TENSILE BEHAVIOR OF BOLTED TIMBER COMPOSITE HALF-LAP CONNECTION FOR KERUING AND SESENDOK

2016 ◽  
Vol 78 (5-4) ◽  
Author(s):  
Nurain Rosdi ◽  
Mohd Hanafie Yasin ◽  
Mohd Hazim Mohd Azam ◽  
Rohana Hassan

Over recent years, half-lap connection is widely used all over the world to provide longer structural member due to limited size of sawn timber in construction industries. Timber connected in joints may reduce overall mechanical properties of the structure. This paper present finding on a series of connection of half lap bolted joint member from Keruing (SG5) and Sesendok (SG7) timber species. The half-lap connection were subjected to tensile test and reinforced with GFRP sheet that were conducted until failure to determine their tensile behavior. The results showed that the GFRP help to increase the load carrying capacity of all the timber specimens especially timber species that lies in a weak strength group for almost 30 % by strength.

2020 ◽  
Vol 54 (26) ◽  
pp. 4025-4034
Author(s):  
Chang Xu ◽  
Wenjing Wang ◽  
Zhiming Liu ◽  
Chen Fu

As the weakness zone of composite structures, joints are of great concern. Adding fasteners in the bonded joint is another type of jointing, technology used in engineering. In this research, considering a new type of flat-joggle-flat carbon fibre reinforced plastic (CFRP) joint, a prediction model based on the commercial software ABAQUS was proposed to predict the joint load carrying capacity and analyse the joint failure modes. Tensile tests were performed to verify the validity of the model. Furthermore, the orthogonal design was applied to explore the effects of four kinds of factors on the hybrid joints. The results showed that the load-carrying capacity of the hybrid joint improved by 40.5% and 31.9% on average, compared with that of the adhesively bonded joint and the bolted joint, respectively. The carrying capacity for the bonded joint, bolted joint and hybrid joint predicted by the model has error values of 3.5%, 2.7% and 3.1%, respectively, which illustrates good accuracy with the test results. The width-to-diameter ratio appears to have the most substantial effect on the first drop load and the maximum load of the hybrid joint. The failure modes are influenced by the width-to-diameter ratio, edge-to-diameter ratio and stacking sequence.


Glass fibre reinforcement polymers (GFRP) application for reinforcement of wood, concrete and steel member is relatively becoming more variety in construction applications. Although it is possible to build large monolithic structures with composite materials, there are still several reasons for the structure to fail. One of the main reasons that contribute to this failure is the connection performance due to its function in carrying load across the structure. Thus having the right fundamental data for connection design purposes according to the specific and technological upgraded materials is very important. One of the basic methodologies in gaining the design data is through experimental double shear test which can be verified by European Yield Model (EYM) theory. Therefore, the objective of this research is to determine the load carrying capacity of double shear strength behaviour connections made of Kempas timber species as the main member and dowelled by the GFRP or the Kempas rod. The specimens were tested under the shear load with 2mm/min rate and tested until failure. From the experiment, it was found that the average ultimate shear strength of member dowelled with GFRP rod is 21.36% higher compared to one doweled with Kempas rod. According to mode of failure between two types of bolt, GFRP dowelled performs well (Mode I& IV) rather than Kempas dowelled (Mode IV).


Author(s):  
V. Bogaert

<p>The Floraliahall in Ghent was built during 1912-1913 as part of a series of large infrastructure works for the world exposition of 1913. The main structure of the hall consists of 18 portal frames having 3 spans of 10.16, 40.18 and 10.16 m. The upper part of the structure is highly slender. Adversely to the customary concepts of 100 years ago, the lighter frames at 7.45 m distance, are hinged twice at the springs, whereas the more heavy frames, at 15 m distance, are completely clamped at their base. In addition, measurements show that crosssections of compressed parts have larger area than the tensile parts. From the structural point of view, these frames sometimes have an unexpected composition. The aim was to determine whether this structure can comply with contemporary requirements and codes. From measurements and simulations follows that in limited areas high stresses appear, unacceptable even in serviceability state. This may be partly due to modifications of the roof that were made inappropriately, from the uncertainty to assess certain details with the model and from ineffective analysis at the time of construction.</p>


Author(s):  
Jisha S

In the medium to high seismic zone, spun pile for structural foundation should be designed with elastic behaviour due to low ductility and dissipated energy. Spun pile is also termed as prestressed hollow concrete pile (PHC). Spun pile is one of the types of piles are widely used in the world construction, for example in building and bridge. However, it is important to note that spun piles have limited ductility so that they are not intended to response inelastically during major earthquakes. spun piles behave brittle manner in both axial force domination and flexural moment domination. Recently spun piles are commonly used directly as the piers of elevated slab such as viaduct called pile-supported slab viaduct (PSSV). In this paper the hollow spun pile is infilled with concrete and concentric load analysis is carried out. Then comparing the axial load carrying capacity of hollow and concrete infilled spun pile.


Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1704 ◽  
Author(s):  
Ramon Silva ◽  
Welington V. Silva ◽  
Jonas Yamashita de Farias ◽  
Marcos Aires A. Santos ◽  
Leonardo O. Neiva

This paper carries out the assessment of load-carrying capacity of prestressed concrete sleepers, in accordance with Brazilian Standard (ABNT NBR 11709) and AREMA Standard. In a lot of railways around the world, many prestressed concrete sleepers have failed due to Rail Seat Abrasion (RSA) and corrosion. RSA is the wear degradation underneath the rail on the surface of prestressed concrete sleepers. In this paper, a numerical study was carried out to evaluate the load-carrying capacity of the prestressed concrete sleepers, using ABAQUS software. The nonlinear using Concrete Damage Plasticity model was validated by 18 experimental results, in accordance to standards. Using the validated model, the influence of different wear depth RSA, combined with corrosion of the prestressed wires, is investigated.


2012 ◽  
Vol 178-181 ◽  
pp. 2412-2417
Author(s):  
Rui Juan Jiang ◽  
Qi Ming Wu ◽  
Yi Yan Chen ◽  
Xiao Wei Yi ◽  
Jun Tu

In EN1991-1-7 Eurocode 1: Part 1-7 Accidental Actions structural robustness is defined as ‘the ability of a structure to withstand events like fire, explosions, impact or consequences of human error without being damaged to an extent disproportionate to the original cause’. Accordingly, the principle of structural robustness is that local damage is acceptable, provided that it will not endanger the structure and that the overall load-carrying capacity is maintained during an appropriate length of time to allow the necessary emergency measures to be taken. For different structures the practical ways to achieve robustness are different. Lots of through arch bridges with hangers have been built throughout the world. However, the structural collapse may happen due to the hanger's damage or failure if the bridge is not designed appropriately. In this paper, the structural robustness of the through arch bridges with vertical hangers are discussed and verified by an example. Based on this study, a few practical suggestions are put forward to achieve the structural robustness for the future through arch bridges' design.


Bauingenieur ◽  
2020 ◽  
Vol 95 (05) ◽  
pp. 174-179
Author(s):  
Philippe Van Bogaert

ABSTRACT The Floraliahall in Ghent was built during 1912 and 1913 as part of a series of large infrastructure works for the world exposition of 1913. The main structure of the hall consists of 18 portal frames having three spans of 10.16 m, 40.18 m and 10.16 m. The upper part of the structure is highly slender. Adversely to the customary concepts of 100 years ago, the lighter frames at 7.45 m distance, are hinged twice at the springs, whereas the more heavy frames, at 15 m distance, are completely clamped at their base. In addition, measurements show that cross-sections of compressed parts have larger area than the tensile parts. From the structural point of view, these frames sometimes have an unexpected composition. The aim was to determine whether this structure can comply with contemporary requirements and codes. From measurements and simulations follows that in limited areas high stresses appear, unacceptable even in serviceability state. This may be partly due to modifications of the roof that were made inappropriately, from the uncertainty to assess certain details with the model and from ineffective analysis at the time of construction. ZUSAMMENFASSUNG Die Floraliahalle in Gent wurde zwischen 1912 und 1913 als Teil einer Reihe großer Infrastrukturarbeiten für die Weltausstellung von 1913 errichtet. Die Hauptstruktur der Halle besteht aus 18 Portalrahmen mit drei Feldern von 10,16 m, 40,18 m und 10,16 m. Der obere Teil der Struktur ist sehr schlank. Im Gegensatz zu den vor 100 Jahren üblichen Konzepten sind die leichteren Rahmen in einem Abstand von 7,45 m gelenkig aufgelagert, während die schwereren Rahmen in einem Abstand von 15 m vollständig an ihrer Basis eingespannt sind. Außerdem zeigen Messungen, dass Querschnitte von druckbeanpruchten Teilen eine größere Fläche aufweisen als die Zugteile. Vom strukturellen Standpunkt aus haben diese Rahmen manchmal eine unerwartete Zusammensetzung. Ziel war es festzustellen, ob diese Struktur den heutigen Anforderungen und Normen entspricht. Aus Messungen und Simulationen geht hervor, dass in begrenzten Bereichen hohe Beanspruchungen auftreten, die auch im Gebrauchstauglichkeitszustand nicht akzeptabel sind. Dies kann zum Teil auf unsachgemäß vorgenommene Änderungen des Daches, auf die Unsicherheit, bestimmte Details mit dem Modell zu bewerten, und auf eine ineffektive Analyse zum Zeitpunkt des Baus zurückzuführen sein.


2005 ◽  
Vol 10 (2) ◽  
pp. 151-160 ◽  
Author(s):  
J. Kala ◽  
Z. Kala

Authors of article analysed influence of variability of yield strength over cross-section of hot rolled steel member to its load-carrying capacity. In calculation models, the yield strength is usually taken as constant. But yield strength of a steel hot-rolled beam is generally a random quantity. Not only the whole beam but also its parts have slightly different material characteristics. According to the results of more accurate measurements, the statistical characteristics of the material taken from various cross-section points (e.g. from a web and a flange) are, however, more or less different. This variation is described by one dimensional random field. The load-carrying capacity of the beam IPE300 under bending moment at its ends with the lateral buckling influence included is analysed, nondimensional slenderness according to EC3 is λ¯ = 0.6. For this relatively low slender beam the influence of the yield strength on the load-carrying capacity is large. Also the influence of all the other imperfections as accurately as possible, the load-carrying capacity was determined by geometrically and materially nonlinear solution of very accurate FEM model by the ANSYS programme.


2005 ◽  
Vol 10 (1) ◽  
pp. 65-75 ◽  
Author(s):  
Z. Kala

The load-carrying capacity of the member with imperfections under axial compression is analysed in the present paper. The study is divided into two parts: (i) in the first one, the input parameters are considered to be random numbers (with distribution of probability functions obtained from experimental results and/or tolerance standard), while (ii) in the other one, the input parameters are considered to be fuzzy numbers (with membership functions). The load-carrying capacity was calculated by geometrical nonlinear solution of a beam by means of the finite element method. In the case (ii), the membership function was determined by applying the fuzzy sets, whereas in the case (i), the distribution probability function of load-carrying capacity was determined. For (i) stochastic solution, the numerical simulation Monte Carlo method was applied, whereas for (ii) fuzzy solution, the method of the so-called α cuts was applied. The design load-carrying capacity was determined according to the EC3 and EN1990 standards. The results of the fuzzy, stochastic and deterministic analyses are compared in the concluding part of the paper.


2005 ◽  
Vol 33 (4) ◽  
pp. 210-226 ◽  
Author(s):  
I. L. Al-Qadi ◽  
M. A. Elseifi ◽  
P. J. Yoo ◽  
I. Janajreh

Abstract The objective of this study was to quantify pavement damage due to a conventional (385/65R22.5) and a new generation of wide-base (445/50R22.5) tires using three-dimensional (3D) finite element (FE) analysis. The investigated new generation of wide-base tires has wider treads and greater load-carrying capacity than the conventional wide-base tire. In addition, the contact patch is less sensitive to loading and is especially designed to operate at 690kPa inflation pressure at 121km/hr speed for full load of 151kN tandem axle. The developed FE models simulated the tread sizes and applicable contact pressure for each tread and utilized laboratory-measured pavement material properties. In addition, the models were calibrated and properly validated using field-measured stresses and strains. Comparison was established between the two wide-base tire types and the dual-tire assembly. Results indicated that the 445/50R22.5 wide-base tire would cause more fatigue damage, approximately the same rutting damage and less surface-initiated top-down cracking than the conventional dual-tire assembly. On the other hand, the conventional 385/65R22.5 wide-base tire, which was introduced more than two decades ago, caused the most damage.


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