Wind-Moment Design of Semi-Rigid Un-braced Steel Frames using Cruciform Column (CCUB) Section

Shek Poi Ngian,Mahmood Md Tahir,Arizu Sulaiman,Tan Cher Siang 한국강구조학회 2015 International Journal of Steel Structures Vol.15 No.1

The design of un-braced frames using wind-moment method (WMM) with cruciform column (CCUB) section as verticalmember is presented here. Steel frames on a regular grid with approximately equal column spacings in the y-y and z-z directionusing UC/UB sections has resulted in minor axis controlled the design, which leads to a significant loss in performance. Theuse of CCUB sections with equal Iy and Iz warrants an equal behaviour in both directions whilst ensuring that both the majorand minor axis beam to column connections remain straightforward. The study has been conducted on 2-bay and 4-bay planeframes with 2, 4, 6 and 8 storey heights, and two different load cases are considered: minimum wind load in conjunction withmaximum gravity load and vice versa. Structural design optimization of steel frames was conducted on the selection of steelsections for beam and column. The selection was carried out in such a way that the steel frame had the minimum weight whilethe performance of the structure was within the limitations described by BS EN 1993-1-1: 2005. Significant column weightsavings (between 17-66%) was achieved by using CCUB section in the design, as compared to conventional UC sections.

Limiting the sway on multi-storey un-braced steel frames bending on weak axis with partial strength connections

Mahmood Md. Tahir,Shek Poi Ngian 국제구조공학회 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.38 No.6

This paper investigates the design using wind-moment method for semi-rigid un-braced steel frames bending on weak axis. A limiting sway method has been proposed to reduce the frame sway. Allowance for steel section optimization between moment of inertia on minor axis column and major axis beam was used in conjunction with slope-deflection analysis to derive equations for optimum design in the proposed method. A series of un-braced steel frames comprised of two, four, and six bays ranging in height of two and four storey were studied on minor axis framing. The frames were designed for minimum gravity load in conjunction with maximum wind load and vice-versa. The accuracy of the design equation was found to be in good agreement with linear elastic computer analysis up to second order analysis. The study concluded that the adoption of wind-moment method and the proposed limiting sway method for semi-rigid steel frame bending on weak axis should be restricted to low-rise frames not more than four storey.

Limiting the sway on multi-storey un-braced steel frames bending on weak axis with partial strength connections

Tahir, Mahmood Md.,Ngian, Poi Shek Techno-Press 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.38 No.6

This paper investigates the design using wind-moment method for semi-rigid un-braced steel frames bending on weak axis. A limiting sway method has been proposed to reduce the frame sway. Allowance for steel section optimization between moment of inertia on minor axis column and major axis beam was used in conjunction with slope-deflection analysis to derive equations for optimum design in the proposed method. A series of un-braced steel frames comprised of two, four, and six bays ranging in height of two and four storey were studied on minor axis framing. The frames were designed for minimum gravity load in conjunction with maximum wind load and vice-versa. The accuracy of the design equation was found to be in good agreement with linear elastic computer analysis up to second order analysis. The study concluded that the adoption of wind-moment method and the proposed limiting sway method for semi-rigid steel frame bending on weak axis should be restricted to low-rise frames not more than four storey.

Finite Element Analysis of Flush End-plate Connections Connected to Column Web

Mahmood Md Tahir,Irwan Juki,Lee Hong Yong,Shahrin Mohammad,Shek Poi Ngian 한국강구조학회 2011 International Journal of Steel Structures Vol.11 No.3

Eurocode 3: Part 1.8 (2005b) does not cover the empirical design for flush end-plate connections connected to column web. Thus, experimental works need to be performed to investigate the behaviour of the minor axis end-plate bolted connection. However, the experimental tests are expensive, tedious and time consuming to be conducted. Alternatively, finite element modelling and analysis can be adopted to predict the behaviour of the connection accurately. Five specimens of flush end-plate connections connected to column web with variable parameters have been tested and the results are compared with finite element analysis. Finite element models with enhanced strain solid and contact joint elements are used to stimulate the connection behaviour. The objective of this paper is to compare and validate the accuracy and reliability of the finite element model by correlating moment rotation (M-Φ) curves between the finite element model and experimental tests. The comparison shows a reasonable agreement between the predicted results from FEA and the experimental tests.

Application of waste tire rubber aggregate in porous concrete

Mahdi Shariati,Arian Heyrati,Yousef Zandi,Hossein Laka,Ali Toghroli,Peiman Kianmehr,Maryam Safa,Musab N.A. Salih,Shek Poi-Ngian 국제구조공학회 2019 Smart Structures and Systems, An International Jou Vol.24 No.4

This study aimed to categorize pervious rubberized concrete into fresh and hardened concrete analyzing its durability, permeability and strength. During the globalization of modern life, growing population and industry rate have signified a sustainable approach to all aspects of modern life. In recent years, pervious concrete (porous concrete) has significantly substituted for pavements due to its mechanical and environmental properties. On the other hand, scrap rubber tire has been also contributed with several disposal challenges. Considering the huge amount of annually tire wastes tossing out, the conditions become worse. Pervious concrete (PC) gap has graded surface assisted with storm water management, recharging groundwater sources and alleviate water run-offs. The results have shown that the use of waste tires as aggregate built into pervious concrete has tremendously reduced the scrap tire wastes enhancing environmental compliance.

The effect of wollastonite powder with pozzolan micro silica in conventional concrete containing recycled aggregate

Du Dinh-Cong,Mohammad. H. Keykhosravi,Rayed Alyousef,Musab N.A. Salih,Hoang Nguyen,Hisham Alabduljabbar,Abdulaziz Alaskar,Fahed Alrshoudi,Shek Poi-Ngian 국제구조공학회 2019 Smart Structures and Systems, An International Jou Vol.24 No.4

Construction development and greenhouse gas emissions have globally required a strategic management to take some steps to stain and maintain the environment. Nowadays, recycled aggregates, in particular ceramic waste, have been widely used in concrete structures due to the economic and environmentally friendly solution, requiring the knowledge of recycled concrete. Also, one of the materials used as a substitute for concrete cement is wollastonite mineral to decrease carbon dioxide (CO2) from the cement production process by reducing the concrete consumption in concrete. The purpose of this study is to investigate the effect of wollastonite on the mechanical properties and durability of conventional composite concrete, containing recycled aggregates such as compressive strength, tensile strength (Brazilian test), and durability to acidic environment. On the other hand, in order to determine the strength and durability of the concrete, 5 mixing designs including different wollastonite values and recovered aggregates including constant values have been compared to the water - cement ratio (w/c) constant in all designs. The experimental results have shown that design 5 (containing 40% wollastonite) shows only 6.1% decrease in compressive strength and 4.9% decrease in tensile strength compared to the control plane. Consequently, the use of wollastonite powder to the manufacturing of conventional structural concrete containing recycled ceramic aggregates, in addition to improving some of the properties of concrete are environmentally friendly solutions, providing natural recycling of materials.

Experimental investigation on the effect of cementitious materials on fresh and mechanical properties of self-consolidating concrete

Shariati, Mahdi,Rafie, Shervin,Zandi, Yousef,Fooladvand, Rouhollah,Gharehaghaj, Behnam,Mehrabi, Peyman,Shariat, Ali,Trung, Nguyen Thoi,Salih, Musab N.A.,Poi-Ngian, Shek Techno-Press 2019 Advances in concrete construction Vol.8 No.3

Although applying self-consolidating concrete (SCC) in many modern structures is an inevitable fact, the high consumption of cement in its mixing designs has led to increased production costs and adverse environmental effects. In order to find economically viable sources with environmentally friendly features, natural pozzolan pumice and blast furnace slag in 10-50% of replacement binary designs have been investigated for experiments on the properties of fresh concrete, mechanical properties, and durability. As a natural pozzolan, pumice does not require advanced equipment to prepare for consumption and only needs to be powdered. Pumice has been the main focus of this research because of simple preparation. Also to validate the results, in addition to the control specimens of each design, fly ash as a known powder has been evaluated. Moreover, ternary mixes of pumice and silica fume were investigated to enhance the obtained results of binary mixes. It was concluded that pumice and slag powders indicated favorable performance in the high percentage of replacement.

Application of Extreme Learning Machine (ELM) and Genetic Programming (GP) to design steel-concrete composite floor systems at elevated temperatures

Mahdi Shariati,Mohammad Saeed Mafipour,Peyman Mehrabi,Yousef Zandi,Davoud Dehghani,Alireza Bahadori,Ali Shariati,Nguyen Thoi Trung,Musab N.A. Salih,Shek Poi-Ngian 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.33 No.3

This study is aimed to predict the behaviour of channel shear connectors in composite floor systems at different temperatures. For this purpose, a soft computing approach is adopted. Two novel intelligence methods, including an Extreme Learning Machine (ELM) and a Genetic Programming (GP), are developed. In order to generate the required data for the intelligence methods, several push-out tests were conducted on various channel connectors at different temperatures. The dimension of the channel connectors, temperature, and slip are considered as the inputs of the models, and the strength of the connector is predicted as the output. Next, the performance of the ELM and GP is evaluated by developing an Artificial Neural Network (ANN). Finally, the performance of the ELM, GP, and ANN is compared with each other. Results show that ELM is capable of achieving superior performance indices in comparison with GP and ANN in the case of load prediction. Also, it is found that ELM is not only a very fast algorithm but also a more reliable model.