This study presents results from a theoretical-experimental program of beams partially pre-stressed made with continuous recycled PET strip-reinforced concrete (plain concrete strength of 20 MPa). These studies mainly attempted to determine the stripinfluence in altering the flexural strength at first and final crack. Also the load-deflection, ductility, energy absorption capacity of the beams are observed and the studies can be used in predicting the flexural behavior of longitudinally reinforced concrete. The model theory assumes that concrete has a tensile load capacity different from zero, characterized by a uniaxial tensile stress-strain diagram. The need for non-linear geometric and the material models imply the use of numerical methods such as the finite element method; so that, a finite element analysis of reinforced concrete beam with strips-reinforced plastic is performed. The obtained results were compared with computer analysis and experimental data to corroborate the validity of the suggested method, showing that the theory also predicts correctly the post-cracking creep deformation.
DESIGN AND ANALYSIS OF BRIDGE WITH TWO ENDS FIXED ON VERTICAL WALL USING FIN...IAEME Publication
The Finite element analyses are conducted to model the tensile capacity of steel fiber-reinforced concrete (SFRC). For this purpose bridge with two ends fixed one specimen are casted and tested under direct and uni-axial tension. Two types of aggregates (brick and stone) are used to cast the SFRC and plain concrete. The fiber volume ratio is maintained 1.5 %. Total 8 numbers of dog-bone specimens are made and tested in a 1000-kN capacity digital universal testing machine (UTM). The strain data are gathered employing digital image correlation technique from high-definition images and high-speed video clips. Then, the strain data are synthesized with the load data obtained from the load cell of the UTM.
Finite Element Modeling of a Multi-Storeyed Retrofitted Reinforced Concrete F...IOSR Journals
In the present study, the non-linear response of RC frame using FE modeling under the incremental
loading has been carried out in the first phase of analysis to study the response and load-carrying capacity of a
four storeyed RC frame using non-linear finite element analysis. In the second phase of study an analysis model
for retrofitted RC frame using finite element method using software ATENA is presented. The results obtained
from FE analysis in both cases are compared with the experimental data for four storeyed RC frame tested by
BARC at CPRI. The results from finite element analysis were calculated at the same location as used in
experimental test. The accuracy of the finite element model is assessed by the comparison with experimental
results which are to be in good agreement. The base shear/ displacement curves from finite element analysis
agree well with the experimental results in linear range. The maximum difference in base shear is observed to
be 7.9%
DESIGN AND ANALYSIS OF BRIDGE WITH TWO ENDS FIXED ON VERTICAL WALL USING FIN...IAEME Publication
The Finite element analyses are conducted to model the tensile capacity of steel fiber-reinforced concrete (SFRC). For this purpose bridge with two ends fixed one specimen are casted and tested under direct and uni-axial tension. Two types of aggregates (brick and stone) are used to cast the SFRC and plain concrete. The fiber volume ratio is maintained 1.5 %. Total 8 numbers of dog-bone specimens are made and tested in a 1000-kN capacity digital universal testing machine (UTM). The strain data are gathered employing digital image correlation technique from high-definition images and high-speed video clips. Then, the strain data are synthesized with the load data obtained from the load cell of the UTM.
Finite Element Modeling of a Multi-Storeyed Retrofitted Reinforced Concrete F...IOSR Journals
In the present study, the non-linear response of RC frame using FE modeling under the incremental
loading has been carried out in the first phase of analysis to study the response and load-carrying capacity of a
four storeyed RC frame using non-linear finite element analysis. In the second phase of study an analysis model
for retrofitted RC frame using finite element method using software ATENA is presented. The results obtained
from FE analysis in both cases are compared with the experimental data for four storeyed RC frame tested by
BARC at CPRI. The results from finite element analysis were calculated at the same location as used in
experimental test. The accuracy of the finite element model is assessed by the comparison with experimental
results which are to be in good agreement. The base shear/ displacement curves from finite element analysis
agree well with the experimental results in linear range. The maximum difference in base shear is observed to
be 7.9%
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Composite Behaviour of Unbraced Multi-Storey Reinforced Concrete Infilled Fra...IJERA Editor
A comparative assessment on analytical outputs of the composite behavior of multi-storey reinforced concrete infilled frames using the macro models of the one-strut configuration and the finite element micro model is presented. The effect of openings in the infill was given particular attention in multi-storey building frames. The analysis demonstrated the simplicity of modified one-strut model, compared to the more complex multi strut and FE models while at the same time yielding highly accurate results. The introduction of the shear stress reduction factor clearly enhanced the efficiency of the one-strut model to reproduce the shear strength, lateral stiffness and seismic demand of infilled frames with openings.
There are many parameters of concrete that
influence its strength gaining characteristics. This study is
an attempt to use the early compressive strength test result to
estimate compressive strength at different ages. Potential
utilization of the early day compressive strength result to
predict characteristic strength of normal weight concrete has
been investigated. A simple mathematical model capable of
predicting the compressive strength of concrete at any age is
proposed for both stone and local aggregate concrete. The
basic model consists of a rational polynomial equation having
only two coefficients. This study also proposes a simple reliable
relationship between the coefficient p (strength at infinite
time) with the strength values of concrete of a particular day.
This relation greatly simplifies the concrete strength
prediction model. The developed model is validated for
commonly used stone aggregate concrete and also for local
(brick) aggregate concrete. Data used in this study are collected
from some previous studies and recent experimental works.
The analysis carried with the model using different data
exhibit reliable prediction of concrete strength at different
ages (7, 14, 28 days etc.) with excellent efficiency.
Investigation of the Behaviour for Reinforced Concrete Beam Using Non Linear...IJMER
This study presents theoretical investigation that reinforced concrete and composite
construction might be suitably combined to give a new structural material : composite reinforced
concrete. To study theoretically the composite beam, non-linear three-dimensional finite elements
have been used to analyze the tested beam.
The 8-node brick elements in (ANSYS) are used to represent the concrete, the steel bars are modelled
as discrete axial members connected with concrete elements at shared nodes assuming perfect bond
between the concrete and the steel. The results obtained by finite element solution showed good
agreement with experimental results.
The main objective of the present investigation is to carry out a nonlinear analysis of reinforced
concrete beams resting on elastic foundation. Material nonlinearities due to cracking of concrete,
plastic flow, crushing of concrete and yielding of reinforcement are considered. Foundation
representation is assumed linear using Winkler model.
The reinforced concrete beam is modelled by using three dimensional finite elements with steel bars
as smeared layers. The examples have been chosen in order to demonstrate the applicability of the
modified computer program (Dynamic Analysis of Reinforced Concrete Beams on Elastic
Foundations DARCEF ) by comparing the predicted behaviour with that from other experimental and
analytical observations. The program modified in the present research work is capable of simulating
the behaviour of reinforced concrete beams resting of Winkler foundation and subjected to different
types of loading. The program solutions obtained for different reinforced concrete beams resting on
elastic foundations are in good agreement with the available results. Maximum percentage difference
in deflection is 15 %
LABORATORY MODEL TESTS TO EFFECT OF DENSITY TO FILL MATERIAL ON THE PERFORMAN...IAEME Publication
The effective functioning of reinforced earth structures is very much dependent on the quality of materials and construction. Many times, due to poor quality of the materials used and poor quality control measures exercised, the density of the reinforced soil fill is not up to the design requirements, leading to underperformance or distress of the reinforced soil walls. Therefore, it becomes necessary to evaluate the level of underperformance vis-à-vis that of relative compaction. In view of this, in the present study, a series of laboratory experiments were carried out on a model soil wall of 300 mm high with vertical face, prepared at different density states of 95%, 80% and 70% of MDD of IS HCT. The wall was subjected to monotonic load applied through a model square footing of size (B) equal to 50 mm on the surface at an offset distance of 1(B). Similar tests were carried out on the soil wall reinforced with a Woven Geotextile in wrap around form; to study the effect of density on the performance of reinforced soil wall. The results indicated proportionality between relative compaction level and performance of soil wall without and with reinforcement.
Experimental Determination of Fracture Energy by RILEM Methodtheijes
This paper deals with investigation of fracture energy (GF) of concrete. The study involves experimental determination of fracture energy (GF) by testing three point bend concrete beams of same size but varying notch to depth ratios. RILEM fracture energy (GF) and Stress Intensity factor values is determined
Finite Elements Modeling and Analysis of Double Skin Composite PlatesIOSR Journals
Abstract: Double skin composite (DSC) is a form of “steel/concrete/steel” sandwich structure; the steel plates
are connected to a sandwiched concrete core with welded stud shear connectors. In the present paper, a finite
element model for Double Skin Composite (DSC) panels subjected to quasi-static loading is developed. A series
of quasi-static finite elements models are used to analyze deformation and energy absorption capacity of such
system, when perforated by rigid penetrator with conical nose shape. Pilot test model is used to investigate the
failure pattern in the composite panel. The obtained results are compared to the experimental results; good
agreements are obtained between finite element and previous experimental results. Results show that such
elements have great ability of absorbing energy when subjected to perforation due to ductility of lower plate
skin and vertical stiffness of lower shear studs.
Dynamic Analysis of Double-Skin Composite Steel PlatesIOSR Journals
Double Skin Composite (DSC) plates are subjected to impact required to cause complete perforation and the accompanied failure modes are investigated. The amount of energy absorbed is calculated by capturing the residual velocity of penetrator after perforating the lower plate. The difference in initial kinetic energy and residual kinetic energy is the amount of energy absorbed by the panel. In the present paper a non-linear three-dimensional finite element models for Double Skin Composite panels subjected to dynamic loading is introduced. Pilot model is used to investigate the failure pattern in the composite panel when subjected to impact loads by rigid steel penetrator, while the other models are used to analyze the energy absorption capacity of such system when perforated. Results showed that such elements have good ability of absorbing energy when subjected to perforation, due to ductility of lower plate skin and vertical stiffness of lower shear studs.
Evaluation of Euclidean and Manhanttan Metrics In Content Based Image Retriev...IJERA Editor
Content-based Image Retrieval is all about generating signatures of images in database and comparing the signature of the query image with these stored signatures. Color histogram can be used as signature of an image and used to compare two images based on certain distance metric. Distance metrics Manhattan distance (L1 norm) and Euclidean distance (L2 norm) are used to determine similarities between a pair of images. In this paper, Corel database is used to evaluate the performance of Manhattan and Euclidean distance metrics. The experimental results showed that Manhattan showed better precision rate than Euclidean distance metric. The evaluation is made using Content based image retrieval application developed using color moments of the Hue, Saturation and Value(HSV) of the image and Gabor descriptors are adopted as texture features.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Composite Behaviour of Unbraced Multi-Storey Reinforced Concrete Infilled Fra...IJERA Editor
A comparative assessment on analytical outputs of the composite behavior of multi-storey reinforced concrete infilled frames using the macro models of the one-strut configuration and the finite element micro model is presented. The effect of openings in the infill was given particular attention in multi-storey building frames. The analysis demonstrated the simplicity of modified one-strut model, compared to the more complex multi strut and FE models while at the same time yielding highly accurate results. The introduction of the shear stress reduction factor clearly enhanced the efficiency of the one-strut model to reproduce the shear strength, lateral stiffness and seismic demand of infilled frames with openings.
There are many parameters of concrete that
influence its strength gaining characteristics. This study is
an attempt to use the early compressive strength test result to
estimate compressive strength at different ages. Potential
utilization of the early day compressive strength result to
predict characteristic strength of normal weight concrete has
been investigated. A simple mathematical model capable of
predicting the compressive strength of concrete at any age is
proposed for both stone and local aggregate concrete. The
basic model consists of a rational polynomial equation having
only two coefficients. This study also proposes a simple reliable
relationship between the coefficient p (strength at infinite
time) with the strength values of concrete of a particular day.
This relation greatly simplifies the concrete strength
prediction model. The developed model is validated for
commonly used stone aggregate concrete and also for local
(brick) aggregate concrete. Data used in this study are collected
from some previous studies and recent experimental works.
The analysis carried with the model using different data
exhibit reliable prediction of concrete strength at different
ages (7, 14, 28 days etc.) with excellent efficiency.
Investigation of the Behaviour for Reinforced Concrete Beam Using Non Linear...IJMER
This study presents theoretical investigation that reinforced concrete and composite
construction might be suitably combined to give a new structural material : composite reinforced
concrete. To study theoretically the composite beam, non-linear three-dimensional finite elements
have been used to analyze the tested beam.
The 8-node brick elements in (ANSYS) are used to represent the concrete, the steel bars are modelled
as discrete axial members connected with concrete elements at shared nodes assuming perfect bond
between the concrete and the steel. The results obtained by finite element solution showed good
agreement with experimental results.
The main objective of the present investigation is to carry out a nonlinear analysis of reinforced
concrete beams resting on elastic foundation. Material nonlinearities due to cracking of concrete,
plastic flow, crushing of concrete and yielding of reinforcement are considered. Foundation
representation is assumed linear using Winkler model.
The reinforced concrete beam is modelled by using three dimensional finite elements with steel bars
as smeared layers. The examples have been chosen in order to demonstrate the applicability of the
modified computer program (Dynamic Analysis of Reinforced Concrete Beams on Elastic
Foundations DARCEF ) by comparing the predicted behaviour with that from other experimental and
analytical observations. The program modified in the present research work is capable of simulating
the behaviour of reinforced concrete beams resting of Winkler foundation and subjected to different
types of loading. The program solutions obtained for different reinforced concrete beams resting on
elastic foundations are in good agreement with the available results. Maximum percentage difference
in deflection is 15 %
LABORATORY MODEL TESTS TO EFFECT OF DENSITY TO FILL MATERIAL ON THE PERFORMAN...IAEME Publication
The effective functioning of reinforced earth structures is very much dependent on the quality of materials and construction. Many times, due to poor quality of the materials used and poor quality control measures exercised, the density of the reinforced soil fill is not up to the design requirements, leading to underperformance or distress of the reinforced soil walls. Therefore, it becomes necessary to evaluate the level of underperformance vis-à-vis that of relative compaction. In view of this, in the present study, a series of laboratory experiments were carried out on a model soil wall of 300 mm high with vertical face, prepared at different density states of 95%, 80% and 70% of MDD of IS HCT. The wall was subjected to monotonic load applied through a model square footing of size (B) equal to 50 mm on the surface at an offset distance of 1(B). Similar tests were carried out on the soil wall reinforced with a Woven Geotextile in wrap around form; to study the effect of density on the performance of reinforced soil wall. The results indicated proportionality between relative compaction level and performance of soil wall without and with reinforcement.
Experimental Determination of Fracture Energy by RILEM Methodtheijes
This paper deals with investigation of fracture energy (GF) of concrete. The study involves experimental determination of fracture energy (GF) by testing three point bend concrete beams of same size but varying notch to depth ratios. RILEM fracture energy (GF) and Stress Intensity factor values is determined
Finite Elements Modeling and Analysis of Double Skin Composite PlatesIOSR Journals
Abstract: Double skin composite (DSC) is a form of “steel/concrete/steel” sandwich structure; the steel plates
are connected to a sandwiched concrete core with welded stud shear connectors. In the present paper, a finite
element model for Double Skin Composite (DSC) panels subjected to quasi-static loading is developed. A series
of quasi-static finite elements models are used to analyze deformation and energy absorption capacity of such
system, when perforated by rigid penetrator with conical nose shape. Pilot test model is used to investigate the
failure pattern in the composite panel. The obtained results are compared to the experimental results; good
agreements are obtained between finite element and previous experimental results. Results show that such
elements have great ability of absorbing energy when subjected to perforation due to ductility of lower plate
skin and vertical stiffness of lower shear studs.
Dynamic Analysis of Double-Skin Composite Steel PlatesIOSR Journals
Double Skin Composite (DSC) plates are subjected to impact required to cause complete perforation and the accompanied failure modes are investigated. The amount of energy absorbed is calculated by capturing the residual velocity of penetrator after perforating the lower plate. The difference in initial kinetic energy and residual kinetic energy is the amount of energy absorbed by the panel. In the present paper a non-linear three-dimensional finite element models for Double Skin Composite panels subjected to dynamic loading is introduced. Pilot model is used to investigate the failure pattern in the composite panel when subjected to impact loads by rigid steel penetrator, while the other models are used to analyze the energy absorption capacity of such system when perforated. Results showed that such elements have good ability of absorbing energy when subjected to perforation, due to ductility of lower plate skin and vertical stiffness of lower shear studs.
Evaluation of Euclidean and Manhanttan Metrics In Content Based Image Retriev...IJERA Editor
Content-based Image Retrieval is all about generating signatures of images in database and comparing the signature of the query image with these stored signatures. Color histogram can be used as signature of an image and used to compare two images based on certain distance metric. Distance metrics Manhattan distance (L1 norm) and Euclidean distance (L2 norm) are used to determine similarities between a pair of images. In this paper, Corel database is used to evaluate the performance of Manhattan and Euclidean distance metrics. The experimental results showed that Manhattan showed better precision rate than Euclidean distance metric. The evaluation is made using Content based image retrieval application developed using color moments of the Hue, Saturation and Value(HSV) of the image and Gabor descriptors are adopted as texture features.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Effect of Cooking on the Polyunsaturated Fatty Acid and Antioxidant Propertie...IJERA Editor
The effect of cooking method on the polyunsaturated fatty acid and antioxidant properties of small indigenous freshwater fish species, Amblypharyngodon mola and Puntius sophore of the Eastern Himalayas were determined. In the raw and fried samples, docosahexaenoic acid was significantly higher (2.907 and 1.167mg/100g) in Amblypharyngodon mola and lowest (0.749 and 0.291mg/100g) were recorded in Puntius sophore. The eicosapentaenoic acid of raw, fried and curried samples of Amblypharyngodon mola were recorded higher. In DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical scavenging assay of IC50 value of the raw fish extract were 2.9μg/ml and 1.66μg/ml respectively. The highest antioxidant activity was found in fish curry of Amblypharyngodon mola (0.11μg/ml). It shows that the Maillard reaction product forms the melanoidin during cooking, increases the antioxidant property of the fish curry and also improved the taste.
Single Mode Optical Fiber in Rof System Using DWDMIJERA Editor
Performance analysis was carried out to find the effect of crosstalk in a WDM system. Firstly, analysis of BER
was carried out without crosstalk. Then analysis of BER with crosstalk was done. Using equation for crosstalk,
number of channels was plotted using matlab. System parameters were optimized for a particular crosstalk.
Objective of the thesis work
Performance Analysis is carried out to find the effect of crosstalk due to optical cross connect in a DWDM
system considering a WDM based optical cross connect (OXC). An analysis is carried out to find the amount of
crosstalk due to OXC. The bit error rate performance degradation due to crosstalk is evaluated for OXC
parameter and number of wavelengths per fiber. The optimum parameters such as optimum number of channels
and hops are determined.
Routing Enhancement of MANETs using Hybrid Protocol Combined with PBOIJERA Editor
Mobile ad hoc Networks (MANETs) show an astonishing qualities in the concept of networks which are used without wires. MANETs experience numerous communication medium restrictions such as constrained storage of memory and development of effectual routing protocols. Furthermore, multihop routing mechanism employed in MANETs gives rise to the contention in the channel and jamming within the network. This limits the effectiveness of the network which reduces the energy efficiency of the network and also lessens the routing performance of MANETs. Hence, the major matter in MANETs is to minimize the congestion and contention in order to enhance the routing mechanism. Hence, in this paper, a novel protocol is put into practice having an enhanced route discovery mechanism which is implemented in order to avoid the congestion during the routing. The proposed protocol chooses the route for the transference of information on the basis of load within the traffic on the node and then resets the route with the change in topology. The protocol is then integrated with the proposed algorithm Pollination Based Optimization (PBO) algorithm. This is an efficient technique for transmission that requires a link for longer period of time. The simulator used for the simulation of the work is Network Simulator-2 (NS-2). Simulation results have been carried out showing that the route optimization and enhancement in the route discovery using Pollination Based Optimization (PBO) algorithm.
Complexity of pilgering in nuclear applicationsIJERA Editor
Nuclear reactors use various types and sections of tubes manufactured with exotic materials meeting special
requirements. These Tubes are manufactured using a Cold working process of Pilgering. Pilgering process is
influenced by a lot of factors making it a highly complex process. In this paper the various influencing factors
are compiled, segregated and briefly discussed.
Thermal Instability of Chemically Reacting Maxwell Fluid in a Horizontal Poro...IJERA Editor
The effect of chemical reaction on the linear stability of a viscoelastic fluid saturated horizontal densely-packed
porous layer is investigated. The viscoelastic properties are given by Maxwell constitutive relations. The porous
layer is cooled from the upper boundary while an adiabatic thermal boundary condition is imposed at the lower
boundary. Linear stability analysis suggests that there is a competition between the processes of viscous
relaxation and thermal diffusion that causes the first convective instability to be oscillatory rather than stationary.
The effect of Deborah number, Darcy-Prandtl number, normalized porosity, and the Frank-Kamenetskii number
on the stability of the system is investigated. Using a weighted residual method we calculate numerically the
convective thresholds for both stationary and oscillatory instability. The effects of viscoelasticity and chemical
reaction on the instability are emphasized. Some existing results are reproduced as the particular cases of the
present study.
A Versatile Control Scheme For Dynamic Voltage Restorer To Limit Downstream F...IJERA Editor
The Dynamic Voltage Restorer (DVR) is a custom power device utilized to counteract voltage sags. It injects
controlled three-phase ac voltages in series with the supply voltage, subsequent to voltage sag, to enhance
voltage quality by adjusting the voltage magnitude, wave shape, and phase angle. The DVR is conventionally
bypassed during a downstream fault to prevent potential adverse impacts on the fault and to protect the DVR
components against the fault current. This paper proposes an augmented control strategy for the DVR that
provides:1) voltage-sag compensation under balanced and unbalanced conditions and 2) a fault current
interruption (FCI) function. This paper introduces and evaluates an auxiliary control strategy for downstream
fault current interruption in a radial distribution line by means of a dynamic voltage restorer (DVR). The
proposed controller supplements the voltage-sag compensation control of the DVR. It does not require phaselocked
loop and independently controls the magnitude and phase angle of the injected voltage for each phase.
Fast least error squares digital filters are used to estimate the magnitude and phase of the measured voltages and
effectively reduce the impacts of noise, harmonics, and disturbances on the estimated phasor parameters, and
this enables effective fault current interrupting even under arcing fault conditions. The performance of the DVR
for fault current interruption is analyzed by using MATLAB/SIMULINK software.
Graphical Password by Watermarking for securityIJERA Editor
The most common authentication method is to use alphanumerical usernames and passwords. This method has
been shown to have considerable disadvantage. For example, users tend to pick passwords that can be easily
guessed. On the other hand, if a password is very difficult to guess, then it is often difficult to remember. To
address this problem, some researchers have developed authentication methods that use pictures as passwords.
Graphical Password based on the fact that humans tend to remember images better. In this paper, we will
propose a new algorithm that using watermarking technique as the solution to solving image gallery attacks and
using the random character set generation for each image for resistance to shoulder surfing attack to provide
better system security. All the information images in registration phase will be process by copy right protection
of watermarking where the login page will check this information for security purposes.
Magneto-Convection of Immiscible Fluids in a Vertical Channel Using Robin Bou...IJERA Editor
The effects of viscous dissipation on fully developed two fluid magnetohydrodynamic flow in the presence of
constant electric field in a vertical channel is investigated using Robin boundary conditions. The fluids in both
the regions are incompressible, electrically conducting and the transport properties are assumed to be constant.
The plate exchanges heat with an external fluid. Both conditions of equal and different reference temperatures of
the external fluid are considered. First, the simple cases of the negligible Brinkman number or the negligible
Grashof number are solved analytically. Then, the combined effects of buoyancy forces and viscous dissipation
are analyzed by a perturbation series method valid for small values of perturbation parameter. To relax the
condition on the perturbation parameter, the flow fields are solved by using the differential transform method.
The results are presented graphically for different values of the mixed convection parameter, Hartman number,
perturbation parameter, viscosity ratio, width ratio, conductivity ratio and Biot numbers for both open and short
circuit. The effects of these parameters on the Nusselt number at the walls is also drawn. It is found that the
solutions obtained by perturbation method and differential transform method agree very well for small values of
perturbation parameter.
Experimental Test of Stainless Steel Wire Mesh and Aluminium Alloy With Glass...IJERA Editor
At present, composite materials are mostly used in aircraft structural components, because of their excellent properties like lightweight, high strength to weight ratio, high stiffness, and corrosion resistance and less expensive. In this experimental work, the mechanical properties of laminate, this is reinforced with stainless steel wire mesh, aluminum sheet metal, perforated aluminum sheet metal and glass fibers to be laminate and investigated. The stainless steel wire mesh and perforated aluminum metal were sequentially stacked to fabricate, hybrid composites. The aluminum metal sheet is also employed with that sequence to get maximum strength and less weight. The tensile, compressive and flexure tests carried out on the hybrid composite. To investigate the mechanical properties and elastic properties of the metal matrix composite laminate of a material we are using experimental test and theoretical calculation. The experimental work consists of Tensile, compressive and flexural test. The expectation of this project results in the tensile and compressive properties of this hybrid composite it is slightly lesser than carbon fibers but it could facilitate a weight reduction compared with CFRP panels. So this hybrid laminates composite material offering significant weight savings and maximum strength over some other GFRP conventional panels
Design and Implementation of Submicron Level 10T Full Adder in ALU Using Cell...IJERA Editor
As technology scales into the nanometer regime leakage current, active power, delay and area are becoming important metric for the analysis and design of complex circuits. The main concern in mobile and battery based systems are leakage current and power dissipation. A transistor resizing approach for 10 transistor single bit full adder cells is used to determine optimal sleep transistor size which reduces power dissipation and leakage current. A submicron level 10-transistor single bit full adder cell is considered to achieve low leakage current, reduced power dissipation and high speed. In this paper initially 10T full adder cell is designed with submicron technique and later this is employed to design an ALU adder unit. The modified ALU is simulated and synthesized successfully on cadence 180nm technology.
Optimization of Pre Engineered BuildingsIJERA Editor
Pre-engineered buildings have become quite popular in the last few years. The main advantages are speed of construction and good control over quality. However there is not much information on its economy. There are several parameters like the inclination of the gable, spans, bay spacing, which control the cost of the structure. In the present paper the above parameters are varied systematically and in each case the gable frame designed for the common loads DL, LL, EQ, and WL. The quantity in each case is obtained and finally the structure which regulates the lowest quantity of steel is recommended.
Special Elements of a Ternary SemiringIJERA Editor
In this paper we study the notion of some special elements such as identity, zero, absorbing, additive
idempotent, idempotent, multiplicatively sub-idempotent, regular, Intra regular, completely regular, g–regular,
invertible and the ternary semirings such as zero sum free ternary semiring, zero ternary semiring, zero divisor
free ternary semiring, ternary semi-integral domain, semi-subtractive ternary semiring, multiplicative
cancellative ternary semiring, Viterbi ternary semiring, regular ternary semiring, completely ternary semiring
and characterize these ternary semirings.
Mathematics Subject Classification : 16Y30, 16Y99.
Secure and Reliable Data Transmission in Generalized E-MailIJERA Editor
Email is a basic service for computer users, while email malware poses critical security threats. The technique of email-borne malware will be highly effective. Email malware focuses on modeling the propagation dynamics which is a fundamental technique for developing countermeasures to reduce email malware’s spreading speed and prevalence. Modern email malware exhibits two new features, reinjection and self-start. Reinjection is an infected user sends out malware copies whenever this user visits the malicious hyperlinks or attachments. Self-start refers to the behavior that malware starts to spread whenever compromised computers restart or certain files are visited. For address this problem, to derive a novel difference equation based analytical model by introducing a new concept of virtual dirty user. Propose a new analytical model to enhanced OLSR protocol which is a trust based technique to secure the OLSR nodes against the attack. The proposed solution called EOLSR is an enhancement of the basic OLSR routing protocol, which will be able to detect the presence of malicious nodes in the network.
Enhancement in Power Quality With Grid Interconnection of Renewable Energy So...IJERA Editor
At present the Renewable energy resources (RES) are being increasingly connected in distribution systems utilizing power electronic converters. This paper presents a novel control strategy for achieving maximum benefits from these grid-interfacing inverters when installed in 3-phase 4-wire distribution systems. The inverter is controlled to perform as a multi-function device by incorporating active power filter functionality. The inverter can thus be utilized as power converter to inject power generated from RES to the grid and shunt APF to compensate current unbalance, load current harmonics, load reactive power demand and load neutral current. All of these functions may be accomplished either individually or simultaneously. With such a control, the combination of grid-interfacing inverter and the 3-phase 4-wire linear/non-linear unbalanced load at point of common coupling appears as balanced linear load to the grid. This new control concept is demonstrated with extensive MATLAB/Simulink simulation studies and validated through digital signal processor-based laboratory experimental results.
Rear Bumper Laminated In Jute Fiber With Polyester Resin.IJERA Editor
Today, a growing interest exists in the use of natural of fibers (sisal, coconut, banana, and jute), as
reinforcement in composites. The aim of the present study is shows the use of jute fiber agglutinated with
polyester resin in the automobile industry in the production of a rear bumper of hatch vehicle. A simplified
mathematical model was used for evaluation of the flaw on trunk center cover submitted to dynamic loads. The
traverse section of the referred bumper is simplified by a channel formation. This study shows that a rear
bumper made using jute fiber agglutinated with polyester resin will be possible. The molded part obtained good
visual characteristics, good geometric construction and surface without bubbles and imperfections in the fiber
and resin composite. The mathematical model to failure criterion showed that the rear bumper in jute fiber will
not resist to an impact equivalent at 4.0 km/h.
Effect of Thermo-Diffusion and Chemical Reaction on Mixed Convective Heat And...IJERA Editor
A finite element study of combined heat and mass transfer flow through a porous medium in a circular cylindrical annulus with Soret and Dufour effects in the presence of heat sources has been analyzed. The coupled velocity, energy, and diffusion equations are solved numerically by using Galerkin- finite element technique. Shear stress, Nusslet number and Sherwood number are evaluated numerically for different values of the governing parameters under consideration and are shown in tabular form.
Geospatial Technologies for Groundwater Management in Aurangabad CityIJERA Editor
The Aurangabad City is located in the heart of Maharashtra State an urban center of the Deccan sub-region. The
water provided by the Aurangabad Municipal Corporation (AMC) is not sufficient for the use of citizen. In this
study, we have only considered the water resources available in the different area only in the Aurangabad
city.All resources are mapped on the Google map/Google earth using KML platform. The Groundwater
resources available in the Aurangabadare mapped in Google earth and detail availability of the water is
provided. These ground water resources are divided into different Zones according to the availability of the
water in that particular location. The spatial data of the available water resources according tothe area are
mapped with all detail of the water available such as usage and different sources available along with their
property so it's convenient for analysis the spatial data.
Comparison Between Structural Analysis of Residential Building (Flat Scheme) ...IJERA Editor
The recent development in methods to analyze the RC frame structure brings us to this study. This paper is
approach to introduce the comparison between structural analysis of Residential building (Flat Scheme)
subjected to gravity with respect to seismic forces ( in zone II and zone III) for different storey heights.
For structural engineers, seismic load should be considered as important aspect that needs to be included in
the building design. However majority of buildings constructed in India are designed for gravity loading only
and poorly detailed to accommodate lateral loads. The purpose of this paper is to investigate the comparison
between structural analysis of residential building subjected to gravity with respect to seismic forces in zone II
and zone III for different storey heights.
The analysis for residential building (G+3) is carried out by using software SAP by seismic coefficient
method. Columns, beams and footing has been drawn. Microsoft office Excel 2007 programs were used for
drafting , and analysis of columns, beams and footing.
This analysis gives better understanding the seismic performance of buildings. The results show that the
building which is designed only for gravity load is found inadequate to resist seismic load in zone II and zone III.
Structure failure often occurs in the structure of wall. This failure can adversely affect the comfort level of the structure. Knowing the behavior of structure resulting from the load is important, as it can help to predict the strength of the structure and comfort of the structure being worked on. One way to find out and predict the strength and comfort of the structure as a result of the load received is experimental test and simulation. The simulation VecTor2 used to predict the shear force, crack, and displacement of reinforced concrete wall when applied the load. This simulation considered the effect of bond stress-slip effect of behavior reinforced concrete. Bonds stress-slip gives a great influence on the strength and hysteretic response of the reinforced concrete wall. That is why this study considers the influence of bond stress-slip on reinforced concrete wall. All the result of simulation VecTor2 using bond stress-slip effect would be compared with the result of the experimental test to see the accuracy of the simulation test.
Numerical modeling on behaviour of reinforced concrete exterior beam column j...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Seismic Capacity Comparisons of Reinforced Concrete Buildings Between Standar...drboon
Earthquakes are cause of serious damage through the building. Therefore, moment resistant frame buildings are widely used as lateral resisting system. Generally three types of moment resisting frames are designed namely Special ductile frames (SDF), Intermediate ductile frames (IDF) and Gravity load designed (GLD) frames, each of which has a certain level of ductility. Comparative studies on the seismic performance of three different ductility of building are performed in this study. The analytical models are considered about failure mode of column (i.e. shear failure, flexural to shear failure and flexural failure); beam-column joint connection, infill wall and flexural foundation. Concepts of incremental dynamic analysis are practiced to assess the required data for performance based evaluations. This study found that the lateral load capacity of GLD, IDF, and SDF building was 19.25, 27.87, and 25.92 %W respectively. The average response spectrum at the collapse state for GLD, IDF, and SDF are 0.75 g, 1.19 g, and 1.33 g, respectively. The results show that SDF is more ductile than IDF and the initial strength of SDF is close to IDF. The results indicate that all of frames are able to resistant a design earthquake.
Pull-out tests of ribbed steel reinforcing bars embedded in concrete with ste...Aaron Kadima
This paper presents an experimental study on the behaviour of the bond stress of steel reinforcing bars embedded in steel-fibre-reinforced concrete. In total, 27 specimens were subjected to pull-out tests. The main variables included the volumetric fraction of the fibre, the diameter of the reinforcing bars and the anchorage length. The results showed that the introduction of steel fibres had a significant effect on improving the bond stress performance in terms of the failure load resistance, the tensile resistance of the concrete and the reduction in the anchorage length, resulting in a more ductile bonding behaviour of reinforcing bars with smaller tested diameters. An equation to estimate the ultimate bond stress was proposed based on the prescriptions of the Brazilian design code NBR 6118, which is more accurate and considers the observed effects of the fibre addition.
Analysis of failure behavior of shear connection in push-out specimen by thre...IJERDJOURNAL
ABSTRACT:- This study analyzes the failure mechanism of shear connection by three-dimensional finite element analysis (FEA) of push-out specimens that was practically unaffordable experimentally or by twodimensional FEA. For the analysis of the failure behavior of the compression strut formed in the loaded concrete member, the three-dimensional principal stress space is transformed into two-dimensional space by means of the relation between the hydrostatic stress and the deviatoric stress. The analysis of the stress state in the compression strut revealed that the deviatoric stress increases with larger load particularly in the concrete surrounding the lower part of the shear stud. Accordingly, bearing failure of concrete occurred locally within a limited region in the slab. The steep increase of the deviatoric stress accompanying the increase of the load resulted in the failure of concrete around the lower part of the shear stud, which in turn provoked the deformation and the development of bending moment of the shear stud. Finally, plastic hinge formed in the shear stud leading it to reach its limit state. The proposed finite element model can also be used to model the shear connection of the composite beam and, the proposed stress analysis method can be applied to analyze its composite action behavior.
MODELS FOR CONFINED CONCRETE COLUMNS WITH FIBER COMPOSITESIAEME Publication
Many studies have been done to find a convenient representation of physical behavior Fiber Reinforced Polymers for strengthening or retrofitted techniques which can enhance stress-strain performance of existing reinforced concrete structures. FRP composites are used for strengthening applications mainly due to the lightweight, high compressive strength, resistance to corrosion, speed and ease of application and formed on site. Conceptually, the s tress strain relation of concrete as a non-homogenous and nonlinear composite material is not unique that depends on the many variables.
Assessing Uncertainty of Pushover Analysis to Geometric ModelingIDES Editor
Pushover Analysis a popular tool for seismic
performance evaluation of existing and new structures and is
nonlinear Static procedure where in monotonically increasing
loads are applied to the structure till the structure is unable
to resist the further load .During the analysis, whatever the
strength of concrete and steel is adopted for analysis of
structure may not be the same when real structure is
constructed and the pushover analysis results are very sensitive
to material model adopted, geometric model adopted, location
of plastic hinges and in general to procedure followed by the
analyzer. In this paper attempt has been made to assess
uncertainty in pushover analysis results by considering user
defined hinges and frame modeled as bare frame and frame
with slab modeled as rigid diaphragm and results compared
with experimental observations. Uncertain parameters
considered includes the strength of concrete, strength of steel
and cover to the reinforcement which are randomly generated
and incorporated into the analysis. The results are then
compared with experimental observations.
Effectiveness Evaluation of Seismic Protection Devices for Bridges in the PB...Franco Bontempi
Seismic protection measures for bridges can be used both for obtaining acceptable performances from new structures that for retrofitting existing ones. With the modern design philosophy based on probabilistic Performance-Based Earthquake Engineering (PBEE) approaches, the engineers are allowed to investigate different design solutions in terms of vulnerability assessment. However, if probabilistic PBEE approaches are nowadays well established and widely studied also for bridges, the topic of using the PBEE frameworks for the evaluation of the effectiveness of seismic protection devices for bridges is not extensively treated in literature.
The first objective of this work is to deal with the problem of assessing the earthquake performance of an highway bridge equipped with different bearing device: the
elastomeric bearings (ERB) and the friction pendulum systems (FPS). The second purpose is to evaluate the efficiency of a structure-dependent IM in case of isolated system. The examined structure is an highway bridge with concrete piers and steel truss deck. A FE model of the bridge is developed by using nonlinear beam-column elements with fiber section and the devices are modeled by specific elements implementing their
nonlinear behavior. The effectiveness of the different retrofitting strategies has been carried out in terms of damage probability. Choosing the example of slight damage, and referring to the curvature ductility as EDP, the probability of damage during a period of 50 years is: 23% for the structure without isolation, 7% for the structure equipped with ERB, and 3% for the structure equipped with FPS isolation.
NONLINEAR FINITE ELEMENT ANALYSIS FOR REINFORCED CONCRETE SLABS UNDER PUNCHIN...IAEME Publication
This paper presents an implementation of a three-dimensional nonlinear finite element model for evaluating the behavior of reinforced concrete slabs under centric load. The concrete was idealized by using eight-nodded solid elements. While flexural reinforcement and the shear were modeled as line elements, a perfected bond between solid elements and line elements was assumed. The nonlinear behavior of concrete in compression is simulated by an elasto-plastic work-hardening model, and in tension a suitable post-cracking model based on tension stiffening and shear retention models are employed. The steel was simulated using an elastic-full plastic model. The validity of the theoretical formulations and the program used was verified through comparison with available experimental data, and the agreement has proven to be good. A parametric study has been also carried out to investigate the influence of the slab thickness on column-slab connection response
Finite Element Analysis of the Composite Patch Repairs of the PlatesIJERA Editor
Adhesively-bonded patches are used for repair of different types of damages such as holes, notches, scratches, cracks etc. occurring in metallic as well as composite structures. The composite patching is the most widely used method of restoring the load-carrying capacity of the weakened structure. Due to the rapid growth of aerospace industry, analysis of adhesively-bonded patches to repair cracked structures have been the focus for many years. Most of these studies investigated repaired structures using linear analysis and demonstrated the viability of adhesively-bonded patch-repairs as a means to improve the durability and damage tolerance of cracked metallic structures efficiently and economically.Many researchers performed more intensive research on the method and presented the advantages of a composite material patch used for the cracked plate repairing. It was found that the bonded patch method not only reduces the weight but also increases the service life.In this research work, the analysis of cracked metallic and composite plates which are repaired by bonded-composite patches is performed using Finite Element Analysis package FRANC2D/L. This package is available with its corresponding mesh generating program CACSA. They are developed by Cornel Fracture Group, Cornel University.In this study, various fracture parameters for the structures are found out. It revealed that, the application of the bonded composite patches effectively reduces the stress intensity factor (SIF) near the crack tip and hence retards or eliminates the crack propagation. As the chances of fracture are almost reduced, the life of the structures increases by almost double of the initial. The main advantage of this patch repair technology is that, it doesn’t increase the weight of the structure too much.
A Review Paper on Analysis of T Beam Deck Type and T Beam Pre Stressed Deck B...ijtsrd
A Bridge is a structure built to span physical obstacles without closing the way underneath such as a body of water, valley, or road, for the purpose of providing passage over the obstacle. K is the portion of a bridge that acts as the roadway in the support of vehicular or pedestrian traffic. While deck parts like trusses, girders, rails, arches, posts and cantilevers assume a number of forms and types, there are relatively few bridge deck types given the utilitarian nature of the component. Rudresh Meena | Prof. Afzal Khan "A Review Paper on Analysis of T Beam Deck Type and T Beam Pre-Stressed Deck Bridge" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-7 | Issue-2 , April 2023, URL: https://www.ijtsrd.com.com/papers/ijtsrd57385.pdf Paper URL: https://www.ijtsrd.com.com/engineering/civil-engineering/57385/a-review-paper-on-analysis-of-t-beam-deck-type-and-t-beam-prestressed-deck-bridge/rudresh-meena
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
Maintaining high-quality standards in the production of TMT bars is crucial for ensuring structural integrity in construction. Addressing common defects through careful monitoring, standardized processes, and advanced technology can significantly improve the quality of TMT bars. Continuous training and adherence to quality control measures will also play a pivotal role in minimizing these defects.
Vaccine management system project report documentation..pdfKamal Acharya
The Division of Vaccine and Immunization is facing increasing difficulty monitoring vaccines and other commodities distribution once they have been distributed from the national stores. With the introduction of new vaccines, more challenges have been anticipated with this additions posing serious threat to the already over strained vaccine supply chain system in Kenya.
Courier management system project report.pdfKamal Acharya
It is now-a-days very important for the people to send or receive articles like imported furniture, electronic items, gifts, business goods and the like. People depend vastly on different transport systems which mostly use the manual way of receiving and delivering the articles. There is no way to track the articles till they are received and there is no way to let the customer know what happened in transit, once he booked some articles. In such a situation, we need a system which completely computerizes the cargo activities including time to time tracking of the articles sent. This need is fulfilled by Courier Management System software which is online software for the cargo management people that enables them to receive the goods from a source and send them to a required destination and track their status from time to time.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Democratizing Fuzzing at Scale by Abhishek Aryaabh.arya
Presented at NUS: Fuzzing and Software Security Summer School 2024
This keynote talks about the democratization of fuzzing at scale, highlighting the collaboration between open source communities, academia, and industry to advance the field of fuzzing. It delves into the history of fuzzing, the development of scalable fuzzing platforms, and the empowerment of community-driven research. The talk will further discuss recent advancements leveraging AI/ML and offer insights into the future evolution of the fuzzing landscape.
Experimental Study, Simulation and Model Predictions of Recycled PET Strip-Reinforced Concrete Flexion Members
1. F.J. Baldenebro-Lopez et al Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 7( Version 1), July 2014, pp.35-40
www.ijera.com 35|P a g e
Experimental Study, Simulation and Model Predictions of Recycled PET Strip-Reinforced Concrete Flexion Members F.J. Baldenebro-Lopez*, **, J.H. Castorena-Gonzalez**,#, J.I. Velazquez- Dimas***, J.E. Ledezma-Sillas*, J.M. Herrera-Ramirez* *(Centro de Investigación en Materiales Avanzados SC, Chihuahua, Chihuahua, México) ** (Facultad de Ingeniería Mochis, Universidad Autónoma de Sinaloa, Los Mochis, Sinaloa, México) *** (Facultad de Ingeniería, Universidad Autónoma de Sinaloa, Culiacán, Sinaloa, México) ABSTRACT This study presents results from a theoretical-experimental program of beams partially pre-stressed made with continuous recycled PET strip-reinforced concrete (plain concrete strength of 20 MPa). These studies mainly attempted to determine the stripinfluence in altering the flexural strength at first and final crack. Also the load- deflection, ductility, energy absorption capacity of the beams are observed and the studies can be used in predicting the flexural behavior of longitudinally reinforced concrete. The model theory assumes that concrete has a tensile load capacity different from zero, characterized by a uniaxial tensile stress-strain diagram. The need for non-linear geometric and the material models imply the use of numerical methods such as the finite element method; so that, a finite element analysis of reinforced concrete beam with strips-reinforced plastic is performed. The obtained results were compared with computer analysis and experimental data to corroborate the validity of the suggested method, showing that the theory also predicts correctly the post-cracking creep deformation.
Keywords- Reinforced concrete, Finite element method, Mechanical properties, Prediction model, Recycled PET strips
I. INTRODUCTION
Concrete is the most widely used construction material in the world due to its high compressive strength, durability and low cost. However, it has inherent disadvantages such as low tensile strength and cracking. Several studies about polymeric reinforced concrete have been made with the aim of improving such deficiencies of the material. The reported results show that it is possible to improve the performance of concrete by reinforcing it with different plastic elements [1]. Reinforced concrete (RC) is a composite material that results from the addition of diverse elements to the brittle matrix of ordinary concrete. Several investigations have been done on the reinforcement of structural materials using plastic elements [2-7]. In the case of concrete, the main reinforcing materials are steel, glass and polymeric strips. Some of these reinforcements are used in structures such as columns, beams and walls [8-10].
Recently the use of recycled materials as reinforcement in concrete elements has received increasing attention worldwide, being one of them polyethylene terephthalate (PET) obtained from recycled plastic bottles. PET has higher resistance to degradation, lower cost and density, and is also non- conductive of electricity and magnetism. Therefore, polymer reinforced concrete can be an excellent alternative for structures built in or near marine environments or similar corrosive environments (deicing salts), where electromagnetic neutrality and / or electrical insulation are required. Unfortunately, the use of polymers as reinforcements is not free of obstacles that must be solved before application. The main obstacles are the high initial cost, low Young modulus, low tensile strength and the absence of design parameters. The high initial cost is greatly influenced by manufacturing processes; however, different methods are currently under development to reduce the cost. The low Young modulus and tensile strength are considered the main engineering disadvantages of PET. This is because PET shows a lower safety margin when compared to its counterpart, i.e., reinforced concrete with steel bars. As for the lack of design parameters, more experimental and theoretical data are needed. It is worth mentioning that the currently available design formulas have been originally developed for steel reinforcement, and nowadays they are used by many design codes. However, these formulas are not applicable to the type of reinforcing proposed in this study. Thus, it is necessary to modify the currently used formulas to ensure a better prediction of the deflections in beams that are manufactured with these materials.
The flexural rigidity of RC beams under service loads is considerably lower than the stiffness
RESEARCH ARTICLE OPEN ACCESS
2. F.J. Baldenebro-Lopez et al Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 7( Version 1), July 2014, pp.35-40
www.ijera.com 36|P a g e
calculated on the basis of theuncracked cross-section. This is because the beam contains numerous cracks that become active under tensile stress. However, at the same time, the stiffness is significantly higher than that calculated when the tensile strength of concrete is neglected. This phenomenon, often called tension stiffening, is attributed to the fact that the concrete does not break suddenly and completely, but undergoes progressive crack nucleation, which triggers later the effect of crack growth and fracture. Based on numerous tests [11-17], Branson [18] derived an empirical formula that adequately describes the results of the tests and has been approved by anACI committee [11]. While this formula is used for practical purposes, it is not derived from the intrinsic properties of the composite material reinforcedwith strips or bands. In this article, an approach that includes the characteristics and properties that such reinforcements add to the concrete was developed. The model is able to predict the curvatures and deformations beyond the service stress range and the whole development of the ultimate load. The finite element method (FEM) is a general method of structural analysis in which the solution of a problem in continuum mechanics is approximated by the analysis of an assembly of finite element, which are interconnected at a finite number of nodal points and that represents the solution domain of the problem. The FEM is a general numerical method for the solution of partial differential equations subjected to known boundary and initial conditions, making it the most powerful general technique for the numerical solution of a variety of engineering problems. The behavior of reinforced concrete structures is distinctly nonlinear, because of several factors: (1) nonlinear material behavior of concrete and reinforcement and their interaction; (2) cracking of concrete; and (3) time dependent effects such as creep, shrinkage, temperature and load history. Nevertheless in this study only the elastic part of the composite has been carried out.
II. THEORETICAL MODELING
Figure 1 shows the arrangement of the reinforcement as well as the cross section of the beam (width H, height h), the assumed deformation profile distribution through the cross section and the corresponding stress distribution. Each row of reinforcement is referenced from the top of the cross section, and its distance is denoted by di. For the strain profile, the hypothesis to consider is that there is a linear distribution of the concrete compressive strain (εcc), concrete tensile strain (εct) and strain in a PET layer (εpi, i=1,2,3). The neutral axis (N.A.) position in the beam cross section corresponds to the distance “x” measured from the upper end of the beam cross section (Fig. 1c). In the stress distribution diagram of the beam cross section (Fig. 1d), the force (Fcc) acting in the zone under compression stress (above the N.A.) was obtained by integrating the non- linear distribution of the stress acting in this area. In the case of tension (below N.A.), the acting forces are divided into two. First the forces provided exclusively by concrete i.e., tension on the higher part (Tc1) and tension on the lower part (Tcc), and second, those of the reinforcement i.e., tension in each PET layer (Tpi, i=1,2,3). The Tc1 force is obtained by considering a linear variation of tensile stress as provided by concrete, with a maximum breaking strength value, denoted by the critical stress (fcr) in figure 1c. In the case of the Tcc force, a constant stress distribution is assumed. Tc*fcr is the maximum fracture strength. An important contribution of this research is to propose a value for the coefficient Tc. The magnitude and position of the resulting compressive strength of concrete are obtained by using the stress-strain diagram proposed by Hognestad [19] (Figure 2). In each of the points to be determined, the procedure starts by assuming the strain value εcc for the conditions under investigation, and then obtaining the depth of the neutral axis that meets the equilibrium conditions of the forces by a trial-and-error approximation. The stress-strain diagram is assumed to fit a parabolic curve as given by Eq. 1 and it is used to calculate the compressive strength of concrete in the plastic behavior region.
Figure 1. Plot of the internal actuating stresses and strains: (a) cross-section with reinforcement, (b) schematicmodel of cross-section, (c) strain and (d) stress distribution profile.
Figure 2.Stress-strain curve for concrete type Hognestad. Strain () Stress (fc) f’’c
3. F.J. Baldenebro-Lopez et al Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 7( Version 1), July 2014, pp.35-40
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2
0 0
' '' 2
cc cc
c c f f
(1)
The behavior of the Figure 2 corresponds to the
equation (1), which was given by Hognestad for
concrete(ε0, strain for f'c of the concrete in the stress-strain
curve and fc’', compressive strength of
concrete).
Deformations at each row of reinforcement were
calculated by using Eq. 2. In this manner, the tensile
stresses corresponding to the experimental stress-strain
curve of PET ware obtained (Fig. 3). The
experimental data were previously obtained by
tension tests on the PET strips along with the
longitudinal direction. An Instron 4469 universal
testing machine with a load cell of 50 kN was used
with displacement rate of 0.333 mm/s. This
procedure results in the internal forces diagram
shown in Figure 1 i.e., Fcc (Eq. 3), Tc1 (Eq. 4) where
εcr is the critical deformation, Tcc (Eq. 5), where Tp1,
Tp2 and Tp3 (Eq. 6), where Ari is the reinforcement
area and fri is the stress in a PET bands reinforcement
layer. Thereby the resisting moment Mr to the
deformation εcc can be calculated with Eq. 7 (Fig. 4),
where Ycc is the distance between N.A. and Fcc, Yc1 is
the distance between N.A. and Tc1, Ycc2 is the distance
between N.A. and Tcc.
(d x)
x i
cc
pi
(2)
0 0
'
3
1
cc cc
cc c
x
F f b (3)
cc
cr cr
c
f x B
T
2
1
1 (4)
T T f b H x
cc
cr
cc c cr
1 (5)
pi ri ri T A f , i 1,2,3,.... (6)
( )
3
1 1 2
i
r cc cc c c cc cc pi i M F Y T Y T Y T d x (7)
Figure 3.Experimental stress-strain curve of PET.
Figure 4.Distribution of forces.
The generation of points of the load-deflection
plot depends on the load conditions and support of
the beam to be studied. In this work a simply
supported beam with point center-point loading is
considered (Fig. 5). Thus the parameters to be
followed are the critical load Pr (Eq. 8) where L is the
length between supports of the beam; a calculated
curvature factor curv (Eq. 9), rigidity of the section
E*Ir (concrete Young modulus E and moment of
InertiaIr) (Eq. 10) and the deflection of the beam at
the center of the load δr (eq. 11). Figure 6 shows the
algorithm of the calculation method of Pr andδused
in this investigation.
L
M
P r
r
4
(8)
x
curv cc
(9)
curv
M
EI r
r (10)
r
r
r EI
P L
48
3
(11)
Figure 5. Configuration of the supports and load in
the beam studied.
III. NUMERICAL SIMULATION: FINITE
ELEMENT MODELING
FEM was used to calculate forces acting on
reinforced beam (B-0.25, B-0.50 and B-1.00) and on
not reinforced beam (B-0.00),considering a load of 5
kN. It was decided to calculate the stress and strains
for these conditions, because experimentally
unreinforced beams failed under this load.
Calculations were made using the theory of small
perturbations (Cauchy Green-tensioner), for
modeling the concrete solid type deformable
elements and isotropic material were used; for bands,
an element type "shell" was used. The discretization
of the concrete beam was completed using a mesh
0.0 0.1 0.2 0.3 0.4
0
20
40
60
80
100
120
140
160
Stress (MPa)
Strain (mm/mm)
4. F.J. Baldenebro-Lopez et al Int. Journal of Engineering Research and Applications www.ijera.com
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with maximum size of 12.5 mm,the objective was to replicate the dimensions of the concrete aggregate.
IV. RESULTS
According to Fig. 1, the purpose of this work was to determine the value of the coefficient Tc which, when multiplied by the rupture stress (fcr), results in the tensile stress distribution in the concrete. This distribution is considered in the equilibrium equations of resisting moments and forces in concrete beams reinforced with recycled PET strips (Eqs. 2-11). Figure 7 shows experimental and numerical results corresponding to the reinforced beam with bands of recycled PET at 0.25% in volume ratio (B-0.25). It is observed that the value of the theoretical and the experimental load to first crack are very similar; the value of the theoretical deflection at this load is 0.80 mm higher in comparison to the experimental, however the difference in the value of the maximum deflection increases in 3 mm. The behavior of the beams containing 0.50% of PET (B-0.50) indicates that the load and deflection to the first crack are very similar, while the calculated maximum deflection is less than the experimental for 0.2 kN (Fig. 8). In the case of the bending behavior of the beams with 1.00% of PET (B-1.00), Fig. 9, the load at the first experimental crack is higher in 0.75kN compared to the theoretically calculated load. On the other hand, in the maximum deflection the experimental crack is greater than that calculated by 9 mm. Experimental and numerical results corresponding to the beams with different ratios (ρ) of recycled PET bands reinforcement, 0.0025 (0.25 vol %), 0.0050 (0.50 vol %) and 0.0100 (1.00 vol %), show that generally for all the beams elastic and plastic behavior was predicted accurately. Table 1 presents the maximum loads obtained in each case, finding that at greater value of ρ, the percentage error in the approximation is increased, although the model continues precisely predicting the flexural behavior of beams reinforced with PET bands subjected to flexion, for three types of beams to Tc factor is 0.41.
Figure 6.Algorithm of the proposed method. Table 1.Theoretical and experimental loads.
Beam
Ρ
Results
Max load (kN)
B-0.25
0.0025
Theoretical
7.78
Experimental
7.91
B-0.50
0.0050
Theoretical
9.48
Experimental
9.11
B-1.00
0.0100
Theoretical
14.55
Experimental
13.80
Figure 7. Numerical and experimental load-deflection plots for a beam B-0.25. 051015202502468 Load (kN) Deflection (mm) theoretical experimental
5. F.J. Baldenebro-Lopez et al Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 7( Version 1), July 2014, pp.35-40
www.ijera.com 39|P a g e
Figure 8. Numerical and experimental load-deflection
plots for a beam B-0.50.
Figure 9. Numerical and experimental load-deflection
plots for a beam B-1.00.
Figure 10 shows the results of simulation
corresponding to the different ratios of reinforcement
in concrete beam. It is observed that the ratio
between percentage of reinforcement and stress
acting can be associated to the equation number 12
and to the stress distribution behavior. The behavior
of the elastic deformation in the simulated beam,
showing different percentages of reinforcing strips of
PET is shown in figure 11, in which a reduced in
displacement of up to 3%can be observed.
1.463 10 2.415 8 5.426 6 2 E E E (12)
Figure 10.Stress distribution of simulated beams:a)B-
0.00, b)B-0.25, c)B-0.50, d)B-1.00.
Figure 11. Numerical and experimental stress-deflection
plots for a beam B-1.00.
V. CONCLUSIONS
It has been shown in the literature and in the
present work that the use of recycled PET as
reinforcement material, either in the form of short
and continuous fibers or strips, substantially
improves the strength of concrete beams, as well as
their ductility and toughness. However, there is not a
model that can predict such improvements. In this
paper a methodology to predict these enhancements
has been found through the following three steps:
1.The application of equilibrium equations, 2.
The use of experimental stress-strain curves of PET,
and 3. The consideration that the concrete-PET
beams have a certain tensile strength at their lower
part.
A critical stress of 41% of the concrete rupture
stress was found to adequately satisfy the theoretical
and experimental curves of the specimens tested. The
reinforcement percentages used were up to 1% and a
condition was to place the PET as continuous strips,
in order to have a better control over the percentage
of reinforcement and its placement in layers.
VI. ACKNOWLEDGEMENTS
FJBL was supported as a graduate student by
CONACYT (grant 241960). This research was
carried out through project PROFAPI 2013/41 by
Universidad Autónoma de Sinaloa, and thanks to the
Centro de Investigación en MaterialesAvanzados
(CIMAV).
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