Possible Modes Of Failure Research Articles

Effect of marginal beams on the punching shear capacity of concrete slabs at exterior columns

It is common in concrete flat plate construction to connect the exterior columns with marginal, or edge, beams. In addition to the benefit gained from marginal beams in stiffening the slab edges and supporting the concentrated loads on the slab edge, they aid in resisting punching shear at the exterior columns. However, in most cases the marginal beam dimensions are limited by architectural constraints rendering it very small relative to the adjoining columns. In such cases, especially ones when the column protrudes beyond the beam width, the effect of the beam in resisting punching shear is doubtful. Most design codes do not provide a direct method for checking punching shear taking into account the effect of the beam, which might encourage designers to neglect punching shear design due to beam effect. This paper investigates the effect of marginal beams on the punching shear capacity of slabs at edge and corner columns. To the authors’ knowledge, only the Australian Standards (AS3600) accounts for that case, however; the AS3600 provisions are based on studies conducted on beams with width equal to the adjoining column width, a case which is out of the scope of this paper. The results of eight experimentally tested slabs were used to verify the modeling approach used to generate the parametric study models. The test specimens chosen for verification of the numerical model represented two possible modes of failure, punching shear at the column slab interface and torsion shear failure of the marginal beam. Numerical models of 80 slabs were developed using ABAQUS software package. The study results were compared to three international code provisions, the ACI318, EC2 and ECP-203. The study concluded that the presence of a beam with width less than 80% of the column width does not eliminate the punching shear mode of failure, however; the beam increases the overall capacity of the connection by transferring part of the load directly to the column and reducing demand on two-way shear. Design guidelines are presented to check shear capacity of such connections.

A Deep Learning Game Theoretic Model for Defending Against Large Scale Smart Grid Attacks

Power grids that are interdependent with communication networks create more possible modes of failure (e.g., cyberattacks) as well as more complex propagation of failure through the coupled networks. To ensure robust defense of smart grids, it is important to model both attacker and defender as intelligent, a scenario that the framework of game theory provides methods to analyze. However, prior works in applying game theoretic models to smart grid security limit the problem space to a small number targets under threat due to the inability of state-of-the-art methods to scale to large networks. Our method scales to large networks by combining neural networks that use featurized action representations with an approximation of large combinatorial actions to generalize knowledge about the best targets to attack/defend across graphs of various topologies and sizes. Our model’s invariance to the size of the input graph allows us to transfer knowledge from games played on small graphs during training to large graphs during evaluation. Our experiments show that our method can learn Nash equilibrium strategies on small networks, and demonstrate low exploitability when generalized to large networks, especially compared to the common heuristics currently used to simulate attacks on large graphs.

Cast-in and post-installed rebar anchorage systems in RC column foundation joints: System specific assessment and design

For assessment and design of post installed reinforcing bar (rebar) anchorages in reinforced concrete (RC) construction, two different approaches (i) conventional RC approach and (ii) fastening technology approach, coexist. For high strength adhesive systems, it is likely that the design anchorage lengths obtained using the fastening technology approach are significantly smaller in comparison to that obtained using the conventional RC approach. The main reason for this gap between the two approaches is, that while conventional RC approach considers qualified post installed (PI) systems as equivalent to cast in straight systems (CIS), PI systems are considered to be system specific in fastening technology. The system specific consideration of PI rebar anchorages in fastening technology makes it possible to take advantage of the higher bond strengths of the innovative adhesive systems, which is not possible in conventional RC design.This paper considers a comparison of the available approaches for assessment of rebar end anchorages in RC column foundation joints (CFJ). To this end, the benchmark test data generated by the authors [1] is used for the comparative discussions in the background of possible modes of failure. To include system specific definition of bond resistance in conventional RC approach, the potential of the system specific bond model in fastening technology to replace the general bond model in conventional RC practice for rebar anchorages is discussed. The alternate possibility of evolving the existing bond model in RC practice for including system specific consideration is also discussed. It is observed that the system specific definition of bond resistance within the framework of RC design practice is more suitable for rebar end anchorages. A proposal for failure hierarchy based assessment approach employing this system specific definition is made in this paper. The proposed approach is successfully validated to demonstrate its capability to assess both the failure loads and failure modes in a realistic manner, irrespective of the type of anchorage (cast in or post installed). The proposed approach is in concurrence with RC design practice and at the same time does not conflict with fastening technology. The presented is thus, a comprehensive breakthrough towards harmonizing the coexisting design concepts for rebar end anchorages.

Probabilistic calibration of environmental reduction and partial safety factors for the design of reinforced concrete beams strengthened by flax fibre reinforced polymers based on two-factor accelerated degradation tests

The main topic of this article is the probabilistic-based calibration of environmental reduction and safety coefficients for the design of reinforced concrete civil engineering structures repaired or strengthened by externally bonded flax fibre reinforced polymers (FRP). In view of the poor feedback on the durability of flax fibre composite materials used in civil engineering and the impossibility of conducting performance tests over several years, a two-factor accelerated test campaign based on the stimulation of composite degradation by increasing both temperature and humidity conditions was conducted. Flax-FRP (with a bio-based epoxy matrix) laminates and Flax-FRP-strengthened concrete slabs have been exposed over a period of two years to various couplings of temperature (from 20 °C to 60 °C) and humidity (from 50 % of relative humidity to water immersion), according to an asymmetrical Hoke design of experiments. Similar specimens were also exposed to outdoor natural ageing (climate of Lyon, FR) over a period of three years. Series of tests (more than 320 tests) aimed at monitoring the evolution of the degradation of mechanical characteristics (tensile capacity, tensile stiffness, shear strength, pull-off strength) directly associated with the possible modes of failure of structural elements repaired by composites, were carried out on control and aged specimens. A degradation model of these mechanical characteristics considering the competition of two mechanisms - inducing non-monotonic degradation-, and the influence of the temperature and the humidity - through the Eyring model -, was then developed and finally extended to consider the variability of the degradation under different climatic zones. On this basis, a reliability-based approach was adopted to propose environmental reduction and safety coefficients calibrated for Flax-FRP found within four international design guides (Fib bulletin 40, ACI-440, AFGC and TR55 guides). Finally, we showed the necessity to provide adaptable coefficients according to the climatic conditions in which the Flax-FRP elements will be installed.

A Study on the Capacity of Steel Portal Frames using Shell Finite Elements

AbstractSteel portal frames are common structures used in practice. Owing to their optimization, members with tapered geometry and slender sections are prevalent. Since local buckling is a possible mode of failure, an additional complexity arises that requires the use of shell finite elements to assess the ultimate capacity of these structures. On the other hand, imperfections, either of geometric or material nature, must be considered because they are unavoidable and reduce the overall capacity of the frames to carry load. The main focus of this study is therefore to characterize the influence of imperfections. Plate imperfections (or local), global (or member) and frame imperfections, are considered as well as material imperfections such as residual stresses that may contribute to degrade the frame's behaviour.An extensive parametric study comprising a total of 24 frames and 15 different imperfection sets was carried out and based on this large pool of results, recommendations for the definition of imperfections are given and conclusions are drawn on their influence. This work aims to be a step further in establishing a numerical framework to generate results that can be later used to validate existing design methods.

Toward Key Research Gaps in Design Recommendations on Flexurally Plated RC Beams Susceptible to Premature Failures

Beams that are strengthened with a plate at a soffit are susceptible to premature failure (peeling and debonding). Internationally available design standards provide varied recommendations that need to be compared. In addition, the models are too simplified (ACI440) or complex (FIB14), which miss some key parameters. This study will attempt to extend the design recommendations by proposing theoretical solutions based on the design codes (BS:5400 and IS:456). Ten different cases of possible modes of failure will be specified that specifically categorize peeling and debonding. Experiments will be conducted to identify the reasons why peeling failure is different from shear failure, which is an important criterion for the selection of appropriate models. The selected predictive models will be compared using a database of 507 beams to identify safety zones. Experiments from the literature will be selected to cover a wide range of geometrical and material properties and will be used to conduct parametric studies, which will lead to the design recommendations. ACI440 and FIB14 deviated significantly from the experimental observations. The results (with practical significance) and Chi-squared test (χ2) demonstrate that the proposed design formulations and recommendations are suitable to predict the moment capacity and failure mode.

Failure analysis of articulated paddings at crossing interface between crossing cable and crossed pipeline

While subsea crossings are undesirable for many reasons, they are unavoidable due to the sheer density of subsea assets . The use of articulated paddings is a cost-effective and practical method to achieve the required vertical separation between the crossing and the crossed pipelines or cables, though, not without limitations. In this paper, the failure of articulated padding at several points along a subsea cable in operation was investigated. The articulated padding has experienced partial fractures at numerous crossing locations and in some places has fallen off the cable completely. A complete failure mode analysis was conducted where several possible modes of failure were considered in detail. In-place finite element (FE) analyses of the articulated padding components and the corresponding environment were also performed. The FE modelling concluded that the original design loads were significantly lower than the expected worst-case load scenarios. To replicate the failure mode, two abrasion tests were also conducted and the results of which were studied. It was concluded that the predominant failure mode (partial fracture to the articulated padding discs) was likely a combination of the increased dynamic loads, excessive lateral movement causing unexpected levels of fretting, unbalanced free span causing unexpected stress concentration factors and reduction in material mechanical properties. All above factors have contributed to the root cause of the system failure and instigated the predominant mode of failure “partial fracture”.

Assessment of kinematic rock slope failures in Mudurnu Valley, Turkey

Slope instabilities are one of the most frequent natural hazards capable of causing severe failures both at regional and large scales. Mudurnu, which is settled on a steep valley, is affected by regional rock slope instabilities. These instabilities constitute a hazard and create an important risk to the community since they threaten human lives, settlement areas, and historically-important structures. In order to minimize the hazard and risk associated with slope instabilities, rock masses along the valley were characterized and the potential failure mechanisms were defined. The west side of the valley, which is the focus of the research, is characterized by Cretaceous pelagic discontinuous limestone, and is prone to complex failures. The aim of the study is to characterize the rock mass along the valley, divide the area into geomechanically-uniform sectors, define possible modes of failure (kinematics) and ultimately quantify the potential failure (kinetics) and the associated risk. For the study, in addition to the field work and scan-line survey measurements, an Unmanned Aerial Vehicle (UAV) was utilized to collect high-resolution images from problematic locations that were not accessible. Then, a point cloud of the area was generated. The images were interpreted and the resulting structural representation of the rock mass was compared with information gathered from the scan-line survey in the field. Afterwards, it was used to identify the possible modes of failure along the valley. Since seismic activity in the area is significant due to the proximity of the North Anatolian Fault Zone (NAFZ), which is the most active fault system in Turkey, dynamic loading was also considered for the stability analyses.

Experimental and numerical study on the mechanical behaviour of CLT shearwalls with openings

An investigation of the mechanical behaviour of CLT shearwalls, where either door or window openings are cut out of the panel, is undertaken. The main aim of the study is to investigate failure modes related to either mechanical anchor or CLT panel, based on the geometrical dimensions and mechanical properties of shearwall. The results of six full-scale monolithic CLT shearwalls with window or door openings are presented and discussed. The results obtained from the full-scale shearwall tests are used to validate a proposed numerical model, where input parameters, such as the mechanical properties of the CLT panels and mechanical anchors, are obtained from component level tests on beams and connections in isolation. The study shows that differently from single-panel shearwalls with no openings, brittle failure in the CLT panels is a possible mode of failure, which needs to be considered in design. The failure mode in the CLT panels is observed to occur either in bending or net shear in the lintel beams. The proposed numerical procedure is found capable of estimating the maximum load with reasonable accuracy, and the model predictions of the failure mode, number of centre of rotations, and the overall deformation of the CLT panel are accurate for all the studied specimens.

Predictive Computational Model for Damage Behavior of Metal-Matrix Composites Emphasizing the Effect of Particle Size and Volume Fraction.

In this paper, an integrated numerical model is proposed to investigate the effects of particulate size and volume fraction on the deformation, damage, and failure behaviors of particulate-reinforced metal matrix composites (PRMMCs). In the framework of a random microstructure-based finite element modelling, the plastic deformation and ductile cracking of the matrix are, respectively, modelled using Johnson–Cook constitutive relation and Johnson–Cook ductile fracture model. The matrix-particle interface decohesion is simulated by employing the surface-based-cohesive zone method, while the particulate fracture is manipulated by the elastic–brittle cracking model, in which the damage evolution criterion depends on the fracture energy cracking criterion. A 2D nonlinear finite element model was developed using ABAQUS/Explicit commercial program for modelling and analyzing damage mechanisms of silicon carbide reinforced aluminum matrix composites. The predicted results have shown a good agreement with the experimental data in the forms of true stress–strain curves and failure shape. Unlike the existing models, the influence of the volume fraction and size of SiC particles on the deformation, damage mechanism, failure consequences, and stress–strain curve of A359/SiC particulate composites is investigated accounting for the different possible modes of failure simultaneously.

Pitting of carbon steel in the synthetic concrete pore solution

AbstractPitting corrosion is a possible mode of failure of the carbon steel overpack of the Belgian supercontainer concept for the isolation of high‐level nuclear waste (HLNW). However, no firm experimental data are currently available to estimate the probability of failure over the extended storage time (100,000 years). Extensive work shows that passivity breakdown results from the condensation of cation vacancies (CVs) at the metal/barrier layer (m/bl) interface, in response to the absorption of Cl− into oxygen vacancies at the surface of the barrier oxide layer. The CVs migrate across the bl to the m/bl interface where they condense, leading to the separation of the bl from the metal. The resulting blister prevents the growth of bl into the metal and dissolution results in blister rupture, marking a passivity breakdown event. Stabilization via differential aeration produces a potentially damaging, stable pit. We review our work on passivity breakdown and the nucleation of pits on P355 QL2 carbon steel in high‐pH aqueous media typical of concrete pore solution, with emphasis on the mechanistic aspects. We conclude that failure of the carbon steel overpack containing the HLNW over a storage horizon of 100,000 years is improbable.

Numerical studies on two-tiered MSE walls under seismic loading

Mechanically Stabilized Earth (MSE) retaining walls, reinforced by the geogrids and using rigid segmental blocks as facing elements have extensively been used in recent past as an economic and sustainable solution for the earth retention. Nevertheless, in the case of a high retaining wall, tiered walls are preferred than a single-tier retaining wall due to their cost-effectiveness and more stability than single-tiered MSE walls. However, the behavior of tiered MSE retaining wall under dynamic loading is not yet studied thoroughly as the conventional design in practice is based on offset distance between the tiered walls and certain assumptions of surcharge loading imparted by the weight of tiered walls itself. Therefore, an attempt has been made to examine the behavior of tiered MSE retaining wall using finite element method, having a height of 12 m (H) under gravity and seismic loading to compare its stability with the conventional (single-tier) MSE retaining wall in terms of factor of safety (FOS) and to look into the possible modes of failure. The factor of safety shows a raise of 66% in two-tiered walls, when the horizontal seismic acceleration coefficient (kh) is 0.36 for both the walls, during the analysis of single-tiered and two-tiered wall systems. An optimum reinforcement length is evaluated for two-tiered wall system under seismic and static loading conditions. It is suggested that reinforcement 0.8H and 1.1H is suitable in two-tiered MSE walls, under static and dynamic loading respectively.

How Do the Locking Screws Lock? A Micro-CT Study of 3.5-mm Locking Screw Mechanism.

To quantify the amount of the screw head thread and the plate hole thread connection in two 3.5 mm locking plates: Locking Compression Plate (LCP) and Polyaxial Locking System (PLS). A micro - CT scan of a screw head - plate hole connection was performed pre- and post destructive tests. Tests were performed on bone surrogates in a fracture gap model. The 3.5 LCP and 3.5 PLS plates, with 3 perpendicular screws per segment were used in a destructive static test. The 3.5 PLS plates with mono- and polyaxial screws were compared in a cyclic fatigue tests in two orthogonal directions. Pre - and post - test scan datasets were compared. Each dataset was converted into serial images depicting sections cut orthogonally to locking screw axis. The amount of engagement was detected through automated image postprocessing. The mean amount of the thread connection for the LCP was 28.85% before and 18.55% after destructive static test. The mean amount of the connection for the PLS was 16.20% before and 14.55% after destructive static test. When inserted monoaxially, the mean amount of the connection for the PLS screws was 14.4% before and 19.24% after destructive cyclic test. The mean amount of the connection for the polyaxial inserted PLS screws when loaded against plate thickness was 2.99% before and 2.08% after destructive cyclic test. The mean amount of the connection for the polyaxial inserted PLS screws when loaded against plate width was 3.36% before and 3.93% after destructive cyclic test. The 3D visualization of the thread connection showed that the initial interface points between screw head and plate hole are different for both LCP and PLS after the destructive testing. Depending on the type of applied force, there was either loss or increase of the contact. Micro-CT offers news possibilities in locking implant investigation. It might be helpful in better understanding the nature of locking mechanism and prediction of possible mode of failure in different systems.

Thermomechanical Solid Breeder Multiple-Effects Experiment (TESOMEX) with Volumetric Heating and FEM Benchmark Analysis

Available experimental efforts on ceramic pebble beds and their associated constitutive equations are necessarily derived from single-effect tests where one parameter is varied and its effects are isolated and studied separately (e.g., using constant temperatures and externally applied loads). These experiments are incapable of reproducing the true multiple/synergistic effects of the physics that occur in real blankets, and the phenomena arising from the interactions of single effects are yet to be discovered. It is unclear whether the combined effect of plasticity and creep under reactor-relevant loading conditions will either enable the altered pebble bed packing configuration to reach an acceptable self-regulating temperature state or significantly deteriorate its heat transfer efficiency and subsequent tritium release. Therefore, studying the isolated thermal and mechanical effects is not sufficient to predict pebble bed behavior. It is the coupling and interdependence between the dynamic thermal and mechanical fields, as well as the synergistic effects between the various modes of deformation, that are key to fully understanding and predicting pebble bed behavior in a realistic fusion environment. However, previous mock-up experimental campaigns thus far have suffered from critical shortfalls that have severely hamstrung their scientific impact. The lack of experimental data that incorporate multiple-effects interactions in addition to the complexity of building a full-scale breeder unit mock-up triggered the need for this experimental effort. The body of work presented in this paper serves to (1) establish and validate the practicality of various volumetric heating simulation techniques for representative thermomechanical study, (2) recreate a prototypical breeder unit’s thermal-hydraulic behavior using a scaled-down reduced-activation ferritic steel box with optimized manifold design, (3) evaluate the thermomechanical properties of the pebble bed using a novel nonintrusive in situ tactile-pressure-sensing technology capable of generating real-time contact pressure maps that reveal spatial and temporal stress evolution, and (4) develop and benchmark a thermomechanical finite element method code that is able to predict the pebble bed’s thermomechanical evolution under the effects of creep and thermal cycling. The results of this study not only present novel experimental techniques and data that enhance our understanding of synergistic thermomechanical interactions and effects, but they also provide valuable data to serve as a basis for validation of the most recent pebble bed numerical models. Finally, it is worth mentioning that this work is part of a compendium around the Thermomechanical Solid Breeder Multiple Effects Experiment experimental campaign, known as TESOMEX. While this paper primarily focuses on novel heating and instrumentation techniques along with their opportunities and limitations, the other two papers shed more light on the prototypical thermomechanical evolution, pebble sintering, and possible modes of failure.

Ultimate strength and fracture sequence of bolted connections to thin-walled carbon steel

Recent experimental studies on single shear bolted connections to thin-walled carbon steel indicated the need for parametric analysis to understand the behaviour of the connection. In this paper, finite element analysis was performed to investigate the ultimate behaviour and failure sequence of these connections. A parametric analysis was performed to investigate the effect of plate thickness, end distance and curling displacement on the connection behaviour. Five possible modes of failure were identified and analytical models for estimating the connection strength for these modes were proposed. Within the range of the validity of the study, the end distance was the most influential parameter, but the strength improvement becomes negligible at edge distance of 42 mm for plate thickness less than or equal to 3.5 mm and 48 mm for plate thickness greater than 3.5 mm. Therefore, it is recommended to limit the maximum end distance to 50 mm. The curling displacement is found to affect the stress distribution in the plate as it could reduce the connection strength by 12%. It is considered as a sign of failure only when it reaches 0.5 mm before the ultimate strength of the connection is reached. The proposed models are more accurate in predicting the connection ultimate strength when compared to EC3, AISI and AISC predictions.

Failure mode analysis of laminated composite sandwich plate

Failure mode prediction of laminated composite sandwich plates is presented using improved higher order shear deformation theory (IHSDT) mathematical model and its C0 finite element (FE) implementation in FORTRAN. The proposed 2D IHSDT satisfies the inter-laminar shear stress continuity at each adjacent layer and nil transverse shear stress conditions at top and bottom of the plate are imposed. The parabolic shear stress variation is piecewise across thickness of each layer; hence no need of shear correction factors. The possible modes of failures are transverse matrix cracking, fiber breakage and inter-fiber shear failure of the matrix. The failure mode along with its location for laminated composite sandwich plates are obtained and are found in good agreement with the available 3D elasticity results.

Investigation of the Lateraltorsional Buckling Behaviour of Engineered Wood I-Joists with Varying End Conditions

Abstract Beam members, especially those that have large depth/width ratios and long spans, are prone to lateral-torsional buckling as a possible mode of failure. Laboratory testing rarely takes into account actual end conditions and initial imperfection which might have a significant impact on the buckling behavior of beams. The current research project aims to investigate the lateral-torsional buckling of wooden I-joists with realistic boundary conditions used in construction. A total of 41 joists were tested using various commercial joist hangers and enhanced connections to represent different support conditions. A numerical 3D model was also developed using commercially available finite element program ABAQUS to determine the buckling loads and associated mode shapes of joists similar to those tested. Based on the results from the current study it is recommended that 20% reduction in the critical moment capacity be considered in order to take into account the use of joist hangers typically used in construction. Finite element analysis of the linear eigenvalue buckling load was found to be in reasonable agreement with the experimental results. The nonlinear behavior of the joists was found to be influenced by the initial imperfections. The ultimate critical load was attained at large lateral displacement of the joists due to their non-linear behaviour. This observation could have a significant implication on design and should be investigated further.

Investigation of the lateral-torsional buckling behaviour of engineered wood I-joists with varying end conditions

Beam members, especially those that have large depth/width ratios and long spans, are prone to lateral-torsional buckling as a possible mode of failure. Laboratory testing rarely takes into account actual end conditions and initial imperfection which might have a significant impact on the buckling behavior of beams. The current research project aims to investigate the lateral-torsional buckling of wooden I-joists with realistic boundary conditions used in construction. A total of 41 joists were tested using various commercial joist hangers and enhanced connections to represent different support conditions. A numerical 3D model was also developed using commercially available finite element program ABAQUS to determine the buckling loads and associated mode shapes of joists similar to those tested. Based on the results from the current study it is recommended that 20% reduction in the critical moment capacity be considered in order to take into account the use of joist hangers typically used in construction. Finite element analysis of the linear eigenvalue buckling load was found to be in reasonable agreement with the experimental results. The nonlinear behavior of the joists was found to be influenced by the initial imperfections. The ultimate critical load was attained at large lateral displacement of the joists due to their non-linear behaviour. This observation could have a significant implication on design and should be investigated further.

Tensile Resistance of GFRP Wrapped Steel-Dowelled Half-Lap Timber Connection

Generally, the use of timber mainly focuses on simple structures or structures that can take small loads. This paper report on tensile resistance of steel dowelled timber connection wrapped with glass fibre reinforced polymer (GFRP). It involved experimental work in laboratory designed to determine the tensile strength behaviour for half-lap timber connections with steel dowel as the mechanical fasteners. Bintangor species representing strength group 5 and Yellow Meranti species representing strength group 6 were tested in the conditions of with and without the GFRP wrapping. The performances of the connections were observed using the European Yield Model (EYM) as the guideline. The EYM theory is generally used to determine the load carrying capacity of timber-to-timber, panel-to-timber and steel-to-timber connections, reflecting all possible modes of failures. All half-lap connection members were tested at the rate 0.0006 mm/min using the universal testing machine. As a result, it was found that the steel-dowelled half-lap timber connection with GFRP wrapping performed better than the timber connection without the wrapping. The ultimate load of GFRP wrapped connections made of Bintangor and Yellow Meranti species were found increased at 17% and 44% higher compared to the connection without the GFRP wrapping accordingly.

Behavior of columns of steel plate shear walls with beam-connected web plates

Steel plate shear walls with beam-connected web plates (B-SPSWs) are an alternative configuration of steel plate shear walls (SPSWs) where web plates are connected to the beams only. Detaching web plates from columns and introducing simple beam-column connections in B-SPSWs eliminate flexural demands in the columns resulting from web plate tension field action; consequently, the columns of B-SPSWs are designed primarily for axial loads. A recent study, however, showed that the columns of B-SPSWs resist significant flexural demands during earthquake shaking due to differential interstory drifts that result in significant column rotations at floor levels. Typical design methods (i.e., the Equivalent Lateral Force method and Modal Response Spectrum analysis) do not capture these rotations associated with differential drifts that might lead to column instability. A two-phase numerical study is conducted to evaluate the behavior and stability of B-SPSW columns. In the first phase, three-dimensional nonlinear response-history analyses are conducted to investigate the column stability for eighteen B-SPSWs with different geometric characteristics designed following two design approaches. The results suggest that column buckling is a possible mode of failure for one of the design approaches. In the second phase, a parametric study is undertaken to further investigate potential column buckling failure modes in B-SPSW columns and to establish an upper-bound estimate for the column buckling strength reduction due to column rotations at floor levels that are not considered in traditional design approaches.