compression is currently neglected by major design guidelines related to GFRP-reinforced concrete columns. However, the demand for using GFRP bars is increasing because multiple researchers have shown the effectiveness of the bars in concrete columns. Thus, the need for characterization of the mechanical properties of GFRP bars is increasing, while there is no standardized test method to evaluate the compressive properties of these bars. Therefore, in this article, a new test method is proposed for evaluating the compressive characteristics of GFRP bars. The proposed test method was examined through testing a total of 35 specimens. It was observed that the test method was able to evaluate the compressive characteristics of the GFRP bars successfully. Three different modes of compressive failure were observed, which were related to the crushing of GFRP bars in different locations in the bar, but no premature failure or bar buckling was observed. Moreover, a comparison between tensile and compression characteristics of the GFRP bars showed that the tensile test results are not sufficient to estimate the compressive characteristics, and performing a compression test is necessary.

Experimental study on the effects of bi‐directional loading pattern on rectangular reinforced concrete walls

AbstractIn this experimental study, three identical reinforced concrete (RC) walls were tested under three different lateral loading patterns. These loading patterns were cyclic in‐plane, skewed with 45° angle and clover leaf. The main objective was to investigate the effects of these bi‐directional loading patterns on the seismic behavior of slender rectangular RC walls. The results showed significant increase in tensile and compressive strains in concrete and longitudinal bars that led to earlier cover concrete spalling and bar buckling in the specimens subjected to bi‐directional loading. The neutral axis depth and compression zone were found to be substantially larger when subjected to bi‐directional loading and this led to the occurrence of concrete crushing and bar buckling in the web. Moreover, lateral instability failure triggered earlier in the specimens under bi‐directional loading, as a result of reduction of out‐of‐plane stiffness of the wall. However, bi‐directional loading did not significantly increase out‐of‐plane buckling of the wall in terms of out‐of‐plane displacement. In‐plane and out‐of‐plane shear cracks formed in one of the specimens subjected to bi‐directional loading, whereas the same wall under in‐plane loading developed only flexural cracks. It was also found that in‐plane shear deformation was larger when the wall was subjected to bi‐directional loading. The results of this experimental study emphasize the need for further investigation of the effects of bi‐directional loading on RC structural walls.

A portable pen-sized instrumentation to measure stiffness of soft tissues in vivo

Quantitative assessment of soft tissue elasticity is crucial to a broad range of applications, such as biomechanical modeling, physiological monitoring, and tissue diseases diagnosing. However, the modulus measurement of soft tissues, particularly in vivo, has proved challenging since the instrument has to reach the site of soft tissue and be able to measure in a very short time. Here, we present a simple method to measure the elastic modulus of soft tissues on site by exploiting buckling of a long slender bar to quantify the applied force and a spherical indentation to extract the elastic modulus. The method is realized by developing a portable pen-sized instrument (EPen: Elastic modulus pen). The measurement accuracies are verified by independent modulus measures using commercial nanoindenter. Quantitative measurements of the elastic modulus of mouse pancreas, healthy and cancerous, surgically exposed but attached to the body further confirm the potential clinical utility of the EPen.

Multiscale Investigations of RC Shear Wall Buildings

ABSTRACT The precise description of reinforced concrete shear wall (RCSW) systems under severe dynamic loading remains a difficult research question owing to the intrinsically multi-scale underlying mechanisms, ranging from building’s irregularity to individual core walls, and even to the millimeter length-scales nonlinear shear over cracks and progressive steel bar buckling. This study adopted a parallel multiscale finite element analysis platform that can link the millimeter-level microphysical phenomena to the entire building-level dynamic responses in order to analyze weak pre-1980 buildings that lack modern codes such as boundary elements of walls. Results offer physically sound rationales behind the multi-scale damage behaviors.

Comparison of Damage Models of Reinforced Concrete Columns and Research on Improved Stiffness Model

Based on the test data of reinforced concrete (RC) columns published in Pacific Earthquake Engineering Research Center (PEER) database, three existing typical seismic damage models are studied, and the distribution law of damage index of the same member calculated by energy dissipation model, stiffness degradation model and Park-Ang model are summarized. The relative stiffness with the yield stiffness as the reference is constructed, and the stiffness model is improved to solve the problems that the original stiffness model is too sensitive to the initial damage and the calculation accuracy is not high. The data show that the new model has high accuracy in calculating the damage index of components under earthquake. Comparing the damage index calculated by the model with the apparent damage phenomenon of each stage of the specimen, and comparing the damage development index of different models, it is found that the stiffness model is the most accurate to evaluate the damage. The damage grade evaluation standard based on stiffness degradation is proposed, and the damage indexes under three different damage states of Concrete Cracking, Significant Concrete Spalling and Long Bar Buckling are analyzed. The results show that the damage index calculated by the damage assessment method based on stiffness degradation has good correlation under different damage states.

The nonclassical problem of the compressed bar stability

The non-classical problem of the stability loss of a straight vertical bar with elastic flexible elements at the ends is considered. The mathematical model for the study of stability loss consists of a linearized differential equation for buckling of a constant cross section bar, supplemented by boundary conditions. Critical force is determined by analytical and numerical methods. Two versions of computational algorithms are presented. For one design scheme of the rod in the Matlab computing environment, the critical forces are calculated using two methods. The found critical forces differ insignificantly, which confirms the reliability and efficiency of the proposed algorithms.

Experimental and numerical investigations on seismic performance of RC bridge piers considering buckling and low-cycle fatigue of high-strength steel bars

In order to promote the application of high-strength steel bars (HSSB) in reinforced concrete (RC) bridge structures, the mechanical properties of HSSB as well as seismic performance of high-strength RC piers were investigated by experimental study and numerical analysis. First, monotonic and low cycle fatigue tests of HRB400E and HTRB600 steel with different slenderness ratios (L/D) were conducted to comparatively study their mechanical properties. Then, quasi-static cyclic tests of seven rectangular RC piers were conducted to study the effects of concrete cover, longitudinal reinforcement yield strength, concrete strength and axial load ratio on seismic behavior of RC piers. Finally, a fiber-based beam-column element was used to simulate the mechanical behavior of steel material and nonlinear response of RC piers. Material tests indicate that HTRB600 steel has lower uniform and fracture elongations, as well as inferior low-cycle fatigue performance than HRB400E steel. Increase of the slenderness ratio (L/D) severely weakens low-cycle fatigue life of steel bars, and the low-cycle fatigue parameters of steel can be fitted for each slenderness ratio, respectively. Even though HTRB600 steel has relatively lower ductility and inferior low-cycle fatigue performance, the RC piers with HTRB600 steel still have higher or at least comparable deformation capacity than that with HRB400E steel. This results from the reduction of strain demands of longitudinal bars by the utilization of HSSB in RC piers. Removing the concrete cover neighboring the longitudinal bars in the plastic hinge region has trivial impact on bar buckling and ultimate displacement of RC piers, which confirms that the concrete cover has already spalled off prior to the initiation of longitudinal reinforcement buckling. With identical steel strength and tie configuration, the ultimate displacement of RC pier with C80 concrete is significantly lower than that with C40 and C60 concrete, while the latter two have similar deformation capacity. Increase of axial load ratio (from 0.06 to 0.18) obviously reduces ultimate displacement of RC piers, since the concrete in the compression zone endures greater compressive stress under higher axial load and thus compressive failure occurs earlier. The ReinforcingSteel material model in OpenSees is calibrated by experimental data to accurately simulate the buckling and low-cycle fatigue properties of HRB400E and HTRB600 steel. The fiber-based finite element model (FEM) can predict the strain development of longitudinal bars of RC piers under cyclic loading, and the resulting low-cycle fatigue damage of steel material as well as strength degradation of RC piers. Combined with experimental study and FEM, this paper reveals the influence mechanisms of different factors on the seismic performance of RC piers in detail.

3D Finite Element Pseudodynamic Analysis of Deficient RC Rectangular Columns Confined with Fiber Reinforced Polymers under Axial Compression.

This paper utilizes the advanced potential of pseudodynamic three-dimensional finite-element modeling to study the axial mechanical behavior of square and rectangular reinforced concrete columns, confined with fiber reinforced polymer (FRP) jackets and continuous composite ropes in seismic applications. The rigorous and versatile Riedel-Hiermaier-Thoma (RHT) material model for concrete is suitably calibrated/modified to reproduce the variable behavior of characteristic retrofitted columns with deficient internal steel reinforcement detailing, suffering nonuniform local concrete cracking and crushing or bulging and bar buckling. Similarly, the 3D FRP jacket or rope confinement models may account for damage distribution, local fracture initiation and different interfacial bonding conditions. The satisfactory accuracy of the reproduced experimental stress-strain envelope behavior enables the analytical investigation of several critical design parameters that are difficult to measure reliably during experiments. Additional parametric analyses are conducted to assess the effects of steel quality. The significant variation of the field of developed strains on the FRP jacket at the ultimate and of the developed strains and deformations on steel cages among different columns are thoroughly investigated. This advanced analytical insight may be directly utilized to address missing critical parameters and allow for more reliable FRP retrofit design of seismic resistant reinforced concrete (RC) columns. Further, it allows for arbitrary 3D seismic analysis of columns (loading, unloading, cyclic or loading rate effects or preloading) or addresses predamages.

Axial compression behavior of ultra-high performance concrete columns confined by high-strength stirrups

Based on the axial compression test of 5 ultra-high performance concrete (UHPC) columns confined by high-strength stirrups and 4 UHPC columns confined by normal-strength stirrups, the bearing capacity, failure mode, steel strain and stress-strain curve for the confined UHPC columns were studied, and the influences of volume stirrup ratio, strength, spacing and configuration of stirrup on the axial compression behavior of confined UHPC were analyzed by combining ductility and toughness index. The results show that all the specimens have ductility damages, and the damage degree of UHPC columns confined by high-strength stirrups is lighter. The confined UHPC columns with high volume stirrup ratio, closely spaced, high-strength and complex ties configuration have good confinement efficiency, bearing capacity and deformation performance, which also leads to an ideal axial compression behavior. The effect of volume stirrup ratio on the axial compression behavior of specimens is greater than that of stirrup strength. Among the three factors affecting the volume stirrup ratio, such as spacing, configuration and diameter of stirrup, the stirrup spacing contributes most to the improvement of confinement performance, followed by the configuration and diameter of stirrup. The UHPC confined by high-strength stirrups presents better axial compression performance and residual bearing capacity than the normal-stirrups. The micro-bending of the longitudinal bars accelerates the cover spalling, while the high-strength stirrups with close space effectively delays the buckling of longitudinal bars, and significantly improves the overall performance of the confined UHPC. The micro-bending of longitudinal bars weakens the confine effect of the high-strength stirrups on the core UHPC, and the combination of high-strength longitudinal bars and stirrups is suggested. Based on the test data, the formulas to determine the bearing capacity of UHPC columns confined by stirrups are drawn.

Experimental Investigation on Cyclic Behavior of Reinforced Concrete Coupling Beams Under Quasi-static Loading

The current status of the reinforcement layouts stated in the codes and frequently used in new construction areas needs to be evaluated and determining its effects on the behavior of structural elements may provide essential contributions to the field. For this purpose, conventionally reinforced, diagonally reinforced (confinement of individual diagonals),and diagonally reinforced with full confined section concrete coupling beam specimens were designed according to ACI 318-14 and Turkish Earthquake Code 2018 in this study. ½-scale test specimens with aspect ratio two were tested under quasi-static cyclic loading using a new complex experimental setup. According to the results obtained, while for conventionally reinforced coupling beams ductile hysteretic behavior remained at 2.0% drift, for diagonal reinforced coupling beams it sustained up to 4.0% drift. Although the diagonal reinforcement enhanced ductility capacity of coupling beams compared to conventionally reinforced coupling beams having a comparably low post-elastic behavior, high ductility demands in the code requirements did not meet. For the same reinforcement ratio and layout, individual confinement around diagonal bars retarded bar buckling and ultimate strength and ductility capacity increased slightly compared to diagonally reinforced coupling beam with full confined section. After all, bar buckling that occurred after the life safety performance level given in the codes was seen at 3.5–4.0% drift. Diagonal reinforcing bars ensured life safety performance level up to 4.0% drift, but it remained at 3.0% drift for conventional reinforcement.

Development of performance limit states for concrete bridge piers with high strength concrete and high strength steel reinforcement

Current design codes and guidelines do not permit reinforcing the plastic hinge region of bridge piers using high strength steel (HSS) rebars. This is due to the lack of adequate research on the seismic response of HSS reinforced bridge piers. The objective of this study is to develop analytical expressions for predicting the drift at the onset of different performance limit states for high strength concrete (HSC) bridge pier reinforced with HSS reinforcement. Utilizing damage data obtained from incremental dynamic analysis of HSC circular bridge piers reinforced with HSS, this study developed drift ratio relationship accounting for the aspect ratio, concrete and steel material properties, axial load ratio, and reinforcement ratio, using validated finite element models. Analytical equations are developed for estimating the drift at the inception of rebar yielding, concrete spalling, and bar buckling using multivariate regression analysis. The proposed equations showed reasonable precision when corroborated against experimental results.

Lateral cyclic behavior of bridge columns confined with pre-stressed shape memory alloy wires

ABSTRACT This study focuses on investigating the effects of the wrapping mode of shape memory alloy (SMA) spirals with a large pre-strain on the lateral cyclic behavior of the bridge columns. The seismic performance of RC columns confined with different NiTiNb SMA spirals spacing and wrapping heights is compared through a series of quasi-static tests. The confined columns are tested under compression and cyclic lateral loadings. The lateral cyclic behavior of confined columns is compared with that of the as-built column. The test results demonstrate that NiTiNb SMA with a large pre-strain significantly improves the ductility and energy dissipation capacity, and has a slight effect on the peak lateral strength of the bridge piers. The SMA spirals reduce the crashing concrete zone and delay the buckling of steel bars in spite of the crack range in the SMA specimens increasing compared with the control column. The reinforcement effect increases as the SMA spirals spacing decreasing, particularly in terms of ductility and energy dissipation. The damage pattern has a slight distinction in the specimens strengthened by different wrapping mode.

Effects of longitudinal reinforcement discontinuities on the seismic response of structural walls

Lap splices and bar cutoffs introduce reinforcement discontinuities in reinforced concrete structures. A two-step approach was used to investigate the effect of longitudinal reinforcement discontinuities on the seismic performance of reinforced concrete structural walls. In the first step, six cyclic tests on small-scale reinforced concrete structural walls were conducted to study the effect of bar cutoffs. Three of the six specimens had web longitudinal reinforcement cutoffs to simulate the effects of a retrofit practice used in Japan. The test results indicated that this discontinuity resulted in approximately 50% increase in the unit tensile strains in the longitudinal reinforcing bars in boundary elements. Larger unit tensile strains caused an increase in permanent strain accumulation, increasing the likelihood of bar buckling. In the second step, the mentioned test results were combined with test results from previous tests (that investigated discontinuities related to lap splices) to calibrate equations for estimating drift capacity of structural walls with and without reinforcement discontinuities.

Long-stroke shape memory alloy restrainers for seismic protection of bridges

To prevent unseating failures and pounding problems in simply supported bridges, steel restrainers that can limit relative displacements of adjacent spans have commonly been used. This study proposes a shape memory alloy (SMA)-based restrainer that can serve as both energy dissipater and restrainer under cyclic tension and compression loading. The proposed device named as, long-stroke SMA restrainer (LSR), consists of a superelastic SMA bar, a steel tube, and a filler material. The SMA bar provides re-centering force and dissipates energy, while steel tube and the infill material prevent buckling of SMA bar under compression. Taking advantages of large strain capacity of SMAs, the LSRs are designed to accommodate large displacement demands for bridge restrainers. The mechanical response of NiTi SMA bars with a diameter of 12 mm was first studied through uniaxial tension and compression testing. Buckling and post-buckling response of the SMA bars were also characterized. Then, a high-fidelity finite element (FE) model was developed and validated to represent the behavior of SMA bars. Next, the buckling mechanism of proposed LSR was studied through FE simulations and a design methodology for the LSR was developed to prevent buckling. Results shows that the LSR can exhibit stable energy dissipation capabilities with excellent self-centering ability both under tension and compression loading and can serve as an effective restrainer in simply supported bridge structures.

Numerical investigation of HSC column under axial and flexural loading using 3D-NLFEA

High strength concrete (HSC) has been widely used as material for Reinforced Concrete (RC) column in high rise building in the past two decades. However, ductility of HSC column was one of the main concerns in design. The ductility of HSC column is much lower compared to normal-strength concrete. To increase the ductility of HSC column, the use of adequate transverse reinforcement can be used. In this paper, numerical investigation of HSC column available in the literature is modelled using an inhouse finite element package called 3D-NLFEA. The modelled specimen consisted of HSC columns with dimension 305 m x 305 m x 1473 mm and is subjected to constant axial load and incremental displacement control which act as a shear load up to failure. From the comparisons with the available test results, it was found out that the prediction using 3D-NLFEA agrees well with the test results. This paper also discusses the yield point location of bars in the load-deflection curve, length of bar that yields, buckling of compression bar, and concrete which cracked or crushed.