Eccentric Compression Loading Research Articles

Crack growth life calculation approach of surface cracked landing gear strut under eccentric compression load by bulging effect

The landing gear strut is mainly subjected to eccentric compression load during service, and the calculation of its stress intensity factor is often considered as a challenge to calculate the surface crack growth life. Based on the bulging effect, we modify the stress intensity factor of the surface cracked cube, and obtain the stress intensity factor formula of the surface cracked strut. It calculates the stress intensity factor by using geometric characteristics and load characteristics, and calculates the crack growth life without meshing finite element model. In the study of surface fatigue crack growth of steel strut under eccentric compression load, the proposed approach to calculate the crack growth life of surface cracked strut is proved to be feasible. The method is simple and conservative.

Non-linear analysis of the postbuckling behaviour of eccentrically compressed composite channel-section columns

This analysis investigates short thin-walled channel-section columns made of CFRP laminate. Columns with four multi-ply composite layups were tested, each layup having 8 plies symmetric to the midplane. The columns were subjected to compressive loads, including an eccentric compressive load applied relative to the centre of gravity of their cross-section. The study involved performing a nonlinear analysis of the structures with implemented geometric imperfections that reflected the first buckling mode. The nonlinear analysis was conducted using the Tsai–Wu criterion to determine effort of the composite material. The computations were run until the critical parameter in the Tsai–Wu criterion was reached, which made it possible to describe the failure initiation mechanism in the composite material. Experiments were conducted to detect first signs of damage to the composite material by the acoustic emission method (AEM). Experimental results were used to determine postbuckling equilibrium paths of the numerical models. The equilibrium paths were then compared with the experimental characteristics of real structures. The numerical and experimental results showed satisfactory agreement. That confirmed that the developed numerical models were suitable for estimating the postbuckling behaviour of composite structures depending on the amplitude of compressive load eccentricity.

Measuring compressive loads on a ‘smart’ lumbar interbody fusion cage: Proof of concept

There are several complications associated with lumbar interbody fusion surgery however, pseudarthrosis (non-union) presents a multifaceted challenge in the postoperative management of the patient. Rates of pseudarthrosis range from 3 to 20 % in patients with healthy bone and 20 to 30 % in patients with osteoporosis. The current methods in post-operative follow-up - radiographs and CT, have high false positive rates and poor agreement between them. The aim of this study was to develop and test a proof-of-concept load-sensing interbody cage that may be used to monitor fusion progression. Piezoresistive pressure sensors were calibrated and embedded within a polyether ether ketone (PEEK) interbody cage. Silicone and poly (methyl methacrylate) (PMMA) were inserted in the graft regions to simulate early and solid fusion. The load-sensing cage was subjected to distributed and eccentric compressive loads up to 900 N between synthetic lumbar vertebral bodies. Under maximum load, the anterior sensors recorded a 56–58 % reduction in pressure in the full fusion state compared to early fusion. Lateral regions measured a 36–37 % stress reduction while the central location reduced by 45 %. The two graft states were distinguishable by sensor-recorded pressure at lower loads. The sensors more effectively detected left and right eccentric loads compared to anterior and posterior. Further, the load-sensing cage was able to detect changes in endplate stiffness. The proof-of-concept ‘smart’ cage could detect differences in fusion state, endplate stiffness, and loading conditions in this in vitro experimental setup.

Predictive models of behavior and capacity of FRP reinforced concrete columns

This paper proposes a new model for predicting the axial capacity and behavior of Fiber Reinforced Polymerreinforced concrete (FRP-RC) columns using a promising variant of Genetic Expression Programming (GEP). Current design codes, such as the ACI 440.1R-15 and the Canadian Code CSA S806, disregard the compressive contribution of FRP bars when used in compression members. The behavior of concentrically short FRP-RC columns has been widely investigated in the past few years; however, limited research has been dedicated to investigating the effect of load eccentricity and the slenderness ratio of FRP-RC columns. In addition, the methodologies adopted for including the effect of column slenderness remain a subject of debate, as no solid conclusions are withdrawn in this regard. In this paper, the experimental results of FRP-RC columns are gathered from the literature and used to formulate two GEP models to predict the axial capacity based on load eccentricity. The experimental data includes columns reinforced with different FRP types and subjected to concentric and eccentric axial compressive loads. In addition, the database comprises short and slender columns. The proposed GEP models are functions of concrete compressive strength, longitudinal reinforcing bars ratio, FRP bars elastic modulus, eccentricity level, and column dimensions. For the aim of comparison, a preliminary evaluation of previously suggested empirical equations/models for estimating the axial capacity of FRP-RC columns was carried out over the collected database. The proposed models showed superior accuracy in axial capacity prediction with coefficients of determination R2 equals to 0.978 and R2 equal to 0.992 for eccentric and concentric axial load, respectively. The proposed models were found to give reliable estimates of the axial capacity of columns reinforced with FRP longitudinal bars. Finally, a parametric study to evaluate the effect of each variable on the proposed models was conducted.

Failure characteristics of cold-formed steel built-up sections with web stiffeners under axial and eccentric compression

To seek high load-carrying capacity members, built-up sections of Cold-formed steel (CFS) have been the popular choice. While most of the studies focused on the built-up sections with plain channel sections (with or without lips), few studies have been reported for the built-up sections with channel sections with web stiffeners, particularly also considering the eccentric loading and web openings. This paper presents a total of 44 new experimental results comprising 22 built-up sections with V-stiffeners and 22 with Σ-stiffeners of four different member lengths under the axial and eccentric compression loading to reveal the potential failures and load-carrying capacity of these built-up sections. The measurements of initial geometric imperfections and tensile coupon tests were conducted before compression tests. Following the test program, the experimental results provided the details of the buckling behavior and failure modes and a set of load response curves. The failure modes and impact of a variety of member parameters on the buckling behaviors and axial strengths were analyzed and discussed. The study herein revealed the failure characteristics of these built-up sections under axial and eccentric loading and provided preliminary test results for further expansion and computational model development.

Experimental investigation on eccentric compression behavior of FRP-confined concrete-encased cross-shaped steel columns

FRP-confined concrete-encased cross-shaped steel column (FCCSC), composed of an outer square glass-fiber-reinforced plastic (GFRP) tube, the internal cross-shaped steel, and the filled concrete, is a novel type of composite column. Eleven square FCCSCs were tested subject to eccentric axial compression load. The influence of eccentricity and slenderness ratio was evaluated and investigated. The test results showed that both the axial load-bearing capacity and lateral confinement efficiency of FRP tube reduced with the increase of eccentricity and slenderness ratio. The maximum reduction in axial load-bearing capacity was up to 50.7 % and 71.1 %, with the eccentricity varying from 0 mm to 50 mm and 100 mm, while the maximum reduction was about 18.1 % and 27.5 % when slenderness ratios increased from 10.44 to 20.87 and 34.79, respectively. The ductility of eccentric compressed FCCSCs can be evaluated by combined strain. It is indicated that short columns exhibited the best ductility, and the ductility increased with the increase of eccentricity. However, the ductility of slender columns reduced with the increase of eccentricity. Based on the test results, the experimental axial force (N)-moment (M) interaction curve of FCCSCs was obtained, and the balanced failure between compression and tension failure mode was recommended.

Compressive Performance of RC Columns Strengthened with High-Strength Stainless Steel Wire Mesh-ECC under Small Eccentric Compression Load

In this research, a novel composite material, high-strength stainless steel wire mesh-ECC, is proposed and designed to strengthen RC columns. The small eccentric compressive performance of RC columns strengthened with high-strength stainless steel wire mesh-ECC was investigated through compression tests and compared with unstrengthened columns and RC columns strengthened with ECC. Six columns were designed and tested, and the test parameters contained different strengthened methods, eccentricity ratios, and reinforcement ratios of longitudinal high-strength stainless steel strand. The failure patterns, load-carrying capacity, strain of concrete/ECC and reinforcement, etc., were analyzed based on the test results. The high performance of the high-strength stainless steel wire mesh-ECC and the advantages of the proposed strengthened method, including good ductility, excellent crack-control ability and satisfactory failure patterns, were demonstrated when compared with the specimens strengthened with ECC. The stainless steel wire mesh-ECC-reinforced layer can have effective constraint columns and can control the crack ability. The cracking load of the stainless steel wire mesh-ECC-reinforced column is 100.0–113.3% higher than that of the unreinforced column, and the peaking load is 99.8–108.0% higher than that of the unreinforced column. The stainless steel wire mesh-ECC-reinforced column shows good ductile failure characteristics, and compared with the unreinforced column, the ductility is increased by 75.6–77.8%. Based on the analysis of the strain distribution and failure patterns, the mechanical mechanism of RC columns strengthened with the novel composite material high-strength stainless steel wire mesh-ECC is proposed.

Sensitivity of Compressed Composite Channel Columns to Eccentric Loading.

This study investigated short thin-walled channel columns made of carbon/epoxy laminate. Columns with two multi-ply composite layups [0/45/−45/90]s and [90/−45/45/0]s were tested, with each layup having eight plies symmetric to the midplane. The columns were subjected to compressive loads, including an eccentric compressive load applied relative to the center of gravity of their cross-section. Simple support boundary conditions were applied to the ends of the columns. The scope of the study included analyzing the effect of load eccentricity on the buckling mode, bifurcation load (idealized structure), and critical load (structure with initial imperfections). The critical load for the actual structure was determined with the use of approximation methods, based on experimental postbuckling equilibrium paths. In parallel with the experiments, a numerical analysis was conducted using the finite element method and Abaqus® software (Dassault Systèmes, Vélizy-Villacoublay, France). The first stage of the numerical analysis consisted of solving an eigenproblem, in order to determine the mode of the loss of structural stability and to calculate the bifurcation loads for structures under axial and eccentric compression. The second stage of the numerical analysis involved examining the non-linear state of pre-deflected structures. Numerical postbuckling equilibrium paths were used to estimate the critical loads with an approximation method. The experimental results were used to validate the numerical models. This made it possible to determine the effect of compressive load eccentricity on the buckling mode and critical load of the tested structures. The results confirmed that compressive load eccentricity had a significant impact on the load-carrying capacity in the postbuckling range. This may potentially lead to premature damage to composite materials and, ultimately, to a reduced load-carrying capacity of structures.

Experimental and analytical study on eccentric compressive behavior of concrete columns strengthened with high-strength reinforcement of HRB600

This study examines the influence of initial eccentricity, volume stirrup ratio, and the strength of longitudinal reinforcement and stirrup on the eccentric compressive performance of concrete columns strengthened with HRB600-high-strength-reinforcement. Ten concrete columns are tested under eccentric compression. The compressive mechanism evaluates and compares the failure characteristics, load-deformation curve, reinforcement strain, and eccentric compression performance. As part of the numerical study, the finite element modeling of OpenSees is used to predict the response of HRB600 specimens under eccentric compressive loading, and parametric analysis is subsequently conducted. The research findings illustrate that HRB600 longitudinal reinforcement can yield in tension and compression with large eccentricity when approaching the ultimate bearing capacity state. After normal strength longitudinal reinforcement is supplanted, the reinforcement amount is saved. Lastly, semi-empirical models have been proposed to predict the compressive performance of concrete columns with high-strength reinforcement.

Strength of Composite Columns Consists of Welded Double CF Sigma-Sections Filled with Concrete—An Experimental Study

In-filled tubes section is a very successful configuration for axially loaded members such as columns and struts. Steel shell tube filled with concrete has many advantages, such as eliminating the need for shuttering, reinforcement bars or ties besides increasing both flexural and axial capacities and enhancing the ductility. The main disadvantage of in-filled tubes is the need for a shell thick enough to prevent the local buckling and hence the local decomposition. Previous studies tried to solve this problem using intermediate stiffeners or shear connectors. This research presents another approach to solve this problem using double cold-formed sigma-sections (face to face) as steel shell tubes. Sixteen specimens with different lengths, cross section dimensions and shell thicknesses were tested under both concentric and eccentric compression loads. Ultimate capacities, lateral deformations and normal strains were recorded. The theoretical capacities were calculated using AISC-LRDF-94, EN-1994-04 and CSI-COL software considering full composite action, and the deviations from the experimental results were 24%, 24% and 13%, respectively.

Experimental and analytical assessment on rubberized concrete interlocking grouted masonry walls under eccentric loading

In this study, the concept of interlocking masonry is modified by introducing waste materials, fly ash (FA) and crumb rubber (CR), to overcome the issues of mortared walls and conventional interlocking walls. Therefore, this research is aimed to investigate the behavior of rubberized concrete interlocking grouted masonry walls (RCIGMWs) subjected to eccentric compression loading experimentally. Twelve RCIGMWs of size 1260 mm height × 625 mm width × 125 mm thickness were constructed, by stacking RCIBs in running bond on top of one another without the use of mortar layers, however, the center cores (holes) of the wall panels were filled by pouring the concrete grout into. RCIGMWs were then tested under four axial compression eccentric loading levels including e=0, e=t/6, e=t/3, and e=t/2.5 where the top of the wall panels was considered for eccentricity while the end was maintained flat as a fixed. The bottom support was fixed while the upper end was free. The structural responses including the efficiencyof the walls, axial displacement and lateral deformation, and failure mechanisms were investigated. The experimental findings show that higher compressive eccentricities adversely impacted the behavior responses of RCIGMWs. Under eccentricities greater than kern distance, walls suffered significant loss of their load-bearing capacity. Moreover, higher lateral deflection was recorded at higher eccentricity levels as a result of the developed wall’s bending moment. Vertical splitting failure was observed between the webs and brick shells, which was followed by localized spalling. A global buckling was formed at higher eccentricity levels where the wall bent and the dry bed joint at the upper height of the wall opened and failed prematurely. Analytically, the EC-6 and ACI-530 are able to calculate the load-bearing capacity of the RCIGMWs, however, they tend to underestimate it with increasing the eccentricity while BS 5628–1 provides approximately 90 % precision.

The Eccentric Compression Performance of Spirally Stiffened Thin-Walled Square Concrete-Filled Steel Tubular Laminated Composite Members

To enhance the local buckling resistance of thin-walled steel pipes and enhance their fire and corrosion resistance, a new spirally stiffened thin-walled square concrete-filled steel tubular laminated composite member with transverse ribs is proposed. Through the four forms of combined members for eccentric pressure testing, it was found that: ordinary thin-walled steel pipe concrete drum buckling is more severe; with spiral ribs, the buckling is limited between the stiffening ribs; and the deformation is significantly reduced. By addressing the problem of cooperative work between the inner and outer structural layers of new components, it was found that, after setting constraints such as steel bars, the integrity of the two can be ensured, and the stress performance is significantly improved; compared to ordinary steel pipe concrete, the load-carrying capacity is 17.9% higher, and the deformation capacity is roughly equivalent. Spiral ribs as a new form of spatial restraint, in addition to increasing the local bending stiffness, manifest an overall restraint role in limiting lateral deformation of the steel pipe, whereas the role of vertical stiffness is insignificant. Based on test evidence, the influences of the width to thickness ratio of spiral ribs and pitch were determined, and reasonable structural measures for the members were given. Through the N–M relationship curve, the limit of damage in compression and tension under eccentricity was obtained at an eccentricity of about 0.9. Finally, a method for calculating the eccentric compressive ultimate load capacity of this new composite member was proposed.

Experimental and theoretical study on concrete-filled T-shaped steel tubular columns under uniaxial eccentric compression

This paper presents an experimental and theoretical study on concrete-filled T-shape steel tubular (CFTST) beam-columns. Four full-scale slender beam-columns with slenderness ratio of 33.7–39.1 were tested under uniaxial eccentric compressive loads. In addition, three stub columns with the same cross-sections were axially compressed to investigate the confinement effect. Failure mode, axial displacement, lateral deflection, axial strain and hoop strain were obtained to understand the structural behavior of CFTST beam-columns. For beam-columns bended about the symmetric axis, torsion was not observed but a slight rotation of the neutral axis that was no longer parallel to the centroid axis was found by analyzing the experimental results. A fiber element model for CFTST beam-columns was developed and verified for parametrical analysis. The effects of key parameters, such as material properties, cross-section dimensions, loading angle and slenderness ratio, on the behavior of stub and slender beam-columns were investigated. Finally, theoretical models were proposed to estimate the interaction curve and the load-carrying capacity of CFTST beam-columns. The prediction matches well with the experimental results.

Experimental investigation and design of sheathed LSF wall panels under eccentric axial compression

Sheathing is an important component in cold-formed Light gauge Steel Framed (LSF) walls and floors. LSF wall studs with one- or two-sided sheathing have been shown to have an increased ultimate compression capacity since the sheathing is capable of restraining global buckling modes. Although sheathing’s contribution has been ignored in the past, current design standards include provisions for the consideration of sheathing in the design of LSF walls. Australian cold-formed steel standard allows the designers to consider sheathing’s lateral and rotational restraints to studs, but it does not quantify the restraint values to be used. A recent report of American Iron and Steel Institute (AISI RP 13-1) provides suitable design guidelines for LSF walls with single sheathing, non-identical sheathing and different fastener spacings subject to axial compression, however, they have not been validated for LSF walls under combined compression and bending actions. An experimental investigation on LSF wall panels subject to combined actions due to eccentric loading was conducted in this research to understand the effects of loading eccentricity on sheathed LSF wall panels. Fifteen single stud wall panels of 1.5 m and 3.0 m height made of lipped channel studs were tested under concentric and major axis eccentric compression loading. Effects of sheathing and loading eccentricity on the failure modes and ultimate capacities were evaluated, and importantly, the suitability of the sheathing braced design guidelines in AISI RP 13-1 was investigated. The results showed that the use of the spring-based restraints recommended in AISI RP 13-1 with the linear interaction equation provides improvements in predicting the capacity of sheathed walls subject to eccentric compression.

In-situ imaging of flexure-induced fracture in tape-laminate composites using high-resolution X-ray computed tomography

This study presents development of an in-situ flexure test for imaging progressive inter- and intralaminar fracture in tape-laminate composites using X-ray computed tomography (CT). The intent of this test is to provide detailed experimental observations of ply-level damage that can be used to validate existing, and develop new, progressive damage analysis (PDA) tools. The test consists of a vertically mounted specimen which is flexed using two eccentric compressive loads using an in-situ uniaxial load stage. The flexure specimen contains a starter notch mid-span which promotes initiation of composite failure within the X-ray field of view. Specimens with two different laminate stacking sequences were tested, imaged, analyzed. For a quasi-isotropic laminate with large angle changes between adjacent plies, there was near simultaneous growth of transverse cracks and delaminations below the midplane of the laminate. For a laminate with small angles between adjacent plies, there was extensive formation of transverse crack networks which penetrated the laminate thickness without delamination growth. In addition to imaging fracture, the X-ray CT data from both specimen types were used to quantify the variability in thickness and analyze the local orientation of individual plies. Overall, the proposed test and the image-data analysis methodology provided an important insight into the fracture processes in tape laminates and highlights the inherent ply-level geometrical variabilities that should be accounted for in PDA simulations.

Buckling resistance of steel fibre-reinforced concrete encased steel composite columns

Six steel fibre reinforced high strength concrete (SFRHSC) encased steel columns were tested to investigate their structural performance without the need of conventional longitudinal steel reinforcements and stirrups. The SFRHSC encased steel composite columns were tested until failure under eccentric compression load to determine their buckling resistance including the compression and moment strength interaction behaviour. Furthermore, two composite beams with similar cross-section were subject to four-point load to obtain the load-deflection behaviour and ultimate moment resistance. The experimental results showed that, without the presence of longitudinal steel bar reinforcements, the steel fibre-reinforced composite columns exhibited ductile behaviour and showed no evidence of debonding or early cover spalling. Test evidence showed that the hooked-end steel fibres were able to bridge the growing cracks effectively. Two analytical approaches were proposed to predict the compression and moment resistances of the tested columns. The first model was based on the fibre element analysis, while the second model provided a simplified analytical prediction. Both the models were developed accounting for second-order effects in slender columns. The models were able to predict the test results with reasonable accuracy. The test results also fitted well with the predicted axial force–moment strength interaction curves.

Eccentric compression behaviour of rectangular concrete-filled steel tube columns with self-compacting lower expansion concrete

The use of a self-compacting lower expansion concrete in a concrete-filled steel tube (CFST) structure not only promotes the quality of concrete pouring but also improves the bond behaviour between the steel and the concrete. In combination with the actual stress state of the columns in the engineering structure, it is necessary to study the eccentric compression behaviour of the column. In this study, experimental studies involving both uniaxial and biaxial bending tests of rectangular self-compacting lower expansion CFST columns were carried out. The variation laws of the load–displacement curves, the lateral deflection curves and the stress–strain curves during the loading phase were analysed. Furthermore, the failure modes and the mechanical properties of the specimens under eccentric compression loads were investigated. Subsequently, the numerical models of CFST columns with self-compacting lower expansion concrete were considered and established. In order to verify the rationality of the finite element modelling, the numerical calculation results were compared with test results. Then, a parametric analysis of the compression and the bending bearing capacities of each column was carried out by changing the eccentricity of the load, and the N–M curves or N-Mx-My surfaces describing the ultimate bearing capacity of the column were obtained. Finally, by the parametric finite element analysis of the rectangular CFST columns regarding to the bearing capacity under the same eccentricity, a conclusion was obtained: when the expansion agent content γ of a specimen increased from 0% to 10%, the bearing capacity of the columns increases significantly, but when continue increasing the expansive agent content, the expansion agent content has little effect on the compression–bending bearing capacity.

Application of Eurocode 4 design provisions and development of new predictive models for eccentrically loaded CFST elliptical columns

The present study mainly aims to propose design models for the prediction of the peak strength of the concrete-filled steel tubular (CFST) elliptical columns subjected to eccentric compressive loading. At that point, the study has gain importance since the design of specifically such elliptical columns is not covered by current design codes. For example, the current provisions of Eurocode 4 provide a simplified method for the design of composite columns having circular or rectangular/square cross-sections. To this aim, first of all, the applicability and assessment of Eurocode 4 to the CFST elliptical columns under eccentric loading conditions were performed. Following, a data repository covering the experimental results of eccentrically loaded CFST elliptical columns (having different geometry, material property, load eccentricity in y and z axes, and longitudinal reinforcement ratio) was constituted. This data repository was used in the evaluation of the design guidance in Eurocode 4. Besides, the same experimental results were employed to develop two new numerical models based on gene expression programming (GEP) and artificial neural network (ANN) approaches. Finally, a sensitive statistical analysis was made to compare the prediction performances of Eurocode 4, GEP, and ANN models against experimental results. It was observed that Eurocode 4 design provisions had sufficiently accurate prediction performance, however, the developed GEP and ANN design models yielded consistent and robust prediction performance than the current design provisions by providing a much smaller mean absolute percent error of 7.5 and 1.4, respectively.

Experimental study on the effect of eccentric compressive load on the stability and load-carrying capacity of thin-walled composite profiles

This paper relates to an experimental study on the compression of thin-walled composite profiles with open cross-sectional shapes and a symmetric layup. The primary objective of the study was to determine the effect of eccentric compressive load on the stability and load-carrying capacity of the analysed profiles. The study investigated the effect of laminate layup and cross-sectional shape on the buckling load, postbuckling equilibrium path and failure load of the structures under compression. The experiments were performed on samples of short columns made of CFRP by autoclaving. Real composite structures were subjected to compression until failure; test parameters were measured in order to determine post-buckling equilibrium paths for the full range of loading conditions. The initiation of composite material damage was assessed by acoustic emission. The employed research methods made it possible to examine the problems of nonlinear stability and load-carrying capacity of the compressed structures.

Experimental and numerical study on eccentric compression performance of Dou-Gong brackets at column tops

The Dou-Gong bracket at column tops is the main force-transmitting member that connects the structural column and the roof in ancient timber buildings. The misalignment of the column or roof deviates the transmitted vertical load from the central axis of the Dou-Gong bracket, which adversely affects the vertical load-bearing performance of Dou-Gong brackets by the eccentric load. To quantitatively study the influence of the vertical eccentric load on the mechanical performance of Dou-Gong brackets at column tops, the vertical loading tests with different eccentricities were carried out on three Dou-Gong brackets. The eccentricity is defined as the ratio of the distance between the central axis of Dou-Gong brackets and the vertical load point to the side length of the top surface of Da-dou. The failure mode, vertical strength, compressive stiffness and deformability of Dou-Gong brackets at column tops under the axial compression and eccentric compression (eccentricity of 0.15 and 0.3) were obtained. The Dou-Gong bracket produces irreversible overall compressive plastic deformation under axial compressive loading. Different constitutive components of the Dou-Gong bracket squeeze significantly and compact into a whole part that is hard to separate. The final damage is the compressive collapse of Da-dou (a constitutive component of the Dou-Gong bracket) under compressive loading. However, tilting and rotation deformation of Pingban-fang and Da-dou were clearly observed under eccentric compressive loading, which results in a more brittle failure pattern. On this basis, a finite element parametric analysis on the vertical compressive performance of Dou-Gong on column tops was carried out. The results showed that a larger vertical eccentricity causes more notable tilting damage of the Dou-Gong bracket, which reduces its ultimate strength as well. When the eccentricity of vertical loading reaches 0.3, the ultimate strength of Dou-Gong brackets at column tops is reduced by 42% compared with the axial compression one.