Thesis Chapters by Khalaf Mohammad
An experimental study has been conducted to investigate the
behavior of reinforced concrete beams... more An experimental study has been conducted to investigate the
behavior of reinforced concrete beams strengthened with Carbon
Fiber-Reinforced Polymer (CFRP) under combined torsion and
bending moment effect. The beams were tested while subjected to
different torsion to moment ratio. A total of twenty beams were tested.
The beams were divided into four groups. Each group consisted of a
reference unstrengthened beam and four beams with different
strengthening schemes to identify the contribution of CFRP sheets on
the strengthened beams. Four strengthening schemes were proposed
and implemented. The effectiveness of proposed schemes was
evaluated.
Papers by Khalaf Mohammad
Nucleation and Atmospheric Aerosols, 2023
AL Rafdain Engineering Journal, Dec 28, 2007
This study presents a nonlinear analysis using the finite element method to predict the ultimate ... more This study presents a nonlinear analysis using the finite element method to predict the ultimate load and mode of failure for reinforced concrete deep beams with web openings. Materials nonlinearities due to cracking, plastic flow or crushing of concrete and yield conditions of the reinforcing steel are considered. The capabilities of the proposed model have been examined and demonstrated by analyzing five reinforced concrete deep beams with web openings.
8TH ENGINEERING AND 2ND INTERNATIONAL CONFERENCE FOR COLLEGE OF ENGINEERING – UNIVERSITY OF BAGHDAD: COEC8-2021 Proceedings
The native and metastable defects and their joint density of states in hydrogenated amorphous sil... more The native and metastable defects and their joint density of states in hydrogenated amorphous silicon obtained from the improved dual beam photoconductivity method
Journal of Physics: Conference Series, 2021
This study investigates the behavior of Built-up steel columns. The effect of shape, distribution... more This study investigates the behavior of Built-up steel columns. The effect of shape, distribution, and angle of inclination of the lacing have been studied, Finite element simulations are performed with ANSYS. A brick element with eight nodes and a shell element with eight nodes were adopted, After completing the study of the convergence between the laboratory analysis and the numerical analysis, the parametric study can begin by changing the dimensions of the lacing and the method of distributing the lacing in the structure of the manufactured steel column to make a comparison between the numerical analysis and the Experimental analysis for modeled models and determine the positive and negative points for each type of lacing used.
TJES Vol26 No.1 2019, 2019
This study investigates the effect of load eccentricity on the deep beams in terms of failure loa... more This study investigates the effect of load eccentricity on the deep beams in terms of failure load and failure mode by using ANSYS nonlinear finite element program. Three RC deep beams with shear span to depth ratios, varying from 0.91 to 1.67 are modeled. The comparison between experimental and numerical result under central load shows approximately fully match between them to ensure that the model was represented correctly. The model has been used to investigate the behavior of RC deep beams under eccentric loads with various heights of beams. Under eccentric load there was significant reduction in failure load. With increasing height of the beams the failure load increased gradually with incremental increases in height, also there is a clear reduction in failure load due to eccentricity. But when the eccentricity of the load on the beams reaches 50 mm all beams of different heights possess the same failure load and all of them are failed due to concrete crushing at the beam compr...
This study presents a nonlinear analysis using the finite element method to predict the ultimate ... more This study presents a nonlinear analysis using the finite element method to predict the ultimate load and mode of failure for reinforced concrete deep beams with web openings. Materials nonlinearities due to cracking, plastic flow or crushing of concrete and yield conditions of the reinforcing steel are considered. The capabilities of the proposed model have been examined and demonstrated by analyzing five reinforced concrete deep beams with web openings.
The current research studies the effect of high temperatures on the behavior of low-strength conc... more The current research studies the effect of high temperatures on the behavior of low-strength concrete after wrapping it with one layer of polymer carbon fiber(CFRP) for strengthening. Eighty-four specimens were examined, 42 wrapped with fiber CFRP sheets and 42 un-wrapped, where the study was conducted on cylindrical specimens (150 × 300 mm) that were exposed to different temperatures ranging from (100 to 600°C) for 1 and 2 hours as a period of exposure to heat. The behavior of low strength concrete represented by compressive strength, ultrasonic pulse velocity, dynamic modulus of elasticity, and weight loss are the focus of the practical part of the study. The results revealed, the compressive strength of the wrapped specimens increased by (35%) and (49%) when exposed to temperature (200°C) and for a period of one and two hours, respectively, compared to the unwrapped specimens and at the same degree. Also, the external strengthening with CFRP sheets acted as a protective layer for...
Many studies have been performed in recent years on strengthening RC (reinforced concrete) beams ... more Many studies have been performed in recent years on strengthening RC (reinforced concrete) beams in shear and bending using FRP (Fiber Reinforced Polymer) wraps and laminates. Torsional strengthening, however, has not attracted as much attention. The current study on the torsional strengthening of reinforced concrete beams was performed on reinforced concrete beams wrapped by CFRP (Carbon Fiber Reinforced Polymer). Several different configurations were used for the CFRP and the torque-twist angle paths of the beams were recorded to failure. The failure modes and the increase in the torsional strengths are presented in this paper.
Case Studies in Construction Materials
Journal of Physics: Conference Series
The aim of the study is to demonstrate the extent of the effect that occurs to continuous reinfor... more The aim of the study is to demonstrate the extent of the effect that occurs to continuous reinforced deep beams when performing a parametric study in terms of support settlement and different support conditions for dual span continuous deep beams (CDBs), in terms of failure load and failure mode, using the ANSYS 2020 nonlinear finite element program. As the parametric study relied on the laboratory study conducted by Yang et al. [8]. Six samples were taken from continuous reinforced concrete beams with two spans with the extension of the shear to the depth ratios (0.5, 1). This was done to ensure that the form was handled appropriately. The pre-owned model to research the behavior of deep RC girders under static support conditions with different beam heights. Whereas, it was observed that there is a marked variation in the value of the failure load under the influence of different support conditions and the support settlement that occurs in them. This inspection is characterized by real, conceivable results of support conditions and support settlement in presenting two span continuous reinforced concrete deep beams.
Tikrit Journal of Engineering Sciences, 2019
This study investigates the effect of the load eccentricity on the deep beams, in terms of failur... more This study investigates the effect of the load eccentricity on the deep beams, in terms of failure load and failure mode, using ANSYS nonlinear finite element program. Three RC deep beams with shear span to depth ratios, varying from 0.91 to 1.67 are modeled. A comparison between the experimental and numerical results, under central load, showed approximately full matching between them. This had been done in order to ensure that the model was represented properly. The used model for investigating the behavior of the RC deep beams under an eccentric load with various heights of beams showed that under eccentric load there was a significant reduction in the failure load. Increasing the beams height cause of an increase (gradually) of the failure load with the incremental increases of the height, also there was a clear reduction in the failure load due to eccentricity. For the load eccentricity value 50 mm all the beams of different heights possess the same failure load and all of them failed due to concrete crushing at the beam compression face.
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Thesis Chapters by Khalaf Mohammad
behavior of reinforced concrete beams strengthened with Carbon
Fiber-Reinforced Polymer (CFRP) under combined torsion and
bending moment effect. The beams were tested while subjected to
different torsion to moment ratio. A total of twenty beams were tested.
The beams were divided into four groups. Each group consisted of a
reference unstrengthened beam and four beams with different
strengthening schemes to identify the contribution of CFRP sheets on
the strengthened beams. Four strengthening schemes were proposed
and implemented. The effectiveness of proposed schemes was
evaluated.
Papers by Khalaf Mohammad
behavior of reinforced concrete beams strengthened with Carbon
Fiber-Reinforced Polymer (CFRP) under combined torsion and
bending moment effect. The beams were tested while subjected to
different torsion to moment ratio. A total of twenty beams were tested.
The beams were divided into four groups. Each group consisted of a
reference unstrengthened beam and four beams with different
strengthening schemes to identify the contribution of CFRP sheets on
the strengthened beams. Four strengthening schemes were proposed
and implemented. The effectiveness of proposed schemes was
evaluated.