Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Finite element

Comparison between Theoretical and Experimental Behavior of Shallow Foundation in Cohesive Soil

Baraa A. Al-Dawoodi; Mohaned Q. Waheed; Falah H. Rahil

Engineering and Technology Journal, 2021, Volume 39, Issue 12, Pages 1911-1918
DOI: 10.30684/etj.v39i12.2124

This paper discusses a finite element analysis of shallow footing subjected to axial loading rested on different types of cohesive soil by using a computer program called PLAXIS-3D (V.20) software. The behavior of cohesive soil is simulated using several constitutive models (Mohr-Coulomb model, Hardening soil model, and Hardening soil with small strain stiffness model in order to find the best match between theoretical and experimental results).Two cases are considered square and rectangle. Moreover, some parameters that affect the load settlement relation curve; such as internal friction angle and soil modulus elasticity were investigated. It was found that the simulation by the Hardening soil model with small strain stiffness gives better results in both cases of the square and rectangle (C=25) and square footing (C=70). It was also observed that increasing the foundation width led to increases in bearing capacity, however, there was an increase of bearing capacity to about (9.45 %) for an increase in footing width of (6.25), so it was about (17%) for (12.5). For square footing in stiff clayey soil, the bearing capacity of the soil increases to about (23%) when the range of the modules of elasticity of soil increases from (10000 to 30000KN/m2).

ANSYS-Based Structural Analysis Study of Elevated Spherical Tank Exposed to Earthquake

Mahmoud Saleh Al-Khafaji; Ahlam S. Mohammed; Muna A. Salman

Engineering and Technology Journal, 2021, Volume 39, Issue 6, Pages 870-883
DOI: 10.30684/etj.v39i6.460

Damage of elevated tanks during earthquakes can jeopardize the supply of drinking water and causes significant economic losses. Therefore, seismic analysis of tanks containing liquids requires special consideration. Knowledge of liquid hydrodynamic pressures developed during an earthquake is important for tank design. This paper aims to verify the dynamic reaction of structural systems of spherical elevated steel tanks containing water, and determine the natural frequencies that contribute to the physical response, as well as seismic analysis of the tank. A three dimensional Finite Element Model was developed to identify the main parameters involved in this response for three different fullness ratio (0.00%, 53.30% and 71.11%) using the ANSYS software. The model was implemented and validated based on the results of a previously conducted experimental study. Moreover, it was analyzed under the impact of the most severe earthquake that Iraq was exposed to in 2017 with a magnitude of 7.2 on the Richter scale. The results showed a very good agreement in natural frequency with a discrepancy (root mean square error) of 2% (0.05 Hz), 6.9% (0.15 Hz) and 9.5% (0.2 Hz) for the fullness ratio 0%, 53.3% and 71.11%, respectively In addition, the selected element type and the method of analysis are applicable. Moreover, results of displacement and stresses from earthquake analysis indicated that the spherical tank could lose stability in time 1.4 seconds of the proposed time for the worst part of the earthquake, when displacement records highest values in the direction of earthquake for the tank body at chosen points in the top, middle, and bottom of the tank body which were almost equally at all cases proposed in this study.

Nonlinear Finite Element Analysis of Fiber Reinforced Concrete Slabs

Saad A. Al-Taan; Ayad A. Abdul-Razzak

Engineering and Technology Journal, 2021, Volume 39, Issue 3A, Pages 426-439
DOI: 10.30684/etj.v39i3A.1641

This paper presents a study on the behavior of fiber reinforced concrete slabs using finite element analysis. A previously published finite element program is used for the nonlinear analysis by including the steel fiber concrete properties. Concrete is represented by degenerated quadratic thick shell element, which is the general shear deformable eight node serendipity element, and the thickness is divided into layers. An elastic perfectly plastic and strain hardening plasticity approach are used to model the compression behavior of concrete. The reinforcing bars were smeared within the concrete layers and assumed as either an elastic perfectly plastic material or as an elastic-plastic material with linear strain hardening. Cracks initiation is predicted using a tensile strength criterion. The tension stiffening effect of the steel fibers is simulated using a descending parabolic stress degradation function, which is based on the fracture energy concept. The effect of cracking in reducing the shear modulus and the compressive strength of concrete parallel to the crack direction is considered. The numerical results showed good agreement with published experimental results for two fibrous reinforced concrete slabs.

Nonlinear Finite Element Analysis of High Strength Fiber Reinforced Concrete Beams

Zinah A. Abdul Hussein

Engineering and Technology Journal, 2020, Volume 38, Issue 9, Pages 1293-1304
DOI: 10.30684/etj.v38i9A.1840

This research work presents a nonlinear finite element investigation on the behavior of high strength fiber reinforced concrete beams. This investigation is carried out in order to get a better understanding of their behavior throughout the entire loading history. The three- dimensional 20-node brick elements are used to model the concrete, while the reinforcing bars are modeled as axial members embedded within the concrete brick elements. The compressive behavior of concrete is simulated by an elastic-plastic work-hardening model followed by a perfectly plastic response, which terminate at the onset of crushing. In tension, a fixed smeared crack model has been used.

Numerical Study of Bond Stress-Slip Relationship in Large Scale Reactive Powder Concrete Beams

Eyad K. Sayhood; Sameh B. Tobeia; Ammar A. Ali

Engineering and Technology Journal, 2019, Volume 37, Issue 12A, Pages 496-505
DOI: 10.30684/etj.37.12A.1

As the reactive powder concrete (RPC) represents one of the ultra-high performance concrete types that recently used in public works and in the presence of several attempts that aims to examine the behavior of RPC, this work aims to theoretically study the bond stress between RPC and steel bars and the corresponding slip for large reactive powder concrete beams by using finite element models done by ANSYS 16.1 software. Where, these numerical models were verified through several comparisons between their results, and the experimental one from previous work, in which good agreement were achieved. The effects of several parameters on the bond stress were studied, the parameters include concrete compressive strength, and steel fibers content, bar diameter, length of the developed bar and concrete cover thickness.

Investigation of External and Internal Inversion for Aluminum Tube with Various Die Parameters Effect

Basim M. Fadhil; Ava Ali Kamal

Engineering and Technology Journal, 2019, Volume 37, Issue 7A, Pages 235-240
DOI: 10.30684/etj.37.7A.3

Finite element modeling has been conducted to investigate the
effect of die radius fillet, tube wall thickness, and friction coefficient on both
external and internal inversion for
aluminum tube. A 3D model was used
to build the contact pair for the a
luminum tube and the steel
. Due to the
axial symmetry, a 45
sector for the contact pair has been chosen. It has been
found that there is an important role for those parameters to govern the
inversion process and the mode of deformation beside the valu
e of the
applied force. No local buckling was seen in the external inversion in
contrast with internal inversion. A good correlation for current results with
experimental one that has been got by others.

Dynamic Finite Element Analysis of Sandy Soil-Pipe System Reinforced by Geogrid

N.H. Jajjawi

Engineering and Technology Journal, 2017, Volume 35, Issue 4, Pages 421-430

The stability of tunnels and other underground structures under the influence of dynamic load is one of the important issues that should be studied carefully. The objective of the present paper is to study the effect of the geogrid reinforcement in transfer of the dynamic load to the underground structure. The underground structure was simulated as a plastic pipe within the soil. The investigation focuses on the influence of parameters such as load amplitude, depth of geogrid layer and width of geogrid layer using the finite element method by QUAKE/W computer program for the analysis. It was concluded that when the geogrid reinforcement width equals (1B), the total stress on the crown of pipe decreases by about (17%) compared with unreinforced soil, but this percentage decreases to (10%) when the geogrid width equals to (2B). The percent vertical settlement on the pipe crown decreases by about (35%) when using reinforcement of width equals (2B) compared with test results unreinforced soil, while when the width equals (1B), the percent vertical settlement decreases to about (15%), this indicates that when the width of reinforced soil increases, the vertical settlement decreases.

Deformation Analysis of Road Embankment Foundation Soil Improved with Fiber Glass

Zainab Ahmed Alkaisi; Zena Hadi Alqaissi; Najwa Wasif Jassim

Engineering and Technology Journal, 2012, Volume 30, Issue 19, Pages 3341-3361

The main objective of this research is to evaluate the improvement of embankment
soil foundation soil using the fiber glass treatment. To accomplish the main objective,
laboratory tests, includes direct shear test and unconfined compression test are made to
evaluate the potential of acting the fiber glass as cementing agent in terms of strength
parameters (cohesion and angle of internal friction). The ANSYS program of version
(12.1) was employed for analyzing embankment foundation system. The results
showed that increasing the percent of fiber glass from (1 to 3%) reduce the vertical and
horizontal displacement about (75%) at 3%, and reduced the horizontal and vertical
strain about (75%, 85%) respectively at the same fiber glass content (3%). This means,
that the general role of adding the fiber glass works as a tender to soil mixture not as
fiber reinforcement. So it can be concluded that the fiber glass act as cementing agent
as shown in the obtained experimental results for strength parameters (cohesion and
angle of internal friction ) from the direct shear and the unconfined compression test
that carried out in this works.

Deflection Estimation of Un-Symmetric Isotropic Cam with Three Circular-Arc Contact Profiles

Louay Sabah Yousuf

Engineering and Technology Journal, 2012, Volume 30, Issue 6, Pages 1001-1016

In this paper the principal objectives is to design a suitable profile that produces minimum value of jerk and contact stress keeping the acceleration within a limit especially in high-speed machine. Many works in the experimental part are done on the synthesis of cam profile in accuracy and system flexibility on the output follower motion; but there is a lack in the analytical part. The analytical
formulation has been done with classical plate theory of un-symmetric cam with three circular-arc contact profiles using the equation of circular plate solution due to the distributed load comes from the perpendicular contact harmonic motion of the follower. The cam used in the paper can be found in cutting and metal forming tools, heavy duty of marine engine, and fast manufacturing equipment. The aim of
the present paper is to calculate the maximum deflection on cam boundaries varying with (r and θ) coordinates between beginning and ending of contact follower loadings. The results were classified into mathematical model and finite element using software ANSYS.

A Confined Flow over a Cylinder by the Finite Element and the Finite Difference Methods

Ahlam Sadir Mohammed

Engineering and Technology Journal, 2011, Volume 29, Issue 15, Pages 3108-3117

The Finite element and the finite difference methods were applied to a confined flow over a cylinder. The values of velocity potential (F), the stream function (Y) and the velocity distribution are calculated by using a computer programs achieved by the researcher. The results revealed that, convergence and divergence were achieved between the equipotential lines by two methods. The finite element method
has been shown to be a powerful tool. Small elements may be used in areas of rapid change and large elements may be used where variations are less severe. The boundary conditions are handled naturally by the finite element method in contrast to the finite difference method.
This study shows that the finite element method is the best technique for the solution of practical engineering problems like thermal and fluid flows (steady state or unsteady problems).

Nonlinear Behavior of Steel-Concrete Composite Beams Curved in Plane with CFRP Strips Bonding

Ahmed F. Kadhum

Engineering and Technology Journal, 2010, Volume 28, Issue 12, Pages 2308-2324

This paper deals with the behavior of structural steel-concrete composite beams
curved in plane. The analytical investigation included the use of three dimensional
nonlinear finite elements to model the performance of the composite beams
strengthened with CFRP strips by using (ANSYS 11.0) computer program. The
numerical results showed very good agreement with the experimental results reach
to 100% before the strengthening, while the increase in strength after the curved
strengthened with CFRP strips 32% for the curve beam with L/R equal to 0.05 and
48% for the curve beam with L/R equal to 0.10 and 53% for the curve beam with
L/R equal to 0.25.

Wedge Foundation in Expansive Soils

Mohammad A. Al-Neami; Farah S. Al-Jabary

Engineering and Technology Journal, 2009, Volume 27, Issue 13, Pages 2307-2318

The object of this study is to find a construction solution to the problem of expansive soils by suggesting of a new shape of the conventional footing which has a sharp edge, this footing is named a “wedge footing” which is considered as an alternative shape to the strip footing to dissipate the swelling pressure produced in the soil when inserting the footing in it. These soils have a tendency
to absorb water and expand causing high damage to the lightly loaded buildings and structures. The analysis carried out using finite element method to assess the behaviour of displacement of the wedge footing compared with strip footing which is considered as a basic problem. An equation is obtained from the results of the computer package of “STATISTICA” based on the results of finite element analysis related to the displacement of wedge shaped footing as a function of soil properties and footing with coefficient of regression of (R2= 98.9%).

Effect of Dual Reinforcement on Wear Resistance by Aluminum Compacts Reinforce by SiC, Al2O3

Mohammed Moanes Ezzaldean Ali; Hanan A. R. Akkar; A. K. M. AL-Shaikhli; Ali K. Shayyish; Muhsin J. Jweeg; Wisam Auday Hussain; Mohammed T. Hussein; Mohammad A. Al-Neami; Farah S. Al-Jabary; Jafar M. Hassan; Ali H. Tarrad; Mohammed N. Abdullah; Ahmed T. Mahdi; Eyad K. Sayhood; Husain M. Husain; Nidaa F. Hassan; Rehab F. Hassan; Akbas E. Ali; Assim H Yousif; Kassim K Abbas; Aqeel M Jary; Shakir A. Salih; Ali T. Jasim; Ammar A. Ali; Hosham Salim; JafarM. Daif; Ali H. Al Aboodi; Ammar S. Dawood; Sarmad A. Abbas; Salah Mahdi Saleh; Roshen T. Ahmed; Aseel B. Al-Zubaidi; Mohammed Y. Hassan; Majid A. Oleiwi; Shaimaa Mahmood Mahdy; Husain M. Husain; Mohammed J. Hamood; Shaima; a Tariq Sakin

Engineering and Technology Journal, 2009, Volume 27, Issue 13, Pages 423-429

The producing composite materials of dual reinforcement in which the matrix material is aluminum reinforced with two types of ceramic particles : which are Alumina (50μm


composite materials; wear test ; Al2O3; SiC: Al

Nonlinear Finite Element Analysis of Prestressed Concrete Tee Beams

May J. Hamoodi; Ihsan A. S. Al-Shaarbaf

Engineering and Technology Journal, 2009, Volume 27, Issue 2, Pages 275-287

A three-dimensional finite element computer program ( 3DMPCP ) has
been developed to investigate the behaviour of prestressed reinforced concrete
beams and to predict their ultimate loads. To verify the ability of this computer
program in predicting the correct behaviour of prestressed concrete beams, analysis
of a simply supported prestressed reinforced concrete tee beam was carried out.
The beam section is 1.12 m deep, 2.44 m flange width and it is designed for a span
of 32.3 m from support to support. The test load, 0.85(1.4 DL. + 1.7 LL.), was
applied to the beam and flexural cracks were observed at midspan. The finite
element analysis has indicated that numerical load-central deflection curve
obtained is in good agreement with the experimental one. The analysis also gives
the expectation for the ultimate load value. Distribution of concrete normal stress
throughout a cross section and along the beam, at different stages of loading , are