Search

The structural assessment of masonry construction often requires the use of nonlinear 2D and 3D finite element analysis. This work describes a strategy for using energy outputs from such analyses to accurately assess failure conditions precipitated by increasing lateral load. The methodology relies on the analogy between plastic strains and fracture that is inherent to the concrete damaged plasticity (CDP) macro-model used to represent the quasi-brittle behavior of masonry material. At critical conditions, energy imparted to a structure by loading can no longer be completely stored as elastic strain energy and must be dissipated. This occurs with fractures in masonry, which are represented with plastic strains when using CDP material. The development of plastic dissipation energy can therefore be used as a measure for understanding the progressive collapse of a structure, as we illustrate with the following three case studies analyzed using Abaqus/CAE Explicit: the massive earthen pyramid at Huaca de la Luna (Trujillo, Peru), the Roman pozzolanic concrete vault of Diocletian's Frigidarium (Rome, Italy), and the mixed-material triumphal arch of the San Pedro Apóstol Church of Andahuaylillas (Peru). The method is verified by other measures of failure and has particular applicability for seismic analysis of complex masonry and earthen structures. [ABSTRACT FROM AUTHOR]

AbstractIn the past decades, progressive collapse (PC) has been of growing importance. Better understanding this phenomenon is mandatory to propose ad hoc mitigation and design approaches. Many experimental studies are carried out on sub-assemblies in quasi-static conditions due to setup and cost of full-scale dynamic tests. Numerical simulations describe dynamic responses of whole structures, although result interpretation can prove tricky due to models’ complexity. Recommendations account for dynamic effects, combining static analyses with dynamic amplification factors; however, this cannot be applied to all types of PC scenarios. Thus, a new testing method is proposed: sub-structured pseudo-dynamic experiments are adapted to the PC framework. Sub-structuring couples an experimentally tested critical member with a dynamic finite element model of the whole structure. The latter simulates inertial and viscous forces, while the static contribution of the critical member is tested in quasi-static conditions. This article considers a column removal scenario on a reinforced concrete frame. The structure is modelled using multi-fibre beam finite elements. The tested member consists of the lower floor’s beams, subjected to compressive arch and tensile catenary actions. Pushover and PsD tests are presented, and highlight the interest of the method in providing additional information on the dynamic response. [ABSTRACT FROM AUTHOR]

This article presents an experimental and numerical study of the collapse behavior of a 60‐m‐high cement silo structure under blast loading, analyzed using SAP2000 (FEM‐NDA) and LS‐DYNA (FEM‐NDA‐explicit code) models to simulate the collapse mechanism. Considering the seismic events in Kahramanmaras, Turkiye, on February 6, 2023, with magnitudes of 7.8 and 7.6, the necessity for the explosive demolition of hundreds of thousands of structures has underscored the urgency of rapid planning. This situation requires a particular focus on the expeditious analysis of demolition methodologies. The study includes pre‐planning stages, sudden column removals and the detonation of columns with blast loads for the controlled demolition of a full‐scale existing silo structure. To overturn the structure, the columns inside the wedge region were suddenly removed using SAP2000 nonlinear dynamic analysis (NDA) to understand the subsequent load redistribution. A study was conducted to compare the use of shell and plate elements in SAP2000 for a 1‐m‐thick wall silo. The results showed that using shell elements provided relatively closer results to real values than plate elements. For the explicit analysis part, the structural components were modeled as solid materials, and columns were detonated with blast loads. The models and actual demolition frame‐by‐frame results of the structure were compared, and the numerical model's accuracy was validated using experimental data from stationary cameras and drones, with the explicit analysis results found to be in agreement. While explicit analysis yielded results more in line with real data, SAP2000 NDA provided relatively distant results, although SAP2000‐NDA was more time‐efficient compared to explicit analysis models. However, a preliminary evaluation can be made if the characteristics of both programs are understood. The documented information on full‐scale structure demolition and findings presented in this paper will serve as a resource for future studies and provide a reference for researchers. [ABSTRACT FROM AUTHOR]

The catastrophic events of September 11, 2001, stand out as a major motivation for research on improving the understanding of structural behaviour in fire. These events included the first complete collapse of a tall steel framed structure solely due to fire. World Trade Center 7 (WTC7) was a 47-storey office building within the WTC complex that collapsed due to a fire initiated by debris from the collapse of WTC1. In the following years, detailed investigations were carried out by expert teams to pinpoint the cause of the progressive failure of WTC7. Each of the expert teams analysed the fire and structure and made varying conclusions with regards to the mechanisms responsible for initiating and propagating the collapse of the building. This paper revisits the collapse of WTC7 and its investigation, and then explores the hypothesis that a potential hydrocarbon fire may have compromised the large transfer structure within the mechanical space of the building. This is done via two OpenSees finite element models. The first model explores the thermomechanical response of the mechanical floors to a potential diesel fire, and the second investigates the response of the structure to a failure caused by that fire. The outcome of the analyses shows that it is feasible that a mechanical room fire could lead to a failure in the transfer structure, which would then result in the loss of support to at least two columns within the building core. The failure of these columns may unbrace the eastern-most core columns and precipitate in the failure of the structure as observed on 9/11. [ABSTRACT FROM AUTHOR]

By analyzing the failure mechanisms, crashworthiness characteristics of FW composite tubes subjected to two modes of progressive damage and catastrophic failure are investigated using acoustic emission technique and numerical method. The AE signals of ±45° composite tubes were classified using hierarchical and wavelet transform methods, and based on the realistic and three-dimensional geometrical architecture of tubular structures, the microstructural finite element model was developed using Catia and ABAQUS software. Then deformation patterns and the impression of each mechanism on the crashworthiness characteristics were assessed. Results indicated that fiber breakage and fiber/matrix debonding could likely control the higher percentage of damage. By changing the type of modes from progressive damage to catastrophic failure, the percentage of matrix cracking increases, the fiber/matrix separation decreases, and the failure behavior become dominated by local buckling. Comparing the FE simulation with experimental results, we found the proposed 3D model can reasonably predict the pre-crushing, post-crushing, and material densification. [ABSTRACT FROM AUTHOR]

Quantitative analyses of structural resistance are useful during the design process to prevent the occurrence of progressive collapse. Buildings subjected to continuous instances of expected/non-expected loadings due to extreme events (e.g., earthquakes, explosions, floods, hurricanes) can collapse. A lack of specific knowledge from the designer and poor maintenance can affect collapse analyses. In this paper, the probability of failure for pancake collapse with respect to bending collapse for reinforced concrete (RC) multi-storey buildings is estimated. New combinations regarding the elastic/plastic behaviour of the material under distributed loadings on beams are proposed. Numerical 2D finite element method (FEM) analyses are carried out to model these buildings. Also, simplified dynamic analyses are carried out. The outputs are plotted in terms of the probability of failure for pancake collapse as a function of column compressive strength and the number of removed columns. The results show that the presence of elastic beams can influence the pancake collapse of columns, and, for buildings composed of several elements, the elimination of few elements has little impact on their stability. [ABSTRACT FROM AUTHOR]

The configuration of beam–column joints in precast concrete (PC) building structures varies widely, and different connection methods significantly affect the progressive collapse resistance of the structure. This study investigates the progressive collapse resistance of an innovative beam–column connection node frame. Finite element models of four-story, two-span space frame structures made of reinforced concrete (RC) and PC were developed using ANSYS 14.0/LS-DYNA R5.x software, employing nonlinear dynamic and static analysis to examine structural collapse behavior under bottom middle or corner column damage. Numerical results indicate that following the failure of the middle or corner column due to explosion loading, the vertical displacement and collapse rate of the PC structure with the novel connection method are less than those of the RC structure during collapse progression. Furthermore, upon removal of the middle or corner column, the residual load-carrying capacity of the PC structure with the innovative connection increased by 7% and 3.7%, respectively, compared to the RC structure. This suggests that PC structures with this type of connection demonstrate superior performance in resisting progressive collapse, offering valuable insights for future engineering applications. [ABSTRACT FROM AUTHOR]

To investigate the effect of the infilled wall distribution on the load of progressive collapse resistance of reinforced concrete (RC) frame structures, integral finite element models of RC infilled wall structures were established based on ABAQUS, and the rationality of the modeling method and the selection of the constitutive relation were verified by comparison with experimental results. Furthermore, the load-displacement relationship, the relationship between the horizontal displacement of joints and the vertical displacement of columns, the distribution of plastic hinge and the peak load capacity of RC frame structures with different numbers of infilled walls and distributions were analyzed. The results show that the infilled walls located at the failed column span can sig-nificantly improve the load of progressive collapse resistance of frame structures. The distribution of infilled walls will change the position of plastic hinges of the frame structures. Additionally, the more inhomogeneous the plastic hinge distribution, the weaker the progressive collapse resistance of structures. In architectural design, it is necessary to avoid the horizontal asymmetric distribution of the infilled walls and the situation that the infilled walls are only distributed at both ends of the floor. [ABSTRACT FROM AUTHOR]

The steel frame structure plays an important role in strategic deployments and is widely used in heavy machinery, metallurgy, military, and other important industries. To study the impact of explosive loads on the anti-progressive collapse performance of steel structures, this paper proposes to establish the vulnerability characteristics of steel frame structures and provides a method for calculating vulnerability characterization indicators. A finite element model is used to analyze the dynamic response of steel frame structures under the action of close-range explosive loads, and factors influencing the anti-progressive collapse of steel frame structures are proposed, including the number of stories and diagonal bracing. A comparison is made between the various column types of steel structures under explosive loads, such as corner columns, long-edge middle columns, short-edge middle columns, inner columns, also in various coupling conditions. The results show that the progressive collapse of steel frame structures is greatly influenced by the position of the explosion and less affected by the amount of explosive material. The simultaneous failure of corner columns and long-edge middle columns is more likely to cause overall structural failure. The addition of diagonal bracing significantly improves the anti-progressive collapse ability and prevents the lateral displacement of steel frame structures; increasing the number of stories provides more alternative load transfer paths for steel frame structures, thereby preventing their collapse. [ABSTRACT FROM AUTHOR]

Standard structural assessments of ship hulls include the evaluation of the elastic structural response. Elastic analysis neglects extreme and unpredicted loadings, which can produce catastrophic outcomes, such as the loss of the ship's ultimate strength. Moreover, hull elements are considered unaffected by age-related degradation. Therefore, this study models and quantifies the effect of corrosion-induced structural degradation on the ultimate strength of a high-tensile-steel (HTS) cargo ship using progressive collapse and nonlinear finite element methods. Uniform and pitting corrosion are modeled through selected scenarios, which hull elements might encounter during exploitation, producing a total of 148 calculation models. The findings show that corrosion-induced degradation can significantly decrease the ultimate strength of the hull (up to 30% for the most severe scenarios assessed). Furthermore, ultimate strength decreases almost proportionally to the amount of wastage considered. It was found that stiffener corrosion has a significant effect on the total ultimate strength. This study's aim is to emphasize the vast importance of including ultimate strength along with ageing effects in industry-standard structural assessments of large HTS ship structures, designed to last for several decades whilst exposed to excessive and unpredicted bending moments. [ABSTRACT FROM AUTHOR]

In order to study the effect of the support mode of a staggered truss system on the continuous collapse resistance performance of a steel structure, four finite element models were established based on the bracing arrangement of a five-story steel frame structure. The situations of different columns on the first floor removed were classified into eight scenarios, and five models of each scenario were analyzed with nonlinear dynamic analyses. Finally, a computational metric based on energy robustness was proposed to evaluate the robustness of the structure. The results of nonlinear dynamic analyses indicated that the staggered truss system significantly improved the resistance to progressive collapse of steel frame structures and effectively increased the redundancy of steel frame structures. All four bracing methods effectively reduced the vertical displacement at the point of failure, with the peak displacement at the point of failure reduced by a maximum of 84 percent and a minimum of 41 percent compared to a pure frame structure. Moreover, the staggered truss system can reduce some axial force peaks in the adjacent columns adjacent to the failed columns. The structural robustness coefficients of Model A, Scheme 1, Scheme 2, Scheme 3, and Scheme 4 are 1.144, 1.339, 1.306, 1.584, and 1.176, respectively, according to the proposed robustness calculation method, which shows that the braced steel frame structure has improved robustness over the original structure. The staggered truss system improves the robustness of the steel frame structure so that the steel frame structure has better resistance to progressive collapse. [ABSTRACT FROM AUTHOR]

This paper studies the dynamic response of corner-supported modular steel buildings with a core wall system, under progressive collapse scenarios, associated with corner module removals. Since using secondary systems such as concrete core in mid- to high-rise buildings is currently unavoidable, understanding their impact on load transfer between modules during collapse scenarios becomes essential. The designated four-, eight-, and twelve-story buildings were modelled using the macro-model-based finite element method in Abaqus. In addition, three different locations are considered for the concrete shear core within the building plan, leading to nine various case scenarios. Each vertical and horizontal inter-module connection was modelled by one axial and two shear springs with predefined nonlinear force-displacement behavior. The local and global buckling, which plays an essential role in the building's stability, was considered to obtain accurate results. Finally, parametric studies on the building response were carried out, including the intra-module connection rigidity and inter-module connection stiffness. The results demonstrated that the core wall could maintain the robustness of a modular steel building through two mechanisms dependent on its location within the plan. In addition, preventing plastic hinges from forming in beams could be introduced as an anti-collapse mechanism in the corner module removal scenarios. [ABSTRACT FROM AUTHOR]

This study presents experimental and finite element investigations on the ultimate strength of the funnel structure of a large passenger ship subjected to wind pressure. An experimental test is conducted using a similar model to analyze the failure characteristics of the funnel structure. The model is designed based on similar theories to simulate the progressive collapse behavior of an actual ship's funnel under wind load. Additionally, a simplified wind loading device is also developed to apply large wind loads. Practical insights are provided in the research to assess the opening's influence on reducing the ultimate strength of funnel structures when suffering wind pressure. Results represent the failure initiated at the edges of the large opening, with stress concentration primarily occurring at the stiffener end, showing good agreement with the simulated results performed using the finite element method. Furthermore, the effects of different parameters on the ultimate strength of the funnel structure are discussed by using the numerical method. This analysis provides an important guide for the design of funnel structures of passenger ships with openings. [ABSTRACT FROM AUTHOR]

Occurrence of progressive collapse events invariably leads to significant economic and human-life losses. Progressive collapse analysis and design of building structures have become a research hotspot worldwide. Existing studies have proved that development of extra load-carrying mechanisms could significantly improve the resistance of structures to progressive collapse. However, limited research has been conducted to quantitatively analyze these mechanisms. This study proposed a new and unified division method for mechanisms for resisting progressive collapse; furthermore, it provides a basis for their quantitative analysis. In addition, the progressive collapse behavior of a 1/3-scaled two-story, one-bay-by-two-bay reinforced concrete (beam–slab–column) frame with an edge column lost was experimentally investigated. Additionally, a 3 D solid finite element model was established and validated based on the test results. The effects of different extensive parameters, including ideal lateral constraints, slab thickness, and beam–slab interaction, on each resisting mechanism were quantitatively investigated. Finally, a new simple method for predicting the first peak load was proposed based on the contribution of each mechanism. The results from the simple method were in agreement with the simulation results of beam–slab–column structures. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Southeast University (English Edition) is the property of Journal of Southeast University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In practice, reinforced concrete (RC) infilled frames having longer span are provided with tie columns to improve structural integrity but previous work ignored tie columns in studying the effect of masonry infills on progressive collapse resistance of RC frames. Therefore, aim of this study is to explore the effect of tie columns on the progressive collapse resistance of RC infilled frames under column removal scenarios. The high-fidelity-based finite element model of RC infilled frames were first developed and validated with published experimental results. The validated model was then further evolved to an RC infilled frame having tie columns to evaluate the influence of tie columns on the load transfer mechanism and the resistance of the RC infilled frame against progressive collapse. Thereafter, the numerical model was further utilized to study the effects of the pertinent parameters, including the number of stories, the span length of the frame and the longitudinal reinforcement ratio of the tie columns. Finally, equivalent strut model was suggested for macro-modeling of RC infilled frames having tie columns in engineering practice. The results showed that incorporating tie columns makes truss mechanism more fully mobilized in masonry infill walls and the inclined angles of primary struts in each sub-panel of the infill wall are increased, improving the vertical components of diagonal compression in resisting the gravity load. Consequently, introducing tie columns at middle span of infill wall panels helped to increase the initial stiffness (about 19%), peak resistance (about 26%) and post-peak resistance of RC infilled frame under a middle column removal scenario. Such beneficial effect of tie columns becomes more significant for infilled frames with larger spans, and the longitudinal reinforcement ratio of tie columns should be ≤ 0.24%. [ABSTRACT FROM AUTHOR]

In view of the complexity of the pile foundation underpinning structure system and the stringent requirements of the construction process, this paper briefly describes the necessity of introducing epoxy resin reinforcing adhesive of planting rebar in the design of pile foundation underpinning beam structure to improve the mechanical properties of the reinforced beam new and old concrete joint surfaces and proposes a new type of pile foundation replacement beam system construction method by "chiseling + prestressed reinforcement + epoxy resin reinforcing adhesive". This paper uses an actual pile foundation underpinning project of an urban overpass as a prototype, designs and creates a model structure with a similarity ratio of 1/6, and performs repeated progressive static loading tests to study the load carrying capacity, displacement change, and other properties of the strengthened replacement structure, as well as analyses and distorts the overall working performance and failure mode of them. On this basis, the prototype structure's finite element analysis model was built, and the finite element analysis results were compared with the test results to obtain the mechanical properties and deformation characters of the actual pile foundation underpinning structure system corresponding to the actual underpinning beam load. This paper's study can lay the theoretical and experimental foundation for the smooth development of similar projects. [ABSTRACT FROM AUTHOR]

Progressive collapse is a dynamic loading incident triggered by the sudden loss of critical elements. Design codes provide simplified rules to consider the dynamic effects via the use of Dynamic Increased Factors in order to avoid complex and time‐consuming nonlinear time history analyses. In this paper, a nonlinear single degree of freedom (SDOF) system is presented that captures the dynamic response of steel frames subjected to a column removal scenario. The model takes into account inertia, damping effects and assumes an elastoplastic nonlinear resistance for the system. A closed‐form analytical solution for the dynamic equation of motion is derived and then is applied to a frame to simulate the response under a column removal scenario. A nonlinear finite element model developed in OpenSees was used to verify the accuracy of the analytical model. The results showed that the nonlinear response of the frame for the selected hazard event can be well captured with the proposed model. [ABSTRACT FROM AUTHOR]

Automated self‐supporting rack warehouses are becoming increasingly common in the international logistics sector. Their static and seismic design has been studied in the literature; however, the fire design still needs to be improved. Some Standards, such as the Eurocodes or Italian Fire Code, accept the collapse of rack warehouses during fires but require avoiding a progressive collapse or obtaining an implosive collapse regardless of any other active or passive fire protection systems. A hierarchy that guides the kinematics of collapse needs to be defined appropriately but without any Code going into further details. Moreover, the scientific literature focuses more on optimizing fire protection systems for racks, such as sprinklers, rather than preventing fire‐induced progressive collapse. Here, a case study is presented, which, using finite element modelling, provide a first robustness evaluation and highlights some possible aspects to be considered in the structural design to avoid a progressive collapse in the event of a fire. The analyses are performed using the LOCAFI method for localized fires and nonlinear dynamic finite element simulations. [ABSTRACT FROM AUTHOR]

In this paper, a new buckling-controlled member (BCM) is introduced for use in space structures. This member is composed of four components; namely: the encasing, joints, core, and adjustable nuts. The core is intended to act as a structural element to resist the axial loads by its yielding under compression loading. The steel encasing is supposed to confine the steel core. Adjustable steel nuts on the steel core act as lateral bracings and are responsible for lateral load transmission between the encasing and core. The joints at the two ends of the supports of the member. Six experimental tests have been performed under compression load to show the efficiency of the new member. The test results reveal that the proposed member can provide the needed ductility and can delay the brittle buckling of the members. Also, the BCM is capable of considering buckling modes and controlling the plastic range. The experimental and numerical results have also been compared. Additional numerical evaluations have been carried out using finite element models, in which the effects of different parameters of the member have been investigated. The obtained results showed that the arrangement of inner elements is the main factor affecting ductility and postponing the buckling of the members. In the end, the effects of the BCMs on the overall behavior of four double-layer space structures have been studied. The obtained results of analyses indicated that the BCMs can enhance the strength and ductility of space structures, thereby reducing the risk of collapse. Also, the seismic collapse of the space structure was postponed. [ABSTRACT FROM AUTHOR]

This study investigates the effect of spans length, reinforcement ratio and continuity of flexural reinforcement on the progressive collapse performance of double span beams over failed columns. The investigations focus on initial flexural resisting mechanisms to prevent progressive collapse. Detailed nonlinear finite element simulation of double span beam-column sub-assemblages subjected to residual gravity loads that initially carried by the failed column is adopted for the investigations. Nonlinear static pushover analysis is conducted in which capacity curves are derived and compared with demanded capacities. The effects of spans length, reinforcement ratio and number of continuous bottom flexural reinforcement on progressive collapse are considered in the investigations. Analysis results show that the strength to resist progressive collapse has decreased by 25.4 % and the ductility increased by 103 % following the increase in span length from 5 m to 7 m. On the other hand, increasing reinforcement ratio of top flexural reinforcement from 0.447 to 1.089 leads to 26.27 % increase in strength accompanied with a decrease in ductility equal to 16.42 %. In addition, extending all bottom bars rather than the minimum specified two bars resulted in 12 % increasing in strength and 40.28 % decreasing in ductility. [ABSTRACT FROM AUTHOR]

Mobilisation of alternate load path (ALP) mechanisms in three-dimensional (3D) beam–slab systems is a key factor in designing structures against progressive collapse. Existing analytical methods on 3D beam–slab systems focusing on limited load-resisting mechanisms often lead to uneconomical and unrealistic design, while finite element models with 3D solid elements are too complicated and time-consuming for 3D beam–slab systems. To address these shortcomings, this paper aims to provide structural engineers with two simple but effective and reliable approaches to predict the structural behaviour of 3D beam–slab systems. They include (i) an analytical method and (ii) a simplified finite element model based on strip method and grillage analysis. Both approaches are validated against published test results for 3D beam–slab systems. Compared to existing approaches on 3D beam–slab systems, these two proposed methods incorporate all the load-resisting mechanisms in both the beams and slabs, giving more accurate and realistic predictions of load–displacement curves for the sub-structures considered. In addition, parametric studies on the analytical approach are presented to shed light on the role of boundary conditions and the contribution of slabs to the load resistance capacity of 3D beam–slab structures against progressive collapse. [ABSTRACT FROM AUTHOR]

Airborne electromagnetic (AEM) surveys using airborne mobile platforms enable rapid and efficient exploration of areas where groundwork is difficult. They have been widely used in fields such as shallow resource exploration and environmental engineering. Three-dimensional AEM inversion is the main technique used in fine structural interpretation. However, most current methods focus on separate component data inversions, which limit the kinds of structures that can be recovered in the inversion results. To address this issue, a method for the robust 3D joint inversion of multicomponent frequency-domain AEM data was developed in this study. First, a finite element method based on unstructured tetrahedral grids was used to solve the forward problem of frequency-domain AEM data for both isotropic and anisotropic media. During inversion, a limited-memory quasi-Newton (L-BFGS) method was used to reduce the memory requirements and enable the joint inversion of large-scale multicomponent AEM data. The effectiveness of our algorithm was demonstrated using synthetic models for both isotropic and anisotropic cases, with 5% Gaussian noise added to the modeling data to simulate the measured data for separate and joint inversions. The results of the synthetic models show that joint inversion has advantages over separate inversion in that it enables the recovery of finer underground structures and provides a novel approach for the fine interpretation of frequency-domain AEM data. [ABSTRACT FROM AUTHOR]

Corroded transmission towers, whose load-bearing capacities are lowered, are suffering from wind-induced damage. By simulating the member corrosion through section thinning, the structural dynamic finite element model of an angle-steel transmission tower with a corrosion depth of 0 mm to 1.4 mm was established using ANSYS/LS-DYNA software. The incremental dynamic analysis method was used to study the collapse mode of the tower under different degrees of corrosion, as well as the effects of corrosion on structural self-vibration characteristics, wind-induced member stress, and tower-top displacement. The results show that with the corrosion deepening, the first three vibration frequencies decrease, and the torsional mode becomes the first mode. When the corrosion depth is smaller, the overall structure failure occurs under strong wind. The failure starts at the most unfavorable oblique rod between the upper and middle cross arm, then expands to the rods under the lower cross arm. When the corrosion depth is larger, the overall structure failure occurs restrictedly between the upper and middle cross arm. Internal axial force and bending moment redistribution happen when corrosion deepens. Under the critical failure state, the oblique rods are always at a high stress level, while the stresses of the main rods decrease. Corrosion has a stronger impact on component strength and stability than on structural stiffness. [ABSTRACT FROM AUTHOR]

Many studies have been carried out for understanding the mechanism of failure of RC structural systems under varying temperature circumstances. Similarly, several methods have been developed for improving the fire resistance of concrete buildings, with respect to material selection and detailing aspects. However, only some of the researchers have concentrated on composite behavior of interaction between the structural elements and functional elements, like interaction between masonry infill walls and RC frame elements in the emergence of fire. Several numerical models have been developed for analysis of infilled frames. For simulating the action of fire on full-scale reinforced concrete buildings, three factors, namely, presence of loading, place of fire, its intensity, and duration, must be considered since the material behavior depends on the stress level, intensity and duration of fire and the sensitiveness of structural element to the location and application of fire. To consider the combined effect of load and high temperature, finite element analysis is used. For simulating the intensity and time factor for temperature rise, transient state studies must be done. [ABSTRACT FROM AUTHOR]

The gable wall of the conventional island of a nuclear power plant carries various pipeline loads connecting the nuclear island and the conventional island. If the gable wall collapses and is damaged due to the progressive collapse of the main plant structure of the conventional island, it will directly threaten the safety of the nuclear island. Therefore, it is of great significance to systematically study the resistance of the gable structure of the nuclear island to progressive collapse for the safe operation of nuclear power plants. Based on the SAP2000 finite element analysis platform, this paper established a model of the reinforced concrete frame structure of the first span of the shield building on the conventional island of a nuclear power plant, including the gable. According to the alternate path method, the node displacement and bearing capacity responses were used to determine the critical components in the gable, and single column failures of the top four in importance were selected as different analysis conditions. Nonlinear static and dynamic methods were used to analyze the displacement, internal force change, hinge sequence of the gable structure on the side of the nuclear island, and the ability of the gable to resist progressive collapse. The analysis results showed that the gable structure of the nuclear island had good resistance to progressive collapse under four single column failure conditions, whether by nonlinear static or dynamic analysis, and the overall vertical displacement obtained by the nonlinear static analysis was larger than that obtained by the dynamic analysis. [ABSTRACT FROM AUTHOR]

This study extends the authors' previous numerical and experimental studies simulating the progressive collapse of steel stiffened-plate structures in fire events (Paik JK, Ryu MG, He KH, Lee DH, Lee SY, Park DK, Thomas G. 2021a. Full-scale fire testing to collapse of steel stiffened plate structures under lateral patch loading (part 1) – without passive fire protection. Ships Offsh Struct. 16(3):227–242; Paik JK, Ryu MG, He KH, Lee DH, Lee SY, Park DK, Thomas G. 2021b. Full-scale fire testing to collapse of steel stiffened plate structures under lateral patch loading (part 2) – with passive fire protection. Ships Offsh Struct. 16(3):243–254; Ryu MG, He KH, Lee DH, Park SI, Thomas G, Paik JK. 2021. Finite element modeling for the progressive collapse analysis of steel stiffened-plate structures in fires. Thin-Walled Struct. 159:107262). Specifically, this study demonstrates that the computational models developed in the earlier studies can be applied to the analysis of the heat transfer and fire-induced progressive collapse behaviour of the topside structures of a ship-shaped offshore installation. To this end, a hypothetical VLCC-class floating, production, storage and offloading (FPSO) unit hull structure is considered, and transient thermal elastic-plastic large-deformation finite element models are used. The novelty of this study and its contribution to industry are the development of a practical procedure to ensure the fire safety of large-scale steel-plated structures with complex geometries. [ABSTRACT FROM AUTHOR]

According to the architectural requirements, the roof structure of a large-span gymnasium adopts the suspen-dome structure. In the scheme selection stage of the pre-stressed cable-strut system at the bottom part of the suspen-dome structure, a Levy-type scheme and a Loop-free scheme are established. The finite element models are established, and the static analysis under the design loads, the whole process analysis of load-displacement, and the dynamic response analysis after accidental cable break are carried out. The architectural expression of the two schemes are discussed. The component material consumption, the structural stiffness, the tension distribution characteristics, and the static bearing capacity of the two schemes are discussed. The failure mode and the progressive collapse resistance of the two schemes after accidental cable break are also discussed. The results show that the Loop-free scheme requires significantly less in terms of component material consumption than the Levy-type scheme. The static failure mode of the two schemes is strength failure, but the Loop-free scheme has greater bearing capacity. The Loop-free scheme has greater structural stiffness, lower cable forces, and uniformly distributed cable forces in each layer, and lower stress on the top reticulated shell members. Neither of the two schemes experience progressive collapse after accidental cable break. Due to the rupture in the loop cable of the Levy-type scheme, the rigidity of the rear region decreases greatly, and the cable force loss is large. On the contrary, internal force redistribution occurs in the Loop-free cable scheme and the cable force loss is not obvious, hence the progressive collapse resistance is better than that of the Levy-type scheme. [ABSTRACT FROM AUTHOR]

Corrosion damage is a serious problem in steel structures. The cross-sectional loss in the structural members due to corrosion reduces the load-carrying capacity of the members and the stability of their structures. In this study, the main reasons for the collapse of three steel sports infrastructure facilities after moderate snowfall were investigated by conducting field observations and detailed numerical analyses. Finite element models of the structures were developed by considering the effects of different rafter systems and corrosion damage at their columns' support regions. The load-carrying capacity ratios and stress distributions of the structural members were determined under the effect of the snow load at the time of the collapse. The analysis results were consistent with the damage modes observed during site inspections. The snowfall was not the primary cause of the collapse; however, the section and joint losses due to excessive corrosion, improper erections, and discrepancies between the design project and the as-built project were the main reasons for the collapse. [ABSTRACT FROM AUTHOR]

Masonry arch bridges are highly vulnerable to floods and particularly to scour, as demonstrated by the many collapses that regularly occur in Europe. Scour levels that do not directly cause the collapse of a bridge may result in a significant reduction of their capability to withstand traffic loading. Thus, research on the performance of masonry arch bridges under combined scour and traffic loading, and their structural robustness, is of paramount importance. This study evaluates the behaviour of masonry arch bridges subjected to scour and traffic loading by analysing a representative case study with a three-dimensional finite element model developed in Abaqus according to a macro-modelling approach. Traffic load is selected in accordance with different code-based models, including those provided by Italian guidelines for safety assessment of existing bridges. The scouring process is imposed through the progressive removal of elements at the foundation level. Displacements and internal stress distributions for different bridge components are recorded and the capacity of the masonry bridge is estimated under increasing traffic load for different scour levels. Results are obtained in terms of both local and global response parameters to provide useful information on threshold levels for bridge safety and monitoring. The sensitivity of the bridge structural performance to material properties and traffic load position is also assessed. The study results can be useful to inform the decisions to be taken by bridge stakeholders (e.g. close bridge, limit traffic, keep bridge open) based on scour and/or structural response measurements. • Multi-hazard assessment of masonry arch bridges under scour and traffic loading. • Incorporation of traffic load models from Eurocode 1 and recent Italian guidelines. • Multi-scale assessment based on 3D FE macro-modelling and nonlinear static analyses. • Robustness to scour-induced damage based on residual traffic-load capacity. • Derivation of scour-induced damage thresholds for progressive collapse prevention. [ABSTRACT FROM AUTHOR]

A series of dynamic progressive collapse tests using the uniformly distributed load (UDL) was conducted, to analyze the robustness of three precast concrete (PC) beam–column assemblies using dry connections of top-and-seat angles (TSA-D), strengthened top-and-seat angles (STSA-D), and high-ductility reinforcement (DSTSA-D), under a middle column removal scenario. Finite element (FE) models were also developed to accurately simulate the collapse process. Based on the tests and FE models, comparative studies were conducted on dynamic and static collapse responses of the PC assemblies with identical configuration, loading regime, and boundary conditions. The results showed that: the horizontal reaction force developments were similar under dynamic and static collapse scenarios; under dynamic collapse scenarios, the initial stiffness of the PC assemblies increased due to the strain rate effect, while the peak vertical reaction forces under the compressive arch action (CAA) were smaller than those under static collapse scenarios, attributed to dynamic damage; under both dynamic and static collapse scenarios under UDL, the beam deformed in a downward convex curved shape, with local material deformation becoming more concentrated under dynamic collapse scenarios. An energy-based method for calculating dynamic collapse resistance was evaluated and revised: 1) the traditional method, which converts static responses from static analysis into dynamic responses was found to underestimate the resistance under small deformations due to neglecting the strain rate effect, and to overestimate ultimate resistance by ignoring dynamic damage; 2) by using dynamic vertical reaction forces instead, a more accurate prediction of the dynamic collapse resistance was achieved with a single dynamic collapse analysis. Additionally, dynamic amplification factors for the PC assemblies were calculated based on FE models and static test results providing basic knowledge in whole PC structural level research. • Dynamic progressive collapse tests under uniformly distributed load. • High-fidelity finite element models simulating dynamic collapse of PC assemblies. • Comparison between dynamic and static collapse responses of PC assemblies. • Dynamic collapse resistance considering strain rate effect and dynamic damage. • Dynamic amplification factors (DAF) for simplified collapse resisting design. [ABSTRACT FROM AUTHOR]

• Progressive collapse tests based on four 3D substructures are carried out, including a loss of corner column and edge column. • The effect of the slab and secondary beam on the load distribution mechanism is investigated based on the finite models. • Theoretical models considering the effect of secondary beam and torsion of the primary beam of bearing capacity are proposed. An investigation on progressive collapse for three-dimensional RC structures was presented in this paper, based on a series of experimental tests and numerical analysis. The crack pattern and load–displacement curves were compared and discussed according to three single-story specimens under the loss of corner column and a two-story specimen under the loss of edge column. Experimental results show that flexural action is the main resistance mechanism for specimens whether the removal of corner or edge column. Moreover, the effect of the slab and secondary beam on the loading transfer mechanism was studied based on finite element model with various scenarios established by ABAQUS. The numerical results had a well agreement with the experimental results. FEA results indicated that the phenomenon of uneven distribution of loads can be improved due to the existence of slab and secondary beam. Finally, the corresponding analytical models considering the effect of secondary beam and torsion of primary beam with various scenarios were proposed to predict progressive collapse resistance. [ABSTRACT FROM AUTHOR]

This work aims to clarify the causes leading to the structural collapse of the garage of a residential development located in Santander, Spain, in 2020. Visual inspections of the collapsed area were carried out to establish the first hypotheses about the collapse. Subsequently, the materials, geometry and acting loads were studied to compare them with the original project. The main conclusion was that the slab was subjected, in the area where the collapse began, to gravity loads of 34 kN/m 2 when it was designed to support 15 kN/m 2. Then, structural verifications were performed in accordance with EHE-08 and Eurocode 2, in force during project design, to identify the failure mechanism(s) that caused the progressive collapse of the structure. Unacceptable safety factors were observed for punching shear, which was the main failure mechanism. Punching was aggravated by cavities detected in the concrete, which caused both a decrease in the slab strength (lower effective depth of the slab) and an increase in the stresses in the compression struts of about 20 % to 30 %, which considerably reduced the punching safety levels. This calculation was carried out by means of a finite element analysis with SAP2000. The assessment of this type of defect, very common during the execution phase, is not well developed either from a theoretical or regulatory point of view. This paper proposes, as a corrective measure, the inclusion both in the European and National Standards of a mandatory inspection procedure based on Ground Penetration Radar or ultrasounds, during the execution phase, to detect and correct this type of defect, not detectable by visual inspection. Finally, a bending and cracking analysis were also conducted, giving values of the corresponding safety factors of less than unity. Therefore, they also contributed to both the progressive loss of strength of the slabs and the final punching failure. These last two causes are also crucial to understand why the collapse occurred 15 years after its commissioning. • Two concomitant causes were established: excess load on slabs and concrete defects. • A FEM analysis was runed to determine stress increments due to concrete cavities. • Punching safety coefficients not admissible, even for non-factored loads. • The punching shear fracture-bending-slab cracking interaction was assessed. • A single column could cause the collapse of 475 dwellings and 500 parking spaces. [ABSTRACT FROM AUTHOR]

• Novel framework combining OpenSees and VBA Excel Tool for efficient bracing and collapse assessment. • Practical code-based approach overcoming limitations of complex finite element methods. • Automatic plastic hinge display and UFC-based checks for quick identification of weaknesses. • Actionable recommendations for collapse prevention and improved structural analysis practices. Braced frames are among the most effective systems for resisting progressive collapse; however, determining the optimal bracing system remains challenging. Evaluating different bracing systems in this study was simplified using VBA programming tools and a flowchart that complied with the Unified Facilities Criteria (UFC)regulations (chapter 5). Applying control processes and automated VBA programming tools was beneficial for examining plastic hinges and guaranteeing adherence to the Unified Facilities Criteria (UFC)Design Strategies for Preventing Progressive Collapse in Building Structures.The study examined several types of braced frames, such as CBF and EBF, and found that the inverted V-braced systems (CBF and EBF) were the most efficient. They reduced the amount of vertical movement and dispersed the stresses on the remaining linked parts. Although there was a substantial vertical displacement, all beams and columns showed a decrease in overall force. The absence of a bracing system in the frame led to a violation of the regulatory criteria outlined in the control flowchart. The remaining structural systems exhibited exceptional performance. [ABSTRACT FROM AUTHOR]

The use of corrugated web beams in civil buildings is gradually increasing. Therefore, the effects of web openings on the collapse resistance of corrugated web beam–column structures must be investigated. This study conducts static loading tests on standard corrugated web (SCW) and open corrugated web (OCW) specimens with a failed middle column. The web openings have minimal effect on the preliminary bearing capacity of the OCW specimen compared to that of the SCW specimen. The specimens show similar internal force development trends, deformation zones in the webs at 45° to the flange, and tensile flange ruptures near the failed column. The deformation of the web openings delays the formation of the deformation zone in the connection area. The maximum load-bearing capacity and failure displacement of the OCW specimen are 46.5% and 32% larger than those of the SCW specimen, respectively, which indicates that openings in the corrugated web can improve the collapse resistance of the substructure. A finite element model is used to analyze the effects of various opening parameters, such as the diameter-to-height ratio, margin, and opening eccentricity on the collapse resistance of the structure. The reasonableness of the numerical model is verified by comparing the results of numerical simulations and practical experiments. The diameter-to-height ratio is positively correlated with the collapse resistance of the substructure. To optimize the shear capacity of the beam, the diameter-to-height ratio should be <0.5. When the margin is <1.8 times the height of the beam, the collapse resistance of the structure increases with the increase of the distance between the opening edges. Therefore, a suitable margin is 1.3–1.8 times the beam height. Openings in the pressure zone negatively affect the collapse performance of the substructure. Therefore, openings should be eccentricity-free or located in the tensile zones. The results of this study can be used as a reference for future projects. • A half scale test is carried out on the beam-column substructure with corrugated web openings. • The continuous collapse behavior of the surrounding substructure under the failure of the middle column is investigated. • The finite element numerical model was established to verify its correctness. • Simulating the collapse resistance performance of corrugated web beam-column structures under different pore factors. [ABSTRACT FROM AUTHOR]

Progressive collapsing foot deformity results from degeneration of the ligaments and posterior tibial tendon (PTT). Our understanding of the relationship between their failures remains incomplete. We sought to improve this understanding through computational modeling of the forces in these soft tissues. The impact of PTT and ligament failures on force changes in the remaining ligaments was investigated by quantifying ligament force changes during simulated ligament and tendon cutting in a validated finite element model of the foot. The ability of the PTT to restore foot alignment was also evaluated by increasing the PTT force in a foot with attenuated ligaments and comparing the alignment angles to the intact foot. We found that failure of any one of the ligaments led to overloading the remaining ligaments, except for the plantar naviculocuneiform, first plantar tarsometatarsal, and spring ligaments, where removing one led to unloading the other two. The combined attenuation of the plantar fascia, long plantar, short plantar, and spring ligaments significantly overloaded the deltoid and talocalcaneal ligaments. Isolated PTT rupture had no effect on foot alignment but did increase the force in the deltoid and spring ligaments. Moreover, increasing the force within the PTT to 30% of body weight was effective at restoring foot alignment during quiet stance, primarily through reducing hindfoot valgus and forefoot abduction as opposed to improving arch collapse. Our findings suggest that early intervention might be used to prevent the progression of deformity. Moreover, strengthening the PTT through therapeutic exercise might improve its ability to restore foot alignment. [ABSTRACT FROM AUTHOR]

This paper presents a study on the modelling approaches for column loss scenarios using software that is widely available to structural engineers worldwide, with the goal of providing practical guidance to designers faced with the need or the opportunity to perform progressive collapse analyses. The presented study leverages recent experimental results on column removal in a composite frame obtained at the University of Trento. Comparisons between experimental data, results of high‐definition finite element analyses, and the simulation results obtained using commercially available software are performed and conclusions are drawn based on the modelling approach used. Furthermore, a parametric study on various column loss scenarios in a prototype building is conducted and the results are compared with highdefinition model results in literature. It is concluded that the proposed modelling approach can be successfully used in practical cases, with results that are quite satisfactory both at the local and at the global level. [ABSTRACT FROM AUTHOR]

The swimming pool on large passenger ships creates challenges for structural designers. Designers have to take into account the effect of the large opening and its reinforcement on the strength of deck structures. In this paper, experimental and finite element analyses are presented on the ultimate compressive strength of two double-deck structures with a large opening on the upper deck. Buckling collapse behaviour of the upper and lower decks are investigated during the progressive collapse of double-deck structures. Comparison of the experimental results shows that the structural reinforcement for deck opening increases about 29% the ultimate compressive strength and changes the overall buckling and collapse behaviour of double-deck structures. The finite element analysis quantifies the effect of reinforcing large openings to improve the structural strength of perforated structures. A design methodology is put forwards for reinforcements based on equivalent buckling and ultimate strength concept. [ABSTRACT FROM AUTHOR]

The influence of masonry infill walls on the progressive collapse performance of reinforced concrete (RC) frame structures was investigated in this paper, using a nonlinear dynamic analysis approach. Based on ANSYS/LS-DYNA finite element software, two finite element models of RC frame structures with and without masonry infilled walls were established. Then, the collapse modes of the two RC frame structure models were analyzed for different scaled distance blast loads, different locations of column damage, and different span numbers. The results show that with the increase of explosive amount, the collapse degree of the structure is more serious in the same time. Under the condition of destroying the outermost central column, the degree of progressive collapse of the RC frame model with infilled walls in the same time is lower than that of the RC frame model without infilled walls. The RC frame model with infilled walls is more resistant to collapse when the outermost side columns are damaged. With the increase of span number, the structure is more likely to be damaged and collapsed. [ABSTRACT FROM AUTHOR]

This research employed extensive numerical analyses to locate the weak areas and determine the structural issues critical to preventing the spread of collapse. As a result, three specimens were tested using scaled models of strengthened and unstrengthened steel beam–column joint assemblies. The data were utilized to verify numerical models. One simple shear joint from the three experimental assemblies was used as the control specimen (unstrengthened joint). The second was a bolted steel beam–column joint utilized as a reference specimen to reflect the ideal beam–column joint generally employed in intermediate moment-resisting frames in seismic zones worldwide. Similar to the control, the third specimen (strengthened joint) had two side plates welded together to strengthen the connection site. Numerical finite element models were developed using ABAQUS (2020) software to extensively investigate the behavior of steel frame assemblies before and after upgrading. The FEM matrix comprised 17 specimens with varying parameters, including plate thickness, steel grade, a joint between the beam flange-strengthening plates, and a column that was either welded or not welded. The effectiveness of the strengthening techniques was established by comparing the mode of failure and load–displacement characteristics of the investigated specimens. The results indicate that the average increase in peak load due to a change in plate thickness for grades A36 and A572 is approximately 22% and 8%, respectively. Plates made of A572 steel increase peak load by 30%. All strengthened specimens attained catenary action, mitigating the possibility of progressive collapse. [ABSTRACT FROM AUTHOR]

When a concrete slab is excessively loaded due to an accidental event, compressive membrane action can be activated in order to generate an alternative load transfer to the remaining supports, which can considerably enhance the load‐carrying capacity. This can increase the structural reliability of the components, delay or even prevent a progressive collapse and consequently increase the robustness of concrete structures. Although the beneficial effects of compressive membrane action in reinforced concrete slabs have been recognized for decades, only limited research has been focusing on this effect in prestressed concrete members, like hollow core slabs. Therefore, a novel real‐scale test set‐up has been developed in order to assess this phenomenon in real‐scale hollow core slabs. The results indicate that, despite the presence of the large hollow cores, compressive membrane action can significantly improve the load‐carrying capacity of hollow core slabs under excessive loading. In parallel, a numerical finite element model has been established in order to model the structural behavior (i.e., compressive membrane action) as per the investigated test program. The model was able to correlate the results from the experiments very well, and emphasized the large influence of the concrete tensile strength on the ultimate failure load of concrete hollow core slabs in compressive membrane action. [ABSTRACT FROM AUTHOR]

The crashworthiness of composite tubes is widely examined for various types of FRP composites. However, the use of hybrid composites potentially enhances the material characteristics under impact loading. In this regard, this study used a combination of unidirectional glass–carbon fibre reinforced epoxy resin as the hybrid composite tube fabricated by the pultrusion method. Five tubes with different length aspect ratios were fabricated and tested, in which the results demonstrate "how structural energy absorption affects by increasing the length of tubes". Crash force efficiency was used as the criterion to show that the selected L/D are acceptable of crash resistance with 95% efficiency. Different chamfering shapes as the trigger mechanism were applied to the tubes and the triggering effect was examined to understand the impact capacity of different tubes. A finite element model was developed to evaluate different crashworthiness indicators of the test. The results were validated through a good agreement between experimental and numerical simulations. The experimental and numerical results show that hybrid glass/carbon tubes accomplish an average 25.34 kJ/kg specific energy absorption, average 1.43 kJ energy absorption, average 32.43 kN maximum peak load, and average 96.67% crash force efficiency under quasi-static axial loading. The results show that selecting the optimum trigger mechanism causes progressive collapse and increases the specific energy absorption by more than 35%. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abnormal loads can produce localized damage that can eventually cause progressive collapse of the whole reinforced concrete (RC) structure. This might have devastating financial repercussions and cause numerous severe casualties. Numerical simulation, using the finite element method (FEM), of the consequences of abnormal loads on buildings is thus required to avoid the significant expenses associated with testing full-scale buildings and to save time. In this paper, FEM simulations, using ABAQUS software, were employed to investigate the progressive collapse resistance of the full-scale three-dimensional (3D) beam–slab substructures, considering two concrete mixes, namely: normal concrete (NC) and rubberized concrete (RuC) which was made by incorporating crumb rubber at 20% by volume replacement for sand. The FEM accuracy and dependability were validated using available experimental test results. Concrete and steel material non-linearity were considered in the FE modelling. The numerical study is extended to include eight new models with various specifics (a set of parameters) for further understanding of progressive collapse. Results showed that slabs contribute more than a third of the load resistance, which also significantly improves the building's progressive collapse resistance. Moreover, the performance of the RuC specimens was excellent in the catenary stage, which develops additional resilience to significant deformation to prevent or even mitigate progressive collapse. [ABSTRACT FROM AUTHOR]

The contribution of each of the ligaments in preventing the arch loss, hindfoot valgus, and forefoot abduction seen in progressive collapsing foot deformity (PCFD) has not been well characterized. An improved understanding of the individual ligament contributions to the deformity would aid in selecting among available treatments, optimizing current surgical techniques, and developing new ones. In this study, we evaluated the contribution of each ligament to the maintenance of foot alignment using a finite element model of the foot reconstructed from computed tomography scan images. The collapsed foot was modeled by simulating the failure of all the ligaments involved in PCFD. The ligaments were removed one at a time to determine the impact of each ligament on foot alignment, and then restored one at a time to simulate isolated reconstruction. Our findings show that the failure of any one ligament did not immediately lead to deformity, but that combined failure of only a few (the plantar fascia, long plantar, short plantar, deltoid, and spring ligaments) could lead to significant deformity. The plantar fascia, deltoid, and spring ligaments were primarily responsible for the prevention of arch collapse, hindfoot valgus, and forefoot abduction, respectively. Moreover, to produce deformity, a considerable amount of attenuation in the spring, tibiocalcaneal, interosseous talocalcaneal, plantar naviculocuneiform, and first plantar tarsometatarsal ligaments, but only a small amount in the plantar fascia, long plantar, and short plantar ligaments was needed. The results of this study suggest that the ability of a ligament to prevent deformity may not correlate with its attenuation in a collapsed foot. [ABSTRACT FROM AUTHOR]