Papers by Muhammad Abbassi
Finite element analysis A 2D finite element analysis for the numerical prediction of capacity cur... more Finite element analysis A 2D finite element analysis for the numerical prediction of capacity curve of unreinforced masonry (URM) walls is conducted. The studied model is based on the fiber finite element approach. The emphasis of this paper will be on the errors obtained from fiber finite element analysis of URM structures under pushover analysis. The masonry material is modeled by different constitutive stress-strain model in compression and tension. OpenSees software is employed to analysis the URM walls. Comparison of numerical predictions with experimental data, it is shown that the fiber model employed in OpenSees cannot properly predict the behavior of URM walls with balance between accuracy and low computational efforts. Additionally, the finite element analyses results show appropriate predictions of some experimental data when the real tensile strength of masonry material is changed. Hence, from the viewpoint of this result, it is concluded that obtained results from fiber...
AFRICAN JOURNAL OF BIOTECHNOLOGY, 2012
Randomly amplified polymorphic DNA primers (RAPDs) were mapped on chromosomes 2A of wheat genotyp... more Randomly amplified polymorphic DNA primers (RAPDs) were mapped on chromosomes 2A of wheat genotypes using "Chinese Spring" nullisomic-tetrasomic lines. One particular pair of chromosome was absent and another homologous pair was present in the extra dose. Genomic DNA was isolated from two genetic stocks viz; NT1D1B and NT2A2B. Polymerase chain reaction (PCR) were conducted using RAPD primers GLC-07 and GLB-11. PCR amplification using primer GLC-07 produced single band of approximately 1100 bp in both the genetic stocks, indicating that the primer was annealed to a loci other than chromosome 2A. RAPD primer GLB-11 amplified a polymorphic allele of approximately 500 bp which was present in NT1D1B but was absent in NT2A2B, indicating that the locus was present on chromosome 2A of common wheat. Hence, this marker (GLB-11) can reliably be used to keep track of chromosome 2A of wheat.
Journal of Rehabilitation in Civil Engineering, 2014
Fiber reinforced Polymers (FRP) have widely used for the purposes of enhances strength and ductil... more Fiber reinforced Polymers (FRP) have widely used for the purposes of enhances strength and ductility of concrete columns. Proper design of such hybrid columns, however, requires a better recognition of the behavior of concrete columns confined with FRP. In this paper, the influence of FRP thickness, concrete compressive strength, and column size on the performance of eccentrically loaded reactive powder concrete (RPC) columns confined with FRP is investigated. In this regard, five different FRP thicknesses, three types of column sizes, and concrete compressive strength values ranging from 140 MPa to 180 MPa are considered. For this purpose, two-dimensional nonlinear finite element analyses are carried out so as to predict the behavior of FRP-confined RPC columns. OpenSees software is employed to analyze the considered columns. To validate finite element model, the numerical predictions are compared with the experimental data. The study, from a numerical point of view, derived some i...
Slovak Journal of Civil Engineering, 2019
In this research, which is based on the finite element method, the behavior of reactive powder co... more In this research, which is based on the finite element method, the behavior of reactive powder concrete (RPC) columns confined with fiber-reinforced polymer (FRP) under seismic excitation is investigated. The governing theory in the numerical simulation is based on the fiber finite element method. The adequacy of the fiber model in predicting the response of FRP-confined RPC columns is validated through comparisons with the available experimental results. To study the seismic behavior of FRP-confined RPC columns, the fiber model presented was subjected to different earthquakes. In this regard, four ground acceleration time histories with different peak accelerations were applied to investigate the response of FRP-confined RPC columns. The results show that reactive powder concrete columns confined with FRP exhibit an acceptable seismic performance. The investigation also confirms that RPC-confined columns show a high degree of ductility. Additionally, the load capacity (maximum late...
Journal of Mechanical Engineering and Sciences
Numerous finite element methods have been widely used to predict the response of normal/high stre... more Numerous finite element methods have been widely used to predict the response of normal/high strength concrete columns confined with Fiber Reinforced Polymer (FRP) under different loading conditions. In this regard, simulating the response of FRP-confined reactive powder concrete (RPC) columns has been less emphasized. The present study aimed to propose a finite element model based on fiber finite element methodology in order to predict the behavior of FRP confined RPC columns under axial compressive load with different eccentricities. The columns were modeled with a nonlinear beam-column element with two nodes with distributed plasticity. In addition, the proposed finite element model in the present study indicated its simplicity, low computational efforts, and flexibility by adopting a perfect bond between RPC and FRP. Further, the obtained results from the finite element analysis were compared to those from available tested specimens. Based on the comparisons, the proposed model ...
In this research, which is based on the finite element method , the behavior of reactive powder c... more In this research, which is based on the finite element method , the behavior of reactive powder concrete (RPC) columns confined with fiber-reinforced polymer (FRP) under seismic excitation is investigated. The governing theory in the numerical simulation is based on the fiber finite element method. The adequacy of the fiber model in predicting the response of FRP-confined RPC columns is validated through comparisons with the available experimental results. To study the seismic behavior of FRP-confined RPC columns, the fiber model presented was subjected to different earthquakes. In this regard, four ground acceleration time histories with different peak accelerations were applied to investigate the response of FRP-confined RPC columns. The results show that reactive powder concrete columns confined with FRP exhibit an acceptable seismic performance. The investigation also confirms that RPC-confined columns show a high degree of ductility. Additionally, the load capacity (maximum lateral load) is increased , and the concrete's compressive strength is increased.
Fiber reinforced Polymers (FRP) have widely used for the purposes of enhances strength and ductil... more Fiber reinforced Polymers (FRP) have widely used for the purposes of enhances strength and ductility of concrete columns. Proper design of such hybrid columns, however, requires a better recognition of the behavior of concrete columns confined with FRP. In this paper, the influence of FRP thickness, concrete compressive strength, and column size on the performance of eccentrically loaded reactive powder concrete (RPC) columns confined with FRP is investigated. In this regard, five different FRP thicknesses, three types of column sizes, and concrete compressive strength values ranging from 140 MPa to 180 MPa are considered. For this purpose, two-dimensional nonlinear finite element analyses are carried out so as to predict the behavior of FRP-confined RPC columns. OpenSees software is employed to analyze the considered columns. To validate finite element model, the numerical predictions are compared with the experimental data. The study, from a numerical point of view, derived some important relevant conclusions regarding the behavior of RPC columns confined with FRP.
A 2D finite element analysis for the numerical prediction of capacity curve of unreinforced mason... more A 2D finite element analysis for the numerical prediction of capacity curve of unreinforced masonry (URM) walls is conducted. The studied model is based on the fiber finite element approach. The emphasis of this paper will be on the errors obtained from fiber finite element analysis of URM structures under pushover analysis. The masonry material is modeled by different constitutive stress-strain model in compression and tension. OpenSees software is employed to analysis the URM walls. Comparison of numerical predictions with experimental data, it is shown that the fiber model employed in OpenSees cannot properly predict the behavior of URM walls with balance between accuracy and low computational efforts. Additionally, the finite element analyses results show appropriate predictions of some experimental data when the real tensile strength of masonry material is changed. Hence, from the viewpoint of this result, it is concluded that obtained results from fiber finite element analyses employed in OpenSees are unreliable because the exact behavior of masonry material is different from the adopted masonry material models used in modeling process.
External confinement of concrete by means of Carbon Fiber Reinforced Polymer (CFRP) can
significa... more External confinement of concrete by means of Carbon Fiber Reinforced Polymer (CFRP) can
significantly enhance its strength and ductility. One area where the use of CFRP has attracted
considerable interest is in the strengthening of Reactive Powder Concrete (RPC) columns. Proper design
of such hybrid columns, however, requires an accurate estimate of the performance enhancement. As a
result of CFRP confinement, the constitutive model of RPC in compression i.e. the stiffness, compressive
strength of RPC can be completely changed. This paper presents a finite element model capable
accurately to estimate the load-carrying capacity of RPC columns strengthened with CFRP under
compressive loads. Results from finite element model of CFRP-RPC are compared with RPC specimens,
and it shows enhancement in strength and ductility. Also the compression between the tests from previous
researches and finite element analysis shows good agreement.
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Papers by Muhammad Abbassi
significantly enhance its strength and ductility. One area where the use of CFRP has attracted
considerable interest is in the strengthening of Reactive Powder Concrete (RPC) columns. Proper design
of such hybrid columns, however, requires an accurate estimate of the performance enhancement. As a
result of CFRP confinement, the constitutive model of RPC in compression i.e. the stiffness, compressive
strength of RPC can be completely changed. This paper presents a finite element model capable
accurately to estimate the load-carrying capacity of RPC columns strengthened with CFRP under
compressive loads. Results from finite element model of CFRP-RPC are compared with RPC specimens,
and it shows enhancement in strength and ductility. Also the compression between the tests from previous
researches and finite element analysis shows good agreement.
significantly enhance its strength and ductility. One area where the use of CFRP has attracted
considerable interest is in the strengthening of Reactive Powder Concrete (RPC) columns. Proper design
of such hybrid columns, however, requires an accurate estimate of the performance enhancement. As a
result of CFRP confinement, the constitutive model of RPC in compression i.e. the stiffness, compressive
strength of RPC can be completely changed. This paper presents a finite element model capable
accurately to estimate the load-carrying capacity of RPC columns strengthened with CFRP under
compressive loads. Results from finite element model of CFRP-RPC are compared with RPC specimens,
and it shows enhancement in strength and ductility. Also the compression between the tests from previous
researches and finite element analysis shows good agreement.