Investigation of the Structural Behaviour of RC Beam-Column Sub-frame Subjected to Progressive Collapse

Feiliang Wang,Sandeep Shah,Xiaoping Wang,Xing-Er Wang,Wang-Xi Zhang,Bo Pang,Jian Yang 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.4

The aim of this study is to investigate the effects of varying design variables on the structural behaviour of reinforced concrete (RC) sub-frames under progressive collapse. A finite element modelling approach is presented and validated against the experimental results concerning a 2D frame (3 columns and 2 beams) and a 3D frame (4 columns and 3 beams). The performance of the RC sub-frame is discussed by choosing the scenarios of the exterior, interior, and multiple column loss, respectively, and by increasing the number of stories and bays. Further studies are conducted based on the numerical method to reveal the effect of beam longitudinal reinforcement ratio (BLRR), beam section depth (BSD), and concrete compression strength (CCS). The results show that both BLRR, CCS and BSD have a significant influence on the compressive arch action (CAA) capacity of the structure under progressive collapse, and the load-carrying capacity of the RC sub-frame increases with an increasing number of stories.

Pseudo-plastic Collapse Performance of Multi-span Continuous Beams with CFS Sigma Sections: A Numerical Study

Feiliang Wang,Jian Yang,James B. P. Lim 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.2

Conventional design approaches for cold-formed steel (CFS) members were mainly based on elastic theory, including the effective width method and the direct strength method, where the influence of moment redistribution on the failure load was neglected. A Pseudo-Plastic Design Method (PPDM) has been presented for analysing multi-span CFS structures in order to enhance the economical of resistance prediction. This method is analogical to conventional plastic design theory as it introduces a pseudo-plastic moment resistance to accommodate the benefit of the redistribution of moments. In the present study, finite element modelling approach was introduced based on ANSYS package, and comparisons were made between numerical and PPDM results, in particular, on load-carrying capacity, pseudo-plastic hinges formation, moment redistribution and failure behaviour. Extensive sensitivity studies have been carried out in validation of PPDM application for full-scale continuous beams under various span number, span length, steel yield strength and cross section properties. The study shows that the design employing PPDM can lead to a better economic benefit than the aforementioned methods for CFS sigma continuous beams.

Numerical Studies of the Rotational Stiff ness of Purlin–Sheeting System

Feiliang Wang,Hanwen Zhang,Jian Yang,Li Bai,Chong Ren 한국강구조학회 2018 International Journal of Steel Structures Vol.18 No.3

In light-gauged steel purlin-to-sheeting roof systems, the attached sheeting can provide rotational restraints to the purlin. The magnitude of the additional rotational stiff ness off ered by the sheeting will aff ect the load bearing capacity of the purlin. The current design method in Eurocode3 (EC3) is less accurate in predicting the purlin–sheeting rotational stiff ness as it neglects the eff ect of wall thickness of the purlin. An integral model is introduced based on the fi nite element method. Comparisons are made between numerical results and existing experiments and a good agreement is observed. Parametric studies are conducted based on the validated model to investigate the infl uences of geometric dimensions on the rotational stiff ness. Two modifi ed coeffi cients are proposed for calculating the rotational stiff ness based on the codifi ed formulae in EC3, where the eff ect of the wall thickness and the fl ange width of the purlin are both considered.

Effect of Horizontal Restraints on Progressive Collapse Resistance of Precast Concrete Beam-Column Framed Substructures

Feiliang Wang,Jian Yang,Sandeep Shah 대한토목학회 2020 KSCE Journal of Civil Engineering Vol.24 No.3

The aim of this study is to reveal the effect of horizontal restraints on the progressive collapse behaviour of precast concrete (PC) framed substructures. To this end, two one-thirds-scale 2-storey 2-span beam-column sub-frames with varying horizontal restraint conditions have been experimentally investigated. A nonlinear finite element (FE) model based on ABAQUS package was established and validated against failure modes and load-carrying capacity recorded in the test. Parametric studies were conducted using the FE simulation approach to investigate the effect of key design variables on the performance of the PC sub-frames. It was found that the failure of the PC beam-column assemblies was dominated by pull-out of anchorage bars on side joints and the load-carrying capacity of the PC sub-frames wereconsiderably affected by horizontal restraints.

A comparison of structural performance enhancement of horizontally and vertically stiffened tubular steel wind turbine towers

Yu Hu,Jian Yang,Charalambos C. Baniotopoulos,Feiliang Wang 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.73 No.5

Stiffeners can be utilised to enhance the strength of thin-walled wind turbine towers in engineering practise, thus, structural performance of wind turbine towers by means of different stiffening schemes should be compared to explore the optimal structural enhancement method. In this paper two alternative stiffening methods, employing horizontal or vertical stiffeners, for steel tubular wind turbine towers have been studied. In particular, two groups of three wind turbine towers of 50m, 150m and 250m in height, stiffened by horizontal rings and vertical strips respectively, were analysed by using FEM software of ABAQUS. For each height level tower, the mass of the stiffening rings is equal to that of vertical stiffeners each other. The maximum von Mises stresses and horizontal sways of these towers with vertical stiffeners is compared with the corresponding ring-stiffened towers. A linear buckling analysis is conducted to study the buckling modes and critical buckling loads of the three height levels of tower. The buckling modes and eigenvalues of the 50m, 150m and 250m vertically stiffened towers were also compared with those of the horizontally stiffened towers. The numbers and central angles of the vertical stiffeners are considered as design variables to study the effect of vertical stiffeners on the structural performance of wind turbine towers. Following an extensive parametric study, these strengthening techniques were compared with each other and it is obtained that the use of vertical stiffeners is a more efficient approach to enhance the stability and strength of intermediate and high towers than the use of horizontal rings.

Prediction of Catenary Action Capacity of RC Beam-Column Substructures under a Missing Column Scenario Using Evolutionary Algorithm

Iftikhar Azim,Jian Yang,Muhammad Farjad Iqbal,Zafar Mahmood,Muhammad Faisal Javed,Feiliang Wang,Qing-feng Liu 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.3

Catenary action plays crucial role in resisting the applied vertical load at large deformations stage in reinforced concrete (RC) structures. This paper aims to predict the catenary action capacity of RC beam-column substructures by utilizing the distinctive properties of gene expression programming (GEP). The input parameters selected for the modelling are: double-beam span-to-depth ratio, relative axial restraints stiffness, relative rotational restraints stiffness, bottom and top longitudinal reinforcement ratios, and yield strength of longitudinal rebars. A comprehensive and reliable database was collated from internationally published research articles to develop and verify the model. The GEP-based model was assessed by comparing its performance with regression based model. Various statistical indicators and external validation criteria suggested in literature proved that the model is accurate and possess high prediction and generalization capacity. Sensitivity analysis was carried out to show the contributions of the input parameters, while parametric analysis was performed to show that the proposed model is not merely a combination of the input parameters but can accurately represent the given physical system. The proposed formulation from GEP is found to be simple, robust, and easy to utilize for pre-design purposes.