Experimental Tests on Extended End-Plate Connections with Variable Parameters

Mahmood Md Tahir1,Md Azman Hussein 한국강구조학회 2008 International Journal of Steel Structures Vol.8 No.4

Typically, steel frames are designed either using the approach of pin joint for simple construction or rigid joint for continuous construction. However, in actual situation most of connections are classified as semi-rigid joint or partial strength which has been recognised and encouraged by Eurocode 3 in semi-continuous construction. Eight experimental tests have been carried out for extended end-plate connections consist of variable parameters such as size and thickness of end-plate, size and number of bolts, size of columns, and beams. The tests were set-up using local hot-rolled steel sections known as Perwaja sections for both beams and columns instead of typical British sections. Geometric parameters such as the thickness of end-plate, the number and size of bolts and the use of deeper beam have contributed significantly to the increase in moment resistance and stiffness of the connections. The study concluded that all the tested extended end-plate connections are eligible to be classified as partial strength connections and the results of maximum moment resistance showed good agreement between experimental and predicted component method in most cases.

Comparison of Component Method with Experimental Tests for Flush End-Plate Connections using Hot-Rolled Perwaja Steel Sections

Mahmood Md. Tahir,Mohd Azman Hussein,Arizu Sulaiman,Shahrin Mohamed 한국강구조학회 2009 International Journal of Steel Structures Vol.9 No.2

A component method has been introduced by Steel Construction Institute to predict the moment resistance of partial strength connection. The design philosophy is taken directly from Eurocode 3 with strength checks on bolts, welds, and steel which have been modified to comply with BS 5950-1:2000. The accuracy of the method however needs to be validated with the experimental tests especially for hot-rolled sections other than typical British Section (BS). Six experimental tests on beamto- column connections have been carried out for Flush End-Plate (FEP) connections consisting of variable parameters such as thickness of end-plate, size and number of bolts, size of columns, and beams. The tests were set-up using local hot-rolled steel sections known as Perwaja Section (PS) for beams and columns instead of typical British Section (BS). The strength of materials for end-plate, column and beam sections were tested for tensile strength and used in predicting the moment resistance for component method. The moment versus rotation of the test results were plotted and compared with the moment resistance derived from component method. The study concluded that the moment resistance of the tested flush end-plate connections was higher than the predicted moment resistance from component method which showed good agreement between the two moments. The study also concluded that the tested FEP connections met the requirements and criteria of partial strength connections. A component method has been introduced by Steel Construction Institute to predict the moment resistance of partial strength connection. The design philosophy is taken directly from Eurocode 3 with strength checks on bolts, welds, and steel which have been modified to comply with BS 5950-1:2000. The accuracy of the method however needs to be validated with the experimental tests especially for hot-rolled sections other than typical British Section (BS). Six experimental tests on beamto- column connections have been carried out for Flush End-Plate (FEP) connections consisting of variable parameters such as thickness of end-plate, size and number of bolts, size of columns, and beams. The tests were set-up using local hot-rolled steel sections known as Perwaja Section (PS) for beams and columns instead of typical British Section (BS). The strength of materials for end-plate, column and beam sections were tested for tensile strength and used in predicting the moment resistance for component method. The moment versus rotation of the test results were plotted and compared with the moment resistance derived from component method. The study concluded that the moment resistance of the tested flush end-plate connections was higher than the predicted moment resistance from component method which showed good agreement between the two moments. The study also concluded that the tested FEP connections met the requirements and criteria of partial strength connections.

A SUBCLASS OF ANALYTIC FUNCTIONS DEFINED BY USING MITTAG-LEFFLER FUNCTION

( Tahir Mahmood ),( Muhammad Naeem ),( Saqib Hussain ),( Shahid Kjan ),( Şahsene Altinkaya ) 호남수학회 2020 호남수학학술지 Vol.42 No.3

In this paper, new subclasses of analytic functions are proposed by using Mittag-Leffler function. Also some properties of these classes are studied in regard to coefficient inequality, distortion theorems, extreme points, radii of starlikeness and convexity and obtained numerous sharp results.

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.

Experimental Tests on Composite and Non-composite Connections Using Trapezoid Web Profiled Steel Sections

Mahmood Md Tahir,Sulaiman A,Anis S 한국강구조학회 2008 International Journal of Steel Structures Vol.8 No.1

The use of partial strength or semi-rigid connections has been encouraged by Eurocode 3 and studies on the mater knownas semi-continuous construction have proven that substantial savings in steel weight of the overall construction. The objectiveof this paper is to present the performance of the strength, the rotational stifness, and the ductility of the composite connectionsand non-composite conection using trapezoidal web profiled steel (TWP) sections. Eight full scales testing of beam-to-columnconfigurations have ben carried out. The tests results showed good agreement betwen the experimental and the predictedvalues. The test also concluded that composite connections have higher moment resistance, higher stiffness, and less ductilecompared with the non-composite connections. The size of TWP steel section should be limited to 50m deep for bothcomposite and non-composite connections.

LATTICE ORDERED SOFT NEAR RINGS

Mahmood, Tahir,Rehman, Zia Ur,Sezgin, Aslihan The Kangwon-Kyungki Mathematical Society 2018 한국수학논문집 Vol.26 No.3

Keeping in view the expediency of soft sets in algebraic structures and as a mathematical approach to vagueness, in this paper the concept of lattice ordered soft near rings is introduced. Different properties of lattice ordered soft near rings by using some operations of soft sets are investigated. The concept of idealistic soft near rings with respect to lattice ordered soft near ring homomorphisms is deliberated.

Antioxidant potential of a soft cheese (paneer) supplemented with the extracts of date (Phoenix dactylifera L.) cultivars and its whey

Tahir Mahmood Qureshi,Aniqa Amjad,Muhammad Nadeem,Mian Anjum Murtaza,Masooma Munir 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.10

Objective: The present study was conducted to evaluate the antioxidant potential of paneer, a soft cheese supplemented with various water soluble date extracts during storage. Further, the whey obtained from all the paneer samples was also investigated for its antioxidant potential. Methods: The date cultivars were evaluated for their physico-chemical characteristics and date extracts were assessed for their antioxidant potential. Physico-chemical evaluation, microbiological quality and further antioxidant potential of the prepared paneer were carried out during storage period (0 to 8 days, 5°C). Results: All the date extracts were found to have considerable antioxidant activity due to presence of total phenolics and flavonoids. Owing to the presence of phenolics and flavoinds in date extracts, supplemented paneer showed higher trolox equivalent antioxidant capacity, reducing power and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity than control paneer. Paneer supplemented with Rabi extracts had the highest total phenolics (190.7 μg gallic acid equivalent/g paneer), DPPH radical scavenging activity (928.1 μmol equivalent of Trolx/g paneer) and trolox equivalent antioxidant capacity (9.2 μmol equivalent of Trolx/g paneer). The whey obtained from control paneer showed lower values of total phenolics, total flavonoids, DPPH, trolox equivalent antioxidant capacity and reducing power as compared to the values of whey obtained from paneer supplemented with date extracts. Conclusion: Paneer supplemented with date extracts and its whey may offer potent antioxidant activity.

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.

Performance of partial strength connection connected by thick plate between column flanges

Mahmood M. Tahir,Irwan Juki,Mohd Y. Ishak,Shahrin Mohammad,Abdullah Z. Awang,Roger Plank 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.51 No.2

Traditional beam connections to the minor axis of a column have relatively low strength and stiffness. A modified detail, using a plate welded between the toes of the column flange - referred to as a toe plate connection - is examined in this paper. The results of an experimental investigation for both flush and extended end-plate connections connected to a 25 mm thick end-plate are presented. The tests are complemented by finite element modelling which compares very well with the test observations. The results show a significant increase in both moment resistance and initial stiffness for this connection detail compared with connections made directly to the column web. This offers the prospect of more optimal solutions taking advantage of partial strength frame design for the minor axis as well as major axis.

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.