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Article
Study of Stress Intensity Factor in Corrugated Plate Using Extended Finite Element Method (XFEM)

Author: Rafil Mahmood Laftah
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2016 Volume: 34 Issue: 15 Part (A) Engineering Pages: 2982-2992
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

The presence of crack with different lengths and locations in structure of corrugated plate is studied. XFEM is along with enrichment function based on partition of unity is used for the calculation of stresses due to the presence of crack. Stress intensity factors (KI) and relations for shape factors (C) are calculated for the four most common crack orientations and loading conditions. Results showed that crack in the flange with load perpendicular to corrugation direction yields higher values of KI and C in addition to wider spread of stress concentration contours than the web. When loading becomes parallel to corrugation direction, the stress intensity factor and C factor become remarkably less due to the corrugation stiffness. Third mode KIII is appeared in the fourth case in addition to the presence of the first mode KI due to 45o inclination of the web and applied load direction

Keywords

SIF --- XFEM --- Corrugated plate --- ABAQUS


Article
Finite Element Modelling of Concrete Filled Double Skin Steel Tubular Columns under Cyclic Axial Compression Load
تمثيل سلوك الاعمدة الفولاذيه الانبوبية ثنائية القشرة المملؤة بالخرسانة تحت حمل شاقولي دوري بطريقة العناصر المحددة

Authors: Riyadh J. Aziz رياض جواد عزيز --- Laith Kh. Al-Hadithy ليث خالد الحديثي --- Shayma M. Resen شيماء محمد رسن
Journal: AL-NAHRAIN JOURNAL FOR ENGINEERING SCIENCES مجلة النهرين للعلوم الهندسية ISSN: 25219154 / eISSN 25219162 Year: 2017 Volume: 20 Issue: 2 Pages: 326-340
Publisher: Al-Nahrain University جامعة النهرين

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Abstract

CFDSST Concrete Filled Double-skinned steel tubular columns are composite columns consisting of two concentric circular steel tubes with concrete filler in between. Finite elements method is considered through the use of the computer program ABAQUS to model CFDSST columns numerically under cyclic axial compression. Damage plasticity model was considered to model the concrete while elastic-plastic model used to model the steel tubes. six CFDSST specimens and three ordinary Concrete Filled Steel Tubular (CFST) specimens were analyzed under static axial compression, while three CFDSST specimens were considered for analysis under cyclic axial compression. The numerical results were presented in terms of axial load axial strain displacement curves. It was found that the ultimate axial load carrying capacity calculated numerically in good agreement with that of the experimentally tested specimens. Also it was concluded that Damage plasticity model used for simulating the behavior of concrete and metal plasticity model used for simulating the behavior of steel produced accurate results as compared to the experimental results.

الاعمده الفولاذيه ثنائيه القشره المملؤة بالخرسانة CFDSST هي نوع من الاعمدة المركبة، حيث انها تتكون من أنبوبين حديدين خارجي وداخلي وفراغ بينهم يملئ بالخرسانة. في هذا البحث يتم دراسه سلوك الاعمده الفولاذيه ثنائيه القشره المملؤة بالخرسانة تحت الاحمال الدوريه العموديه بطريقه العناصر المحدده باستخدام البرنامج ABAQUS , حيث تم استخدام موديل التضرر اللدن للخرسانة والموديل المرن- اللدن للانابيب الفولاذيه, سته نماذجCFDSST) وثلاثه نماذج (CFST) تم تحليلها تحت تاثير الحمل الشاقولي الساكن وثلاثه نماذج تحت تاثير الحمل الشاقولي الدوري. عرضت النتائج التحليليه من خلال علاقات الحمل والازاحة العمودية. وجد من خلال هذا البحث ان النتائج العمليه موافقه مع نتائج البحث وايضا ان الموديل المستخدم لتمثيل الاعمده تحت تاثير الحمل العمودي الدوري يعطي نتائج جيده من خلال مقارنتها مع النتائج العمليه.


Article
STRUCTURAL STUDY OF FRP COMPOSITE PILE UNDER AXIAL COMPRESSION LOAD USING FINITE ELEMENT METHOD
دراسة أنشائية لركيزة ألياف بوليميرية مسلحة مركبة تحت حمل ضغط محوري بإستخدام طريقة العناصر المحددة

Author: Abbas Adday Al -Zayadi
Journal: Journal of Engineering and Sustainable Development مجلة الهندسة والتنمية المستدامة ISSN: 25200917 Year: 2017 Volume: 21 Issue: 3 Pages: 174-188
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

FRP-concrete- steel is a new hybrid composite structural member combines the privileges confined compressive strength of concrete and the ductility of steel to produce a lighter in weight member with considerable carrying capacity. In this research the FRP hybrid member was utilized as a pile which is a special case of FRP concrete filled pile with a hollow steel tube inside. F.E modeling were carried out for this new hybrid pile using the computer program ABAQUS, in which confined concrete model was included through the Concrete Damage Plasticity model. Verification of the model was implemented through the simulation of experimentally tested specimens, good agreement were achieved between experimental and F.E results. The F.E model was considered in studying the effects of FRP tube thickness, steel tube thickness, Hollowness ratio and stiffness of concrete. The results were presented in terms of axial load-axial strain curves. It has been found that the axial strength ratio increased as the stiffness of concrete, steel, and FRP increased while it decreased with the increase of hollowness ratio.

ان استخدام الالياف البوليمرية المسلحة مع الخرسانة مع والحديد كعنصر انشائي هجين مركب يجمع خاصية مقاومة الانضغاط العالية للخرسانة المحصورة مع ليونة الحديد للحصول على عنصر انشائي اخف وزنا وذو قابلية تحمل معتبرة. في هذا البحث تم استخدام هذا العنصر الانشائي كركيزة حيث يعتبر حالة خاصة من ركيزة الالياف البوليمرية المسحلة المملؤة بالخرسانة مع انبوب حديد مجوف في داخلها. تم استخدام طريقة العناصر المحددة لتمثيل هذاالنوع من الركائز من خلال برنامج الحاسوب (ABAQUS) من خلال تمثيل الخرسانة المحصورة باستخدام نموذج الخرسانة المتضررة اللدنة (CDP) وللتأكد من هذا النموذج تم مقارنته مع نتائج فحوصات عملية ، حيث كانت هناك مطابقة جيدة بين نتائج طريقة العناصر المحددة ونتائج الفحوصات العملية . استخدم هذا النموج ومن خلال الطريقة المذكورة لدراسة تاثيربعض العناصر على سلوك الركيزة مثل : سمك طبقة الالياف البوليمرية المسلحة و سمك الانبوب الحديد و مقاومة الخرسانة للانضغاط بالاضافة الى نسبة الفراغ. تم عرض نتائج البحث على شكل علاقات بين الحمل المحوري مع الانفعال المحوري حيث لوحظ ان نسبة المقاومة تزداد بزيادة صلابة كل من الخرسانة والحديد والالياف البوليمرية المسلحة في حين انها تقل بزيادة نسبة الفراغ


Article
Numerical Investigation on the Influence of Web Opening on the Structural Behaviour of RC Deep Beams

Author: Abdulnasser Mohammed Abbas
Journal: Al-Qadisiyah Journal for Engineering Sciences مجلة القادسية للعلوم الهندسية ISSN: 19984456 Year: 2019 Volume: 12 Issue: 3 Pages: 178-183
Publisher: Al-Qadisiyah University جامعة القادسية

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Abstract

Nowadays, the deep beams become utilized more in a considerable number of structures. It is necessary sometimes to introduce a hole within the web of the beam as a pipe or a duct for many purposes such as water supply, sewage, electricity, air conditioning, and computer network. In this study, a deep beam sample taken from a past experimental study is numerically analysed using a three-dimensional finite element model. ABAQUS tools are used to simulate the whole FE models. The dimensions of the considered deep beam are 820x400x180 mm, with two openings of a diameter 90 mm located at 200 mm from both of the ends. The proposed model and the experimental work have reasonably agreed with a difference of 2 % in mid-span deflection. Furthermore, special reinforcements of 12 mm bar diameter are offered to the original FE model around the holes in two types, Z-shape and circular, to improve the structural behaviour of the deep beam and to minimize the crack concentrations in these zones. The gained results show that the additional reinforcement minimizes the mid-span deflection of the deep beam. As compared with the original proposed FE model, the Z-shape decreases the deflection by 44.9 % while the lowering in the defection of the circular shape is 9.4 %. Moreover, the concentration of stresses and cracks that gained from using the Z-shape reinforcement model found to be lower than those induced in the circular reinforcement model.


Article
Effect of Swelling Soil on Load Carrying Capacity of a Single Pile
تأثير الترب اللأنتفاخيه على قابليه تحمل الركيزه

Authors: Ala Nasir Aljorany --- Fatema Safaa Noori
Journal: Journal of Engineering مجلة الهندسة ISSN: 17264073 25203339 Year: 2013 Volume: 19 Issue: 7 Pages: 896-905
Publisher: Baghdad University جامعة بغداد

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Abstract

Expansive soils are recognized by their swelling potential upon wetting due to the existence of some clay minerals such as montmorillonite. An effective solution was found to avoid the danger of such soils by using piles. A single pile embedded in an elasto-plastic expansive soil has been analyzed by using one of the available software which is ABAQUS to investigate the effect of applied loads on pile’s top and investigate the effect of swelling soils on load carrying capacity of the pile. The result shows that as the pile is axially loaded at its top, the axial force along the pile gradually changes from (tension) to (compression) and the pile tends to move downward. The applied load needed to initiate pile’s settlement depends on pile’s embedment depth and the depth of active zone. The ultimate carrying capacity of a single pile for no swelling conditions is greater than that of with swelling conditions.

تعرف الترب الانتفاخيه بخاصيه التغير الحجمي عند تعرضها للماء حيث يزداد حجمها نتيجة لوجود بعض المعادن مثل Montmorolonite. حيث تم ايجاد حل لغرص تفادي المشاكل الناتجه من هذه الترب وذلك بأستخدام الركائز. ولغرض معرفة مقدار تحمل الركائز ومدى تأثرها بالأحمال المسلطه عليها تم تحليل ركيزة مفردة ممتدة في تربة إنتفاخية (Elasto-plastic soils) بأستخدام طريقة العناصر المحددة Finite Elements Method وتم ذلك بأستخدام برنامج ABAQUS. و أظهرت النتائج عند تحميل الركيزه فأن القوى المحوريه تتغير تدريجيا من قوى شد لى قوى ضغط على طول الركيزه والقوه اللازمه لبدأ نزول الركيزه يعتمد على طول الركيزه وعمق الطبقه الانتفاخيه. أما بالنسبه لمقدار تحمل ركيزه مفرده في تربه اعتياديه يكون اكبر من مقدار تحمل ركيزه مفرده ممتده في تربه انتفاخيه.


Article
Prediction of the Thermal Conductivity of concrete using ABAQUS model
تقدير معامل الموصلية الحرارية للخرسانة باستخدام برنامج ABAQUS

Author: Tumadhir Merawi Borhan
Journal: Al-Qadisiyah Journal for Engineering Sciences مجلة القادسية للعلوم الهندسية ISSN: 19984456 Year: 2014 Volume: 7 Issue: 1 Pages: 127-136
Publisher: Al-Qadisiyah University جامعة القادسية

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Abstract

ABSTRACTAn attempt to determine an easy and accurate method to predict the thermal conductivity of concrete is presented in this paper. The new method is based on the heat transfer test results and the finite element software package ABAQUS. The boundary condition for this model was the temperature profile of the exposed side of the specimen which was taken from the heat transfer tests. The values of the thermal conductivity that give the closed agreement curve for the unexposed surface temperature profile were recorded for a different temperature levels. This method can be adopted to compare the value of the thermal conductivity of any type of concrete with other concrete as an easy and fast alternative method to the standard test methods

الخلاصةيقدم هذا البحث محاولة جديدة لايجاد طريقة سهلة ودقيقة لتقدير معامل الموصلية الحرارية للخرسانة . تستند هذه الطريقة على نتائج اختبار انتقال الحرارة وعلى طريقة التحليل بالعناصر المحددة باستخدام البرنامج ABAQUS. ان المحددات لطريقة العناصر المحددة هي التغير الحراري مع الزمن للسطح المعرض للحرارة بصورة مباشرة والسطح الغير معرض للحرارة. سجلت قيم الموصلية الحرارية التي تعطي أفضل توافق لمنحنى التغير بدرجة الحرارة للسطح الغير معرض للحرارة بصورة مباشرة. اظهرت النتائج انه بالامكان اعتماد هذه الطريقة للحصول على قيمة تقريبية لمعامل الموصلية الحرارية بصورة سريعة ودقة لاي نوع من انواع الخرسانة والاستفادة منها للمقارنة مع انواع اخرى من الخرسانة في حالة تعذر اجراء الطريقة القياسية للفحص


Article
FINITE ELEMENT MODELING OF RUTTING FOR FLEXIBLE PAVEMENT

Authors: Zainab Ahmed Alkaissi --- Yasir Mawla Al-Badran
Journal: Journal of Engineering and Sustainable Development مجلة الهندسة والتنمية المستدامة ISSN: 25200917 Year: 2018 Volume: 22 Issue: 3 Pages: 1-13
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

The aim of this research is studying the effect of base and subgrade layer local materials properties on the rutting damage of flexible pavement due to repeated traffic loading. The most roads in Baghdad city present severe rutting damage due to absence of quality control in the construction of granular unbounded pavement layer. Furthermore many trucks with overweight using the roads and high temperature in summer produced distresses and deterioration of flexible pavement. Flexible pavement analyses are performed using finite element method; a 3-D dimensional finite element model using ABAQUS (ver. 6.12-1) computer program are developed. The results obtained for base layer show reduction in rutting damage by about (58%) while subgrade layer provided damage reduction only (10%). Also the critical value for vertical compressive stresses is (480 kPa) below the wheel loading area which is about (70.9%) of the applied tire pressure and then decreased gradually with depth to about (118 kPa) approximately (17%) of the applied tire pressure within the base layer and remains almost constant with depth through the subgrade layer. And for horizontal stresses a high value was observed on surface of flexible pavement under the path of wheel load rather than the compressive stresses then decreased laterally with horizontal distance.The local untreated base material experience critical rut depth of (8 mm) at 1000 number of repetitions and for treatment base materials the number of load repetitions to cause damage rutting increased (10) times to about 10000 number of load repetitions.The treated base materials decreased the rutting damage factor. This implicates the main role of granular base layer in pavement system support to minimize the rutting damage.


Article
NON-LINEAR ANALYSIS TO IMPROVE PUNCHING SHEAR STRENGTH IN FLAT SLAB USING Z-SHAPE SHEAR REINFORCEMENT

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Abstract

Currently, flat slabs become one of the widely used structures due to its architectural benefits such as uncomplicated formwork, flexibility and minimum construction time. However, these structures are relatively weak to resist the punching shear due to a considerable lowering in stiffness induced from the development of cracks that resulting from axial and seismic loads. Moreover, the punching failure is considered a brittle failure caused by the transferring of unbalanced moments and shear forces between the structural members. Unfortunately, this may cause a catastrophic collapse, especially in the region of the slab-column. Therefore, many experimental and theoretical studies were done to improve the punching strength of the flat slab. In the current work; a finite element three-dimensional non-linear analysis has simulated by ABAQUS tool to investigate the structural behaviour of flat slab. Two specimens have considered, the first is a flat slab reinforced by ordinary steel reinforcement. While in the second one, a Z-shape shear rebar improvement has been added to the slab-column connection. The proposed model has reflected a reasonable enhancement to the flat slab. The analysis considers different parameters such as punching shear forces, deformations, and stresses of Von-Mises. The outcomes indicate that punching shear strength is increased by approximately 11.1%, and the deflections are decreased by 77.3% when the Z-shape reinforcement is used. In the meantime, stress concentrations were reduced and move from the slab-column connection.


Article
Numerical Study on The Structural Behavior of RC Beams after Exposure to Elevated Temperature

Authors: Sajida Kadhem Al-Jasmi --- Haitham Al-Thairy
Journal: Al-Qadisiyah Journal for Engineering Sciences مجلة القادسية للعلوم الهندسية ISSN: 19984456 Year: 2019 Volume: 12 Issue: 4 Pages: 246-253
Publisher: Al-Qadisiyah University جامعة القادسية

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Abstract

This paper presents a numerical simulation of the structural response of reinforced concrete (RC) beams under elevated temperature using the commercial finite element package ABAQUS. A numerical model is firstly suggested by selecting the appropriate geometrical and material properties of the RC beam model at elevated temperature. Thereafter, the suggested numerical model was validated against the experimental tests conducted in this study. The validation results in terms of temperatures- time histories; load-mid span deflection of the RC beams have confirmed the accuracy of the suggested numerical model. The validated numerical model was implemented in conducting a parametric study to investigate the effects of two important parameters on the behavior and failure of RC beams under elevated temperature. These parameters are the effect of the high ranges of elevated temperatures; and the effect of heating rate. The parametric study results have revealed that the failure load and the ductility of RC beams under elevated temperature are not considerably influenced by changing the heating rate. It has also been concluded that the ultimate load capacities of RC beams have considerably decreased by 55.49%, 74.72%, and 81.31% comparing with the control RC beam when they exposed to temperature values of 600 ºC, 700 ºC, and 800ºC respectively. These conclusions may be used in the design of RC beams subjected to fire induced temperature.


Article
Non Linear Finite Element Modeling of Reinforced Concrete Flat Plate Slabs with openings
التحليل اللاخطى للعناصز المحددة لنمذجة البلاطات الخرسانية المسلحة المسطحة والحاوية على الفتحات

Author: Serwan Kh.Rafiq سيروان خورشيد رفيق
Journal: Sulaimania Journal for Engineering Sciences مجلة السليمانية للعلوم الهندسية ISSN: 24101699/24156655 Year: 2017 Volume: 4 Issue: 4 Pages: 28-40
Publisher: university of Sulaimania جامعة السليمانية

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Abstract

In this study, a model using ABAQUS/ EXPLICIT program to predict punching shear resistance of reinforced concrete flat plates was proposed with opening in different situation subjected to vertical loading. A three dimensional non-linear finite element program (ABAQUS/EXPLICIT) based on Eight-Nodes hexahedral element damage-plasticity was utilized for modeling concrete with opening, in this investigation. Reinforcing bars were represented by one dimensional element embedded in the solid elements and for both tension and compression linear elastic-plastic behavior is assumed.Nonlinear analysis is used and the result of finite element shows good agreement with the experimental results.

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