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Full-Text Articles in Engineering
Comparative Behaviour Of Frp Confined Square Concrete Columns Under Eccentric Loading, X Lei, Thong M. Pham, M N. S Hadi
Comparative Behaviour Of Frp Confined Square Concrete Columns Under Eccentric Loading, X Lei, Thong M. Pham, M N. S Hadi
Faculty of Engineering - Papers (Archive)
This study evaluates different methods of strengthening existing square concrete columns under eccentric loading. Sixteen reinforced square concrete columns were cast. The columns were made from normal strength concrete and the reinforcement was kept at minimum simulating columns needing retrofitting. Four columns were modified with round comers and wrapped with three layers of CFRP, four were circularised by circular segments and wrapped with three layers of CFRP, and the last four columns were circularised and confined with steel straps. Specimens from each group were tested under concentric, eccentric (15 or 25 mm) and flexural bending. Results from the study showed …
A Laboratory Study Of Railway Ballast Behaviour Under Various Fouling Degree, Cholachat Rujikiatkamjorn, Buddhima Indraratna, Ngoc Trung Ngo, Matthew Coop
A Laboratory Study Of Railway Ballast Behaviour Under Various Fouling Degree, Cholachat Rujikiatkamjorn, Buddhima Indraratna, Ngoc Trung Ngo, Matthew Coop
Faculty of Engineering - Papers (Archive)
This paper presents a laboratory study of interface behavior between ballast and geogrid under various degree of fouling by coal fines. The stress-displacement behaviour of fresh and fouled ballast with geogrid was investigated through a series of large-scale direct shear tests where the fouling degree varied from 0% to 95% Void Contamination Index (VCI), at normal stresses ranging from 15kPa to 75kPa. The results showed that geogrid enhances the shear strength and increases apparent angle of shearing resistance, while only slightly reduces the vertical displacement of the composite geogrid-ballast system. However, when ballast was contaminated by coal fines, the influences …
Performance Analysis Of Distribution Networks Under High Penetration Of Solar Pv, M J. E Alam, Kashem M. Muttaqi, Darmawan Sutanto, L Elder, A Baitch
Performance Analysis Of Distribution Networks Under High Penetration Of Solar Pv, M J. E Alam, Kashem M. Muttaqi, Darmawan Sutanto, L Elder, A Baitch
Faculty of Engineering and Information Sciences - Papers: Part A
Integration of solar photovoltaic (PV) resources into distribution networks changes the normally expected network behaviour by injecting real power into the point of connection. Depending on the characteristics and setup of the PV inverter, reactive power could also be injected into the network. The impact will depend on the control strategy adopted for reactive power injection. Typically, solar PV units are installed at low voltage (LV) level in distribution networks. Cluster based installation of numerous PV inverters in the LV level will impact the operation of both the host LV network and the upstream medium voltage network. With random variations …
Evolution Of Internal Crack In Bcc Fe Under Compressive Loading, Dongbin Wei, Zhengyi Jiang, Jingtao Han
Evolution Of Internal Crack In Bcc Fe Under Compressive Loading, Dongbin Wei, Zhengyi Jiang, Jingtao Han
Faculty of Engineering and Information Sciences - Papers: Part A
A molecular dynamics model has been developed to investigate the evolution of the internal crack of nano scale during heating or compressive loading in BCC Fe. The initial configuration does not contain any pre-existing dislocations. In the case of heating, temperature shows a significant effect on crack evolution and the critical temperature at which the crack healing becomes possible is 673 K. In the case of compressive loading, the crack can be healed at 40 K at a load- ing rate 0.025 × 1018 Pa·m1/2/s in 6 × 10−12 s. The diffusion of Fe atoms into the crack area results …
Behaviour Of Frp Confined Concrete Cylinders Under Different Temperature Exposure, Muhammad N. S Hadi, B A. Louk Fanggi
Behaviour Of Frp Confined Concrete Cylinders Under Different Temperature Exposure, Muhammad N. S Hadi, B A. Louk Fanggi
Faculty of Engineering - Papers (Archive)
Bridge structures are exposed to the elements with a high variation in temperature. The purpose of this study is to investigate the effect of different high temperatures on the behaviour of concrete cylinders wrapped with Fibre Reinforced Polymer (FRP). Twelve concrete cylinders made of 60 MPa having 100 mm diameter and 200 mm height were cast and tested. The cylinders were divided into four groups: cylinders wrapped with a single CFRP layer, cylinders wrapped with two CFRP layers, cylinders wrapped with a single GFRP layer, and cylinders wrapped with two GFRP layers. Each group was exposed to temperatures of 20°C, …
Stress-Strain Model For Concrete Under Cyclic Loading, Farhad Aslani, Raha Jowkarmeimandi
Stress-Strain Model For Concrete Under Cyclic Loading, Farhad Aslani, Raha Jowkarmeimandi
Faculty of Engineering - Papers (Archive)
A hysteretic stress-strain model is developed for unconfined concrete with the intention of providing efficient modelling for the structural behaviour of concrete in seismic regions. The proposed model is based on the findings of previous experimental and analytical studies. The model for concrete subjected to monotonic and cyclic loading comprises four components in compression and tension - an envelope curve (for monotonic and cyclic loading), an unloading curve, a reloading curve and a transition curve. Formulations for partial unloading and partial reloading curves are also presented. The reliability of the proposed constitutive model is investigated for a reinforced concrete member …
Behaviour Of Cfrp Wrapped Square Rc Columns Under Eccentric Loading, X Lei, Thong M. Pham, Muhammad N. S Hadi
Behaviour Of Cfrp Wrapped Square Rc Columns Under Eccentric Loading, X Lei, Thong M. Pham, Muhammad N. S Hadi
Faculty of Engineering - Papers (Archive)
Fibre Reinforced Polymer (FRP) is an excellent material to strengthen existing structures. However, the confinement efficiency of FRP-confined square columns is relatively low compared to circular columns due to stress concentration at the sharp corners. This paper presents a new technique aimed to maximise the efficiency of FRP confinement for square concrete columns: circularisation using segmental circular concrete covers. Sixteen square reinforced concrete columns were cast. Four were used as a reference group; four were rounded 20 mm at each corner and wrapped with three layers of CFRP simulating the conventional methods; the rest eight columns were bonded with four …
Shear Behaviour Of Rock Joints Under Cyclic Loading, Buddhima Indraratna, Ali Mirzaghorbanali, David Oliveira, Wuditha N. Premadasa
Shear Behaviour Of Rock Joints Under Cyclic Loading, Buddhima Indraratna, Ali Mirzaghorbanali, David Oliveira, Wuditha N. Premadasa
Faculty of Engineering - Papers (Archive)
For the design of civil and mining engineering geo-structures, it is often necessary to investigate the behaviour and the role of discontinuities on the rock mass performance. In many cases, failure is governed by the shear behaviour of discontinuities in excavations. In this context, evaluation of the effects of small repetitive earthquakes on the shear strength parameters of rock joints especially in tunnels and dam foundations is also important. This paper presents the results of a systematic study carried out on the cyclic shear behaviour of artificial rock joints under constant normal stiffness (CNS) conditions, as many of the previous …
The Effect Of The Strain Rate On Soft Soil Behaviour Under Cyclic Loading, Jing Ni, Buddhima Indraratna, X Y. Geng, Cholachat Rujikiatkamjorn
The Effect Of The Strain Rate On Soft Soil Behaviour Under Cyclic Loading, Jing Ni, Buddhima Indraratna, X Y. Geng, Cholachat Rujikiatkamjorn
Faculty of Engineering - Papers (Archive)
In this paper, cyclic triaxial loading tests were conducted on specimens of soft clay with varying cyclic stresses and frequencies to investigate the performance of soft soil subgrade subjected to cyclic loading. The laboratory results indicate that given the same level of cyclic stress, the stability of clay subgrade is primarily dependent on the loading time with no consistent frequency/train speed effect. There exists a critical level of cyclic stress between 60 and 80% of the monotonic shear strength, above which failure may occur regardless of the loading frequency. The nature that soils behave dependently on cyclic stress level rather …
Behaviour Of Cfrp Wrapped Square Rc Columns Under Eccentric Loading, Xu Lei, Thong Minh Pham, Muhammad N. Hadi
Behaviour Of Cfrp Wrapped Square Rc Columns Under Eccentric Loading, Xu Lei, Thong Minh Pham, Muhammad N. Hadi
Faculty of Engineering and Information Sciences - Papers: Part A
Fibre Reinforced Polymer (FRP) is an excellent material to strengthen existing structures. However, the confinement efficiency of FRP - confined square columns is relatively low compared to circular columns due to stress concentration at the sharp corners. This paper presents a new techniqu e aimed to maximise the efficiency of FRP confinement for square concrete columns : circularisation using segmental circular concrete covers . Sixteen square reinforced concrete columns were cast. Four were used as a reference group; four were rounded 20 mm at each corner and wrapped with three layers of CFRP simulating the conventional methods; the rest eight …
Non-Uniform Stress Distribution In Frp-Wrapped Circular Concrete Columns Under Uniform Axial Deformation, S Q. Li, J F. Chen, Tao Yu, J G. Teng
Non-Uniform Stress Distribution In Frp-Wrapped Circular Concrete Columns Under Uniform Axial Deformation, S Q. Li, J F. Chen, Tao Yu, J G. Teng
Faculty of Engineering and Information Sciences - Papers: Part A
The confinement of concrete columns using bonded FRP wraps has become a popular retrofit technique. Through extensive research in the last two decades, many stress-strain models have been developed for concrete in FRP-wrapped circular columns. All these models assume that the stress state is axisymmetric in an FRP-wrapped circular concrete column under concentric axial compression. This implies that the FRP wrap is assumed to be axisymmetric in geometry, but in reality such axisymmetry is not realised due to the existence of an overlapping zone. This paper presents a finite element investigation into the stress state in FRP-wrapped circular concrete columns …