Double Skin Composite Wall Research Articles

Research on the axial compressive behavior of double skin composite wall with steel truss

This paper presents a research on the axial compressive behavior of double skin composite wall(DSCW) with steel truss, which is a novel type of composite wall. The steel truss is constructed by two angles and kinked rebar is acting as the interface connector. Experimental study was introduced briefly and software ABAQUS was adopted for numerical simulation analysis. By comparing with the experimental results, the accuracy of the finite element model was verified and then structural behavior of the walls was comprehensively evaluated. A parametric study was carried out to investigate the influences of the strength of steel plate and infilled concrete, truss horizontal spacing to thickness ratio on the compression responses of the composite wall. The results show that the better ductility of the composite wall can be achieved by the lower concrete strength and higher steel plate strength. Besides, the strength of the concrete and the steel plate tends to have a linear correlation with the load-carrying capacity. The horizontal spacing to thickness ratio has the significant influence on the failure mode of the composite wall and local buckling of steel plate can be avoided when the ratio is less than a certain value. In addition, the calculation formula for the axial compressive load-carrying capacity of the composite wall was proposed to provide a reference basis for the application of this type of composite walls in practice.

Seismic damage assessment for flexural double skin composite walls based on the modified Park-Ang model

The damage indices are widely used to evaluate the performance level and damage state of structural elements in buildings subjected to seismic actions. Despite the widespread promotion of double-skin composite walls (DSCWs) in global construction practices, the research related to the seismic damage assessment of DSCW members is still limited. In order to establish a seismic damage assessment procedure for DSCW members, an experimental database that includes 37 test results of DSCW specimens subjected to cyclic loads was built in this paper. Based on an existing modified Park-Ang model, an empirical expression of the combination coefficient is introduced. The damage state levels of DSCWs are determined as follows: Basically intact (DS0), Slight damage (DS1), Mild damage (DS2), Moderate damage (DS3), Relatively severe damage (DS4), Severe damage (DS5), and Critical collapse (DS6). The typical damage characteristics and repair methods are introduced and discussed. Subsequently, a comprehensive statistical analysis is conducted to study the probabilistic correlation between these damage states and the corresponding index specific to DSCW members. Fragility functions for each damage state associated with the damage index have been developed. The threshold values of the damage index corresponding to the damage states are also provided. This paper intends to provide a theoretical foundation for performance-based seismic design and post-earthquake damage assessment of DSCW structures.

Eccentric compressive behavior of PBL-stiffened double-skin composite walls in bridge pylons

Double-skin composite walls (DSCWs) stiffened with perfobond ribs (PBLs) have gained popularity for use in large-scale structures. This investigation aims to provide valuable insights into the performance of PBL-stiffened DSCWs when subjected to eccentric compressive loads. An experimental investigation was conducted on eight PBL-stiffened DSCWs. The failure modes, local buckling behavior, load-deflection behavior, moment–curvature relationship, and strain distribution were analyzed. The results indicate that an increase in the interval of longitudinal PBLs on the compressive zone of the DSCW specimens leads to a reduction in eccentric compressive resistance due to premature local buckling. However, the transverse PBL interval and removal of transverse rebars had negligible effects on the local buckling behavior of the faceplates and did not affect the resistance of the specimens. The ductility index of DSCWs slightly increased with an increase in concrete strength and was further enhanced by the presence of headed studs. The introduction of studs on the faceplates effectively delayed the onset of local buckling and improved the resistance of the DSCWs under eccentric loads. Throughout the loading process, the longitudinal strain remained almost linear, and the neutral axes remained unchanged, indicating that the plane section assumption works for PBL-stiffened DSCWs. To develop N–M interaction curves of PBL-stiffened DSCWs under eccentric loads, the effective area method was introduced to predict the post-buckling strength of unilaterally restrained PBL-stiffened plates. The proposed curves provided accurate and relatively conservative predictions of the experimental results due to the reasonable consideration of the local buckling effect.

Axial compressive behavior of PBL-stiffened double-skin composite walls considering local buckling: Experimental and theoretical investigation

Double-skin composite walls (DSCWs) stiffened with perforated ribs (perfobond leiste in German, abbreviated as PBL) has gained popularity in large-scale structures due to their industrial construction potential. This study aims to explore the axial compressive behavior of PBL-stiffened DSCWs, considering the post-local buckling effect of the faceplates. Six PBL-stiffened DSCWs underwent an experimental investigation under axial compressive loads to evaluate their failure mode, load-axial behavior, ductility, and local buckling behavior. The study also examined the effect of the spacing of transverse and longitudinal PBLs and the introduction of headed studs on the axial compressive behavior of DSCWs. Results reveal that decreasing the spacing of transverse PBLs enhances the confining effect on the infilled concrete, increasing the axial compressive resistance of DSCWs. The introduction of studs delays local buckling and results in strain-hardening of the faceplates, improving the axial compressive resistance of DSCWs. However, increasing the longitudinal PBL spacing weakens the out-of-plane restraint of the faceplates, decreasing both local buckling load and compressive resistance. Assuming the longitudinal PBLs as out-of-plane continuous elastic supports, the elastic critical local buckling coefficient of PBL-stiffened plates with unilateral restraints was derived using the Ritz method. Based on this, the critical relative stiffness of the PBL can be determined, which helps in identifying the local buckling mode of the PBL-stiffened plates. To estimate the post-local buckling behavior of PBL-stiffened plates with unilateral restraints, an effective area method was proposed. Finally, a formula was proposed to predict the axial compressive resistance of PBL-stiffened DSCWs, considering the post-buckling effect. A suggested design procedure for PBL-stiffened DSCWs was also provided.

Nonlinear modeling methods for cyclic analysis of double-skin composite shear walls

The double-skin composite walls (DSCWs) are attractive as the main seismic element in structures. The interaction between concrete and steel provides DSCWs with superior seismic and structural performance. An urgent need is to develop accurate and reliable numerical modeling methods to analyze the mechanical mechanisms of DSCWs and predict their responses in structures. This paper provided both continuum finite element (CFE) modeling and fiber-based modeling methods for the nonlinear cyclic analyses of DSCWs. The common problems of numerical simulations in existing studies were summarized and discussed. An alternative CFE modeling method using the ABAQUS program was proposed through explicitly modeled concrete discrete cracks and CVGM (cyclic void growth model)-based steel fracture criterion. The passive confinement of concrete and the geometric local buckling of steel faceplate were taken into account. As for the system-level analyses, a fiber-based modeling method was developed. The concrete confining effect, as well as the local buckling and ductile fracture of steel fibers, were considered and driven by the physically reliable uniaxial constitutive models. Both the CFE models and fiber-based models were validated by experimental results, and a good agreement was achieved. Two modification methods for the enhancement of confining effect due to the interactional constraints of concrete in continuous multi-cavities were proposed. Furthermore, the internal force responses of steel sheets were extracted by CFE simulation results and compared with the steel fibers of the fiber-based model, to verify the reliability of the RSMM (reinforcing steel material model) parameters that control the buckling and fracture of the steel fibers.

Seismic performance study on a precast double-skin composite wall with circular CFSTs

A novel precast double-skin composite wall with circular concrete-filled steel tubes (DSCW-C) is proposed in this paper. The new structure comprehensively considers the advantages of the double-skin composite wall and the circular concrete-filled steel tubes (CFST). Two circular boundary CFST and two middle steel plates are welded together as the embedded steel components of DSCW-C. Four 1/2-scale specimens with 2 shear-span ratios and 2 connection methods were fabricated and subjected to cyclic loadings to investigate their seismic performance. The failure modes, strength capacity, deformability, and energy dissipation of the specimens were meticulously explored. The experimental results show favourable structural behaviours of the structures, especially in the specimens with full-section welding of the steel tubes. A bending-based strength capacity prediction method was then established correspondingly and showed sufficient accuracy with the DSCW-C specimens.

Behavior and design method of double skin composite wall under axial compression

This paper presents an experimental and analytical study on the behavior of DSCW loaded in axial compression. Two full-scale tests of DSCW were conducted under the axial compressive load. The effect of the height of DSCW was taken into consideration. Moreover, the failure mode, axial load versus displacement relationship, displacement ductility, and strain response of DSCW were studied comprehensively. The results showed that all DSCW specimens underwent a similar damage process and exhibited the global buckling failure mode. DSCW can provide high axial load-carrying capacity and satisfied displacement ductility. The nonlinear FE model, which could capture the material and geometric nonlinearity of DSCW was proposed and validated against test results. Parametric analysis was conducted to study the influence of various parameters (yield strength of steel, thickness of steel plate, width-to-thickness ratio, and compressive strength of infilled concrete.) on the axial behavior of DSCW. The formulae for calculating the cross-sectional axial load-carrying capacity of DSCW were proposed. The predicted results agreed well with the FEA results. The theoretical formulae for predicting the axial load-carrying capacity of DSCW were present and validated by the test results. The proposed design method could provide a reliable reference for designing DSCW under axial load.

Cyclic behavior and mechanical model of a novel endplate connection to double-skin composite wall with slip-critical blind bolts

This paper presents an assembled bolted endplate joint for connecting steel beams and double-skin composite walls (DSCWs). The slip-critical blind bolts (SCBBs) were utilized in this novel joint to decrease welding work on-site. In order to investigate the seismic performance of this novel joint, two full-scale beam-to-wall SCBB endplate connection specimens with different design parameters were tested under incremental cyclic loading. Two failure modes of the specimens, namely beam bucking (mode I) and column wall damage (mode II), were finally observed. Analyses of test results indicated that a properly designed SCBB endplate connection with failure mode I could exhibit stable load-bearing capacity and satisfactory energy dissipating capacity. On the contrary, failure mode II should be avoided in engineering due to its unacceptable performance. Finite element models (FEMs) were developed and validated subsequently to further investigate the interior stress and damage distribution. The parametric analysis was also conducted using the FEMs. Based on the experimental results and numerical analyses, an alternative mechanical model was proposed to predict the bending resistance capacity of the column wall. The segmentation method was adopted in the model to eliminate the dependency on a specific pattern of yield line without reducing the accuracy. The reliability of the strength-prediction model of the column wall was validated through the results of the parametric analysis. The design methods and specifications for the components of the joint were finally summarized to make the SCBB endplate connection effectively used in practical applications.

Seismic behavior of low shear-span ratio double-skin composite wall with L-shaped connectors

A double-skin composite wall (DSCW) with innovative L-shaped connectors was proposed, which can be simply constructed and quickly assembled to promote the development of a prefabricated steel structure. To further examine the seismic capacity of the novel DSCW, five DSCWs were designed and fabricated, each with a low shear-span ratio. The testing parameters include the welding spacing, distance between connectors, and the width-to-thickness ratio of the wall-to-steel faceplate. The failure mode of each DSCW specimen was observed, while determining the load-carrying capacity, the hysteretic curve, the skeleton curve, and the displacement ductility coefficient. Moreover, the distribution and development of the boundary column strains, steel faceplate strains, and L-shaped connector strains were researched. The test results showed that the DSCWs with a low shear-span ratio had excellent load-carrying capacity and ductility, and all specimens experienced flexural-shear failure. Decreasing the welding spacing of L-shaped connectors or reducing the distance between L-shaped connectors can enhance the capacity of energy dissipation and ductility, but such a distance reduction has a slight effect on the shear strength. When the thickness of the steel faceplate on different specimens is the same, the load-carrying capacity of the DSCW specimen obviously improves as the width-to-thickness ratio of the wall-to-steel faceplate increases. Finally, shear strength calculation formulas of the novel DSCW under the low shear-span ratio were established.

Compressive behavior of double-skin composite walls considering local buckling and post-buckling effect

This paper presents axial compressive experiments of double-skin composite walls (DSCWs) with novel dumbbell-shaped connectors (DSCs) and traditional headed studs. The effects of the wall thickness, material strength, and diameter and number of the headed studs on the axial behavior of the DSCWs were analyzed. The failure modes of the specimens included the local buckling of the steel plates and compressive crushing of the concrete. The buckling position was between two adjacent rows of connectors. The experimental results demonstrated that the denser the arrangement of the connectors and the larger the diameter of the headed studs, the higher the critical buckling stress and axial bearing capacity of the specimens. The compressive stress–strain relationship of the steel material was determined considering the buckling and post-buckling behaviors of steel plates. According to the superposition principle, the theoretical load–displacement relationships of the five specimens were calculated, and the theoretical curves were in good agreement with the experimental results. The calculation formula for the axial bearing capacity of the specimens was introduced with some simplified assumptions, and the average value of the experiment/calculation ratio was 96.14%. ABAQUS software was used to simulate the DSCW specimens, and the failure modes of the models were in good agreement with the experiments. The average value of the experiment/simulation ratio for the peak load was 98.77%. Based on the verified benchmark model, the effects of four parameters on the compressive behavior of DSCWs were analyzed.

Performance Evaluation of Composite Wall with Boundary Column Having Triangular Corrugation

Abstract: Composite wall is an innovation in the field of Civil Engineering that enhances the constructability by eliminating reinforcing bars and formwork. Double skin composite wall consist of a concrete core is placed between outer steel plates. By providing corrugation in the steel plate improves the seismic behavior and also stability against buckling. This paper aims to the performance evaluation of corrugation on composite wall with boundary column. For this study, four FE models of composite wall with boundary column having triangular corrugation were analyzed using Ansys 2022 R1. Composite wall with different height of corrugation ie., 25 mm, 30 mm, 40 mm and 45 mm is evaluated under monotonic loading to understand the total deformation and equivalent stress. Also perform buckling analysis on the better model obtained from different geometry of corrugation. Study shows that model with 45 mm height of corrugation shows maximum load carrying capacity

Seismic performance of double skin composite wall under maximum considered far-field earthquake loading protocol

In order to evaluate the realistic seismic performance of double skin composite wall (DSCW) under earthquakes, 4 full-scale experiments of DSCW were conducted using the maximum considered far-field earthquake loading protocol. The methodology for developing the loading protocol was described, and all necessary assumptions and decisions of the development were briefly introduced. The effect of boundary columns thickness and axial compression ratio of DSCW were taken into consideration. The experimental results showed that all DSCW specimens underwent a similar damage process and exhibited the flexural failure mode. The DSCW component has desirable ductility under the maximum considered earthquakes. Improving the thickness of boundary columns increases the peak strength and ultimate strength of DSCW but significantly decreases the displacement ductility. Increasing the axial compression ratio enhances the peak strength and initial stiffness of DSCW but reduces the displacement ductility of DSCW significantly. The thickness of boundary column has a negligible impact on the energy dissipation capacity of DSCW. However, the DSCW with the thicker thickness of boundary columns gains less energy dissipation cycles due to its lower displacement ductility. Increasing the axial compression ratio improves the energy dissipation capacity of DSCW but reduces the energy dissipation cycles.

Development of loading protocols for experimental testing of double skin composite wall

Double skin composite wall (DSCW) is an innovative composite shear wall taking the advantage of concrete and steel components, which has gained popularity among high-rise steel buildings worldwide. Quasi-static testing is used widely for evaluating the seismic behavior of DSCW components. The selection of appropriate loading protocols is critical for obtaining an accurate assessment of seismic performance. There is a need that the loading protocols subjected to a specimen are supposed to reasonably reflect its realistic seismic demands under earthquakes. In this paper, the loading protocols which could represent the seismic demand of DSCW members under real earthquake excitations (far-field and near-fault earthquakes) are proposed. The refined numerical simulation model of DSCW, which could capture the nonlinear behavior of DSCW under hysteretic loads, is presented. The methodology for developing loading protocols is introduced in detail, and all necessary assumptions and decisions of the development are discussed. The results show that the near-fault earthquakes tend to impose high deformation demands on DSCW structures than far-field ground motions. The damage of the DSCW structure is mainly caused by cumulative deformations under far-field earthquakes, while a few large excursions would induce the damage under near-fault earthquakes. The CDFs of proposed loading protocols have a considerable agreement with the analysis results, which indicated that the loading protocols enable an accurate assessment of DSCW components.

Buckling behavior of double skin composite walls under axial compressive load

In this paper, the steel faceplate buckling of double skin composite walls stiffened with studs or steel-bar trusses is studied and analyzed by the axial compressive test, including ten specimens. According to the investigation, the buckling mode of steel faceplate, whose restraint situation is four points arranged in different shapes, is observed, and the calculated equation of buckling stress is proposed. Based on the test, the buckling strain monitored by strain gauges and maximum strength increases with the decline in welding spot spacing-to-thickness ratio and spacing aspect ratio. According to the finite element model (FEM) established by ABAQUS, the failure mode of the walls is simulated well. The buckling stress and load–displacement curve obtained by FEM corresponds well with these of the test. The parametric analysis is conducted to study the influence of initial geometric imperfection by considering the welding spot spacing-to-thickness ratio and spacing aspect ratio on faceplate buckling stress. When the initial geometric imperfection is larger than 1/1000 of the vertical welding spot spacing, the faceplate buckling stress drops more slowly with the increase of initial geometric imperfection. The relationship between the buckling stress and welding spot spacing-to-thickness ratio obeys the Euler curve. The buckling stress of the steel faceplate decreases linearly with the increase in the spacing aspect ratio. The results by using the buckling equations with the consideration of the initial geometric imperfection and spacing aspect ratio are approximately in accordance with the simulated results.

Seismic behavior of corrugated double-skin composite wall (DSCW) with concrete-filled steel tubes: Experimental investigation

This paper presents the seismic behavior of corrugated double-skin composite wall (DSCW) with concrete-filled steel tube boundary elements. Fifteen 1/3-scale DSCW specimens, varying in shear span ratio, axial compression ratio, corrugation direction and shape, connector type and steel faceplate profile, were tested under cyclic loading. All specimens except W15 failed in flexural failure. The cyclic response of vertical corrugated DSCW was much better than that of horizontal corrugated DSCW. Compared to flat DSCW, corrugated DSCW, even with a 20% reduction in the concrete cross-sectional area, had considerably higher peak load, ductility ratio and energy dissipation. The setting of connectors slowed down the damage rate of the corrugated DSCW in the failure stage, and also significantly improved the peak load and ductility of the corrugated DSCW with λ = 1.5. Increasing the shear span ratio significantly reduced the peak load and initial stiffness of the DSCW, but did not affect the ductility and energy dissipation. The corrugated DSCW, failed in flexural-dominated mode, had excellent collapse resistance, achieving a drift ratio exceeding 2% and a ductility ratio greater than 3.3, and it was recommended to take n = 0.3 as the limit value of axial compression ratio of corrugated DSCW. Moreover, the average ratio of Pt/Pc was 1.082 with a mean absolute error of 0.068 and a root mean square error of 0.084, indicating that the calculated value of proposed formulas for calculating the lateral strength of vertical corrugated DSCW can reflect the measured data well.

BEHAVIOR OF DOUBLE SKIN FLAT COMPOSITE WALL UNDER LATERAL LOAD

Shear walls are the primary lateral load-carrying elements in tall buildings. The composite shear walls with double steel plates and filled concrete are composed of two steel plates with studs inside, they were developed to enlarge the building space, and to delay the appearance of cracks by using the steel plates as formwork. Double skin composite wall panels can offer high strength and robustness while improving the convenience of construction, with great potential for application in nuclear power plants

In-plane cyclic tests of double-skin composite walls with concrete-filled steel tube boundary elements

This paper focused on a new type of double-skin composite wall in which concrete-filled steel tubes are used as boundary elements, and steel-bar space trusses are used to stabilize the faceplates. The new composite wall is architecturally attractive and has some perceived advantages in strength and construction. However, limited knowledge exists regarding its behavior under the combined cyclic in-plane lateral load and axial compression. This paper reports the test results of five experimental specimens subjected to the intended combined loading. Among the tested specimens, four developed the preferred flexure-dominated limit state, while one developed the undesired shear-dominated limit state. The specimens with the flexure-dominated limit states exhibited ductile behavior up to the drift of 0.036 rad with minor strength degradations. It was found that local buckles in the faceplates of the composite wall did not compromise wall lateral resistance. The effect of using supplementary steel headed studs to stabilize faceplates is also addressed in the paper. Aside from the experimental work, a simplified model was established to compute the wall plastic moment and lateral resistance of the wall with the flexure-dominated limit state. Predictions from the model were found to agree well with the test results, suggesting the model can be used for future design and analysis of the composite wall.

Experimental study and numerical simulation on seismic behavior of double-skin composite wall

An innovative double-skin composite wall (DSCW) with L-shaped connectors which can be quickly assembled and simply constructed was proposed. Taking the boundary column length and shear span ratio of the wall as parameters, the failure mode and seismic behavior of the composite shear wall were studied through quasi-static tests of four specimens. Based on the open-source software, OpenSees, the fiber model of the DSCW with L-shaped connectors was established, and the parametric study applied for the fiber model. The common failure phenomenon of each specimen lied in the steel plate tearing at the bottom of the end column, the concrete crushing at the tearing place, and local bulging at the bottom of the steel plate. Test results showed this type of composite shear wall had excellent bearing capacity and ductility, and the peak load range is 734.2 kN–991.3 kN, and the ductility coefficient is between 3.07 and 4.70. According to the analysis of the test results, the deformation performance and bearing capacity of the specimen were affected by both the length and the length -thickness ratio of the boundary column; the change in the shear-span ratio significantly affected the stiffness of the specimen in the elastic stage. With the comparison of the simulation results and the test data, the difference between the peak loads is less than 6%, which verifies the correctness of the model. Thus, taking the specimen model as the benchmark model, the parameters of the model were analyzed, as the supplementary verification of test results.

Experimental study on the hysteresis behavior of L-shaped double-skin composite wall with concrete-filled steel tubes

In this paper, the seismic behavior of L-shaped double-skin composite wall (DSCW) with concrete-filled steel tubes were investigated. The influence of different parameters, i.e., axial compression ratio, shear span-to-depth ratio, corrugation size, corrugated arrangement, flange size and CFST side column were discussed based on cyclic tests. The hysteresis behavior of DSCW specimens in terms of hysteresis curves, skeleton curves and rigidity deterioration were analyzed. The failure mechanism, as well as the composite effect between each component was also compared based on the strain analysis. It was concluded that the L-shaped DSCW has favorable seismic ductility and toughness with the maximum lateral drift angle of 3%. With the increase of axial compression ratio, the peak load of DSCW specimens increased while the post-peak ductility decreased. By contrast, the peak load of DSCW specimens decreased with the increase of shear span-to-depth ratio. More corrugations are effective to increase the seismic behavior of L-shaped DSCW and it was recommended that the corrugations should be arranged vertically. The flange size has limited influence on the failure processes and carrying capacity of DSCW specimens, while the stress distribution was highly dependent on the flange design of DSCW. The application of concrete-filled steel tubes (CFST) side column is effective to increase the seismic behavior of DSCW and also has significant influence on the composite effect between each component.

Experimental seismic behavior of T-shaped double skin composite wall with steel truss

The double skin composite wall (DSCW) with steel truss is an innovative lateral load resisting member which composed of two steel plates, core concrete, concrete-filled steel tubes (CFSTs) as boundary members, and steel truss connectors. The effects of the aspect ratio and the flange wall width on the seismic performance are investigated based on the quasi-static test of full-scale T-shaped DSCWs with steel truss. The failure mode, load-displacement response, shear strength, ductility, energy dissipation, shear deformation, and stress distribution of the specimens were analyzed. The test results showed that the failure mode of the T-shaped DSCW with steel truss specimens with aspect ratios of 2.0 and 2.5 was flexure-shear failure, which was characterized by shear buckling of the steel plate, local buckling, and fracture of the boundary members, and of crushing of core concrete. The T-shaped specimens with a small aspect ratio have a higher shear strength, ductility, energy dissipation capacity, and shear deformation proportion. The T-shaped specimen with a long flange wall also has a higher shear strength, but the ductility, energy dissipation capacity, and shear deformation proportion are small. The stress distribution indicates that the T-shaped specimen is more likely to failure due to the insufficient flexural strength of the boundary member. The theoretical formula for the flexural strength of T-shaped DSCW with steel truss is established, and the validation results show that the formula is accurate and safe.