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The purpose of this paper is to investigate the static and dynamic inelastic response of rigid and semi-rigid connections of steel structures with concrete-filled steel tube (CFST) columns built in high seismic areas, and to compare it with those with open section columns.

CFST columns are frequently used in moment resistant steel frames located in seismic areas due to their inherent advantages, including their ductility, energy absorption capacity as well as their high bearing capacity. The smart combination of steel and concrete makes it possible to benefit from the advantages of both components to the maximum. This research work presents the nonlinear dynamic response of moment resistant steel frames with CFST columns, with rigid or semi-rigid connections, built in high seismic areas, according to the Algerian seismic code RPA 99/2003, European EC8 and American FEMA 356 to show the nonlinear characteristics of this type of structures, and their advantages over steel frames with open section columns.

The paper presents the advantages of using CFST columns with rigid and semi-rigid connections on the seismic response of portal steel frames. A high performance level in terms of ductility, plastic hinges distribution and their order of appearance has been obtained. It also shows the low effect of seismic loading on the structural elements with CFST columns compared to structures with open section columns.

The investigation of the numerical results has shown the possibility of their use in the seismic areas for their adequate performance, and also with respect to the design limits specified in the seismic guidelines. In addition, this study represents a first step to develop seismic performance factors for steel structures with CFST columns in Algeria, where the Algerian code do not include a comprehensive specification for the composite steel structures.

This paper aims to obtain fire resistance of semi-rigid joints for concrete-filled steel tubular (CFST) composite frames and temperature filed distribution of composite joints in fire.

The temperature filed model of semi-rigid joints to CFST columns with slabs was made by using ABAQUS finite element (FE) software, in considering temperature heating-up stage of fire modelling. The effects of composite slab, fire type and construction location were discussed, and the model was verified by the test results. The temperature distribution of composite joint under three-side or four-side fire condition was studied by the sequentially coupled thermal analysis method. The temperature versus time curves and temperature distribution of various construction and location were analyzed.

The paper provides FE analysis and numerical simulation on temperature field of semi-rigid joints for CFST composite frames in fire. The effects of composite slab, fire type and construction location were discussed, and the model was verified by the test results. It suggests that the temperature distribution of composite joint in three- or four-side fire condition showed a different development trend.

Because of the chosen FE analysis approach, the research results may lack generalizability. Therefore, researchers are encouraged to test the proposed propositions further.

The research results will become the scientific foundation of mechanical behavior and design method of semi-rigid CFST composite frames in fire.

This paper fulfils an identified need to study the temperature field distribution of the semi-rigid joints to CFST columns and investigate the mechanical behavior of the semi-rigid CFST joints in fire.

The purpose of this study is to gain a deeper understanding of the structural behaviour of fire-exposed unbraced composite frames. Designers to date paid little attention to unbraced one-bay composite frames as structural system. There are two main reasons for this. First, codes lack simplified methods for the fire design of these frames due to their sway and the linked P-Δ effects when subjected to fire, which complicates the design. Second, it is demanding to construct external composite joints for the regarded one-bay frames. Thus, external joints in composite constructions are mostly constructed as steel joints. Nevertheless, these frames offer advantages. These include increased usable space and flexibility in the building’s use, large spans, fast construction times and inherent fire resistance.

To profit from these benefits, two different external semi-rigid composite joint were developed for the considered one-bay composite frames. The first solution based on concrete-filled steel tube columns and the second on concrete-filled double skin tube columns. Furthermore, a numerical model was established to study the fire performance of unbraced composite frames. The model was validated against four fire tests on isolated composite joints and two large-scale fire tests on unbraced composite frames.

Overall, the predictions of the numerical model were in good agreement with the test results. Thus, the numerical model is appropriate for further investigations on the fire performance of unbraced composite frames.

The sequence of construction results in significant stresses in the steel section, which creates difficulties in numerical modelling and may account for the relatively few studies carried out at room temperature. For the fire design, there was, to the best knowledge of the author, to date no numerical model available that was capable of considering the sequence of construction.

Investigate the fire performance of eccentrically loaded concrete partially encased column (PEC), using the advanced calculation method (ANSYS 18.2, 2017) and the simple calculation method in Annex G of Eurocode 4 (EN 1994-1-2, 2005). This work examines the influence of a range of parameters on fire behaviour of the composite column including: eccentricity loading, slenderness, reinforcement, fire rating and fire scenario. In this study, ISO-834 (ISO834-1, 1999) was used as fire source.

Currently, different methods of analysis used to assess the thermal behaviour of composite column exposed to fire. Analytical method named simplified calculation methods defined in European standard and numerical simulations named advanced calculation models are treated in this paper.

The load-bearing capacity of the composite column becomes very weak in the presence of the fire accident and eccentric loading, this recommends to avoid as much as possible eccentric loading during the design of construction building. The reinforcement has a slight influence on the temperature evolution; moreover, the reinforcement has a great contribution on the load capacity, especially in combined compression and bending. When only the two concrete sides are exposed to fire, the partially encased composite column presents a high load-bearing capacity value.

The use of a three-dimensional numerical model (ANSYS) allowed to describe easily the thermal behaviour of PEC columns under eccentric loading with the regard to the analytical method, which is based on three complex steps. In this study, the presence of the load eccentricity has found to have more effect on the load-bearing capacity than the slenderness of the composite column. Introducing a load eccentricity on the top of the column may have the same a reducing effect on the load-bearing capacity as the fire.

Concrete-filled steel hollow (CFHS) column is an innovation to improve the performance of concrete or steel column. It is believed to have high compressive strength, good plasticity and is excellent for seismic and fire performance as compared to hollow steel column without a filler.

Experimental and numerical investigation has been carried out to study the performance of CFHS having different concrete in-fill and shape of steel tube.

In this paper, an extensive review of experiment performed on CFHS columns at elevated temperature is presented in different types of concrete as filling material. There are three different types of concrete filling used by the researchers, such as normal concrete (NC), reinforced concrete and pozzolanic-fly ash concrete (FC). A number of studies have conducted experimental investigation on the performance of NC casted using recycled aggregate at elevated temperature. The research gap and the recommendations are also proposed. This review will provide basic information on an innovation on steel column by application of in-filled materials.

Design guideline is not considered in this paper.

Fire resistance is an important issue in the structural fire design. This can be a guideline to define the performance of the CFHS with different type of concrete filler at various exposures.

Utilization of waste fly ash reduces usage of conventional cement (ordinary Portland cement) in concrete production and enhances its performance at elevated temperature. The new innovation in CFHS columns with FC can reduce the cost of concrete production and at the same time mitigate the environmental issue caused by waste material by minimizing the disposal area.

Review on the different types of concrete filler in the CFHS column. The research gap and the recommendations are also proposed.

This paper is aimed at clarifying the behaviour of concrete-filled stainless steel tube (CFSST) slender columns. Based on the review of previous works, it can be found that the pieces of research on the behaviour of CFSST slender columns are very rare and the existing studies, to the author’s knowledge, have not covered this topic in greater depth. The purpose of this paper is to investigate the structural response and strength capacity of eccentric loaded long CFSST columns.

In this paper, a new finite element (FE) model is presented for predicting the nonlinear behaviour of CFSST slender columns under eccentric load. The FE model developed accounts for confinement influences of the concrete in-filled material. In addition, the initial local and overall geometric imperfections were introduced in the numerical model in addition to the inelastic response of stainless steel. The interaction between the stainless section and concrete in-filled was modelled using contact pair algorithm. The FE model was then verified against an experimental work presented in the literature. The ultimate strengths, axial load–lateral displacement and failure mode of CFSST slender columns predicted by the FE model were validated against corresponding experimental results.

The simulation results show that the improvement in the column strengths (compared to hollow section) is less significant when the composite columns have small width-to-thickness ratio. Finally, comparisons were made between the results obtained from FE simulation and those computed from the Eurocode 4 (EC4). It has been found that the EC4 predictions in most analysed cases are conservative for composite columns analysed under a combination of axial load and uniaxial or biaxial bending. However, the conservatism of the code is reduced with a higher slenderness ratio of the composite columns.

The simulation results throughout this research were compared with the corresponding Eurocode predictions.

This paper provides new findings about the structural behaviour of CFSST columns.

Concrete arch structures are commonly constructed for various civil engineering applications. Despite their frequent use, there is a lack of research on the response and performance of concrete arches when subjected to fire loading. Hence, this paper aims to investigate the response and in-plane failure modes of shallow circular concrete arches subjected to mechanical and fire loading.

This study is conducted through the development of a three-dimensional finite element (FE) model in ANSYS. The FE model is verified by comparison to a non-discretisation numerical model derived herein and the reduced modulus buckling theory, both used for the non-linear inelastic analysis of shallow concrete arches subjected to uniformly distributed radial loading and uniform temperature field. Both anti-symmetric and symmetric buckling modes are examined, with analysis of the former requiring geometric imperfection obtained by an eigenvalue buckling analysis.

The FE results show that anti-symmetric bifurcation buckling is the dominant failure mode in shallow concrete arches under mechanical and fire loading. Additionally, parametric studies are presented which illustrate the influence of various parameters on fire resistance time.

Fire response of concrete arches has not been reported in the open literature. The authors have previously investigated the stability of shallow concrete arches subjected to mechanical and uniform thermal loading. It was found that temperature greatly reduced the buckling loads of concrete arches. However, this study was limited to the simplifying assumptions made which include elastic material behaviour and uniform temperature loading. The present study provides a realistic insight into the fire response and stability of shallow concrete arches. The findings herein may be adopted in the fire design of shallow concrete arches.

Concrete in-filled stainless steel square tubular column combines both the benefits of concrete and steel material, providing enhanced ductility and high compressive strength to the vertical structural members. Other advantages include high stiffness, better resistance to corrosion, increased pace of construction, enhanced bearing capacity, etc. The purpose of this paper is to understand the various behavioural aspects of concrete in-filled cold-formed duplex stainless steel (CI-CFDSS) square tubular column under axial compressive loads and to assess its structural performance.

In the current paper, the performance of CI-CFDSS square tubular column is numerically investigated under uniform static loading using finite element technique. The numerical study was based on an experimental investigation, which was carried out earlier, in order to study the effects of concrete strength and shape of stainless steel tube on the strength and behaviour of CI-CFDSS square tubular column. The experimental CI-CFDSS square tubular column has a length equal to 450 mm, breadth of 150 mm, width of 150 mm, thickness of 6 mm and a constant ratio of length to overall depth equal to 3. Numerical modelling of the experimental specimen was carried out using ABAQUS software by providing appropriate material properties. Non-linear finite element analysis was performed and the load vs axial deflection curve of the numerical CI-CFDSS square tubular column obtained was validated with the results of the experiment. In order to understand the behaviour of CI-CFDSS square tubular column under axial compressive loads, a parametric study was performed by varying the grade of concrete, type of stainless steel, thickness of stainless steel tube and shape of cross section. From the results, the performance of CI-CFDSS square tubular column was comparatively studied.

When the grade of concrete was increased the deformation capacity of the CI-CFDSS square tubular column reduced but showed better load carrying capacity. The steel tube made of duplex stainless steel exhibited enhanced performance in terms of load carrying capacity and axial deformation than the other forms, i.e. austenitic and ferritic stainless steel. The most suitable cross section for the CI-CFDSS square tubular column with respect to its performance is rectangular cross section and variation of the steel tube thickness led to the change of overall dimensions of the N-CI-CFDSS-SHS1C40 square tubular column showing marginal difference in performance.

The research work presented in this manuscript is authentic and could contribute to the understanding of the behavioural aspects of CI-CFDSS square tubular column under axial compressive loads.

This study aims to further study the fire resistance of prefabricated concrete beam-column joints with end-plate connection. This paper aims to analyze the fire resistance of this joint in prefabricated reinforced concrete frame structure (PRCS).

First, the accuracy of the model is verified by using the test data. Based on this, a refined finite element model of PRCS structure with two stories and two spans is established. The influence of four working conditions with different fire floors (positions) and different axial compression ratios on the deformation, failure and fire resistance of PRCS structure are analyzed.

The results show that under the four working conditions, the fire resistance of the PRCS structure under Condition 1 and Condition 2 is smaller. It shows that the beam deformation develops slowly in PRCS structure under four kinds of fire positions, and the large displacement emerges 60 min later, which is poles apart from that of prefabricated beam column members. With the increase of the fire time, the material is damaged and deteriorated, which leads to the eccentricity of the axial load, so that the column top appears large lateral displacement. Under the Conditions 1 and 3, the lateral displacement of the column gradually decreases as the axial compression ratio rises.

It is found that there is a distinct lack of researching on the fire resistance of prefabricated joints, and the existed research studies are limited to the fire resistance of members. Thus, it is necessary to strengthen the first floor and side column design of prefabricated frame structure.

Measuring texture parameters are time consuming and expensive; it is necessary to develop an efficient and rapid method to evaluate them. Image analysis can be a useful tool. The purpose of this paper is to predict texture parameters in different beef cuts applying image analysis techniques.

Samples were analyzed by scanning electron microscopy. Texture parameters were analyzed by instrumental, image analysis techniques and by Warner–Bratzler shear force.

Significant differences (p<0.05) were obtained for image and instrumental texture features. Higher amount of porous were observed in freeze dried samples of beef cuts from Gluteus Medius and semintendinosus muscles. A linear trend with a linear correlation was applied for instrumental and image texture. High correlations were found between image and instrumental texture features. Instrumental parameters showed a positive correlation with image texture feature.

This research suggests that the addition of image texture features improves the accuracy to predict texture parameter. The prediction of quality parameters can be performed easily with a computer by recognizing attributes within an image.