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Go to Editorial ManagerOver the past years, researchers have been focusing on development the robotics and actuation due to increase demand for these applications like industrial engineering, oil industry, healthcare, aerospace … etc. This work involves the design, construction and control of the Shape Memory Alloy (SMA) actuator. The industrial actuator has many characteristics able to be measured, which have an impact on the efficiency and effectiveness of the actuator while the execution of its tasks. The most important measurable characteristics are repeatability and accuracy. The current system typically is using Nitinol (Nickle Titanium Naval Ordinance Lab), which is one of the Shape Memory Alloy that contract when applying specific heat on it, and it can be used as an actuator. This work presents SMA in the shape of a spring to operate and control the accurate position of the 2-D system which containing four SMA springs, two SMA springs for the x -axis and two SMA springs for the y - axis. The theoretical design and calculations for SMA springs have been presented to collect information about the SMA springs. In a practical manner, the SMA spring characteristic like force and displacement were collected by a test bed that was designed and constructs before making the final rig. The setting shape of the SMA spring was presented and done as per the theoretical calculations. In the rig, each axis works as a two-direction actuator, the actuator is not prone to precise position points due to hysteresis and temperature variation. The SMA spring exhibited hysteresis and imprecise pointing, for that employing PID (Proportional Integral Derivative) with tracking mode controller to compensate the hysteresis. PID control system is played a decisive role with tracking mode model that achieves the aim behind the construction of the experimental rig. Good results have been obtained presented in three cases of drawing different shapes.
This paper deals with the computer simulation of stress distribution in a plane model of mild steel under biaxial tensile loading. The goal is to visualize the crack behavior under deferent ratios of biaxial loading through linear elastic fracture mechanics theory. A finite element method is considered in calculating the mixed mode of stress intensity factor that governing the influence of stresses distribution around the crack. Aspects of crack propagation are considered. It is found that the mw.imum ci..-cumfcrcnce .stress is not of the plane of crack but that inclined by an angle (68) from it.
Groundwater in arid and semi-arid regions, such as the studied area (Safwan Al-Zubair area, south of Iraq), is of specific meaning as a major source for domestic use and irrigation demand. There is a need to better understand the interactions between groundwater and surface water (Shatt Al-Basrah Canal). These interactions can negatively affect the quality of groundwater in this area, especially that the water of Shatt Al- Basrah Canal contains highly concentrated pollutants. The aim of the study is to investigate the temporal disparity of river-aquifer interactions and count the amount of river interchange among canal and aquifer. In this research, a new concept of paradigm will be advanced utilizing RIVER package of Groundwater River Paradigm (MODFLOW) for the simulation of river-aquifer interaction operations. Six monitoring wells are chosen to evaluate the preliminary and historical groundwater hydraulic heads for six months and then use all collected data in Modflow to execute the simulation of numerical modeling to assessment the interaction between surface water and groundwater. The amount of seepage out from the canal towards the aquifer was (64.99 m 3 /day) in wet season (winter season), as a result of the high levels of the surface water compared to the hydraulic heads of groundwater. The amount of seepage in dry season towards the aquifer is equal to (336.8 m 3 /day).
The present research aims to predict the thickness distribution of a wall of a deep drawn cup. A simplified 3D axisymmetric model which represents the deep drawing set (blank and tools) was created using a CAD software, and then imported into a finite element code ANSYS where a simulation was carried out. The model represents a cylindrical cup made of low carbon steel sheet. The results showed that the FE model represents real deep drawing process fairly well. The cup thickness distribution values showed a good agreement with the referenced values, where the failure or success of drawing process could be predicted based on the obtained thickness results. It was observed that a high value of friction restrains material movement and resulted in producing more thinning and more punch force. High blank holder force was found to decrease the thickness of both the bottom face of the cup and the flange rim. While increasing die corner radius increases thickness and the maximum thinning occurred at the smallest die corner radius. It was found by decreasing the punch profile radius the thickness at the flat bottom of the cup and under the punch profile region were reduced.
In this research work, the influence of cutting parameters and drill point angle on the temperature distribution in dry drilling of stainless steel AISI 304 was numerically investigated by using FE method based on DEFORM-3D V.11 commercial software. Two cutting tools of 10 mm diameter but different in point angles, one is 110° and the other is 118°. These tools were imported from specific website in a format of STL and inserted in the program during modeling of cutting tools. The material of the cutting tools is selected as high-speed steel. The workpiece model is created as cylindrical shape with 50 mm diameter and 5 mm thickness. The cutting parameters are selected as three cutting speeds (100, 200, and 300) rpm, with three feed rates (0.15, 0.25, and 0.35) mm/rev. The depth of hole is fixed for all simulations (3 mm). The percentage of increase or decrease in the resulted temperature according to the various cutting parameter was also calculated and discussed. The best cutting performance of tools according to the change of point angles was also investigated. The results provided a significant influence of cutting speed and tool point angle on the temperature generated in the machined models and very small influence of feed speed on the workpiece temperature.
Orthogonal frequency division multiplexing (OFDM) has become a popular modulation method in high-speed wireless communication systems due to its high data rate transmission capability and robustness against multipath fading effects. One of the major drawbacks of OFDM at the transmitter side is the high peak-to-avenge power ratio (PAPR) of the OFJ)M signal. In this paper, an algorithm is proposed to reduce the peak-to-average power ratio of OFDM signal with a large number of sub-carriers. This algorithm is based on the tone reservation method. The computer simulation tests show that the suggested algorithm reduces the PAPR to a factor of S.2S dB and needs less number of iterations as compared with the traditional tone reservation algorithm.
This paper investigates the possibility of recycled aggregate use in concrete slabs with hollow cores. The main variables considered in the experimental study for the slabs were the recycled aggregate percentage and the hollow core number. Six slabs with dimensions of (1000 × 500 × 120) mm was fabricated and tested. The results showed that the addition of recycled aggregate in the concrete slabs affected the ultimate strength, ductility, and energy absorption of the concrete members. An increase of the recycled aggregate percentage to 25 % decreased the ultimate strength capacity by 3.54 %, but the increase of recycled aggregate to 50 % led to a decrease in the ultimate strength of about 6.64%. The existence of a hollow core reduced the cracking and ultimate load capacity of the RCA slabs, and this reduction was according to the core number which the fabrication of more cores caused more decrement. The ductility and energy absorption were decreased when the replacement ratio of the recycled aggregate increased. Also, the core number affected the ductility and energy absorption. The energy absorption was the most property affected by the core number increase which caused an average reduction of 71.5 % when the core number increased from two to three hollow cores.
The problem of construction debris has been emerged as one of the most important environmental problems in the Iraqi governorates due to higher rates of population growth and the need for the establishment of new construction projects to rebuilding Iraq. Therefore, this research aims to estimate the quantity of construction debris in Basra governorate and suggested method for recycling the homogeneous to rubble material that can be used in the building after admixing with cement. The study estimated the quantity of this debris in Basra during the study period, amounting to a full year up to 177.907 tons, that is equivalent to an average of 0.06 tons/m². And recycling of debris concrete to give the results of the usual approach to the concrete and be within the limits allowed in the code of Iraq and the U.S. and can be used in the production of non-loading concrete blocks.
This study investigates the deep drawing process of carbon fiber-reinforced high-density polyethylene (CF-HDPE) composites through experimental and numerical approaches. The experimental part involved fabricating CF-HDPE sheets and conducting deep drawing operations under controlled parameters (punch speed, temperature, and forming depth) to evaluate material behavior and mechanical properties. Numerically, finite element analysis (FEA) using ABAQUS simulated the forming process, analyzing stress distribution, strain development, and material deformation under varying conditions. Results revealed that increasing forming depth and decreasing forming temperature elevated the required forming force. Comparisons between experimental and numerical outcomes showed consistent trends, though some differences arose due to factors like friction and material nonlinearity. The findings contribute to optimizing deep drawing processes for composite materials, enhancing manufacturing precision, and minimizing material defects.
The direct-contact evaporation method is characterized by its effectiveness in applications of heat exchangers, especially in cooling systems, due to the absence of any heat resistors that prevent the transfer of heat between the cold and hot medium. The direct contact heat transfer depends mainly on how quickly the heat is taken by the bubbles of the evaporative refrigerant from the liquid and the increase in its volume up to the top of the heat exchanger, which is usually a cylindrical liquid column so that the temperature drop therein is uniform and even. There is much research on the method of heat transfer by direct contact. In this research, we collected and summarized most of the theoretical and practical researches that examined this method with the most important findings.
This paper is concerned with a stress analysis in a bearing under unbalanced fon:es of the jownal. Some aspects of mathematical modeling of rotating structW'Cs were considered. "Finite Element Method'' is fom1ulated for modeling rotating structures. As an application, a test rotor mounted on two-lobe hydrodynamic bearings is presented. Unbalance response calculations for various unbalance magnitudes are ca1Ticd out in the bearing location. The bearing coefficients were found at rotational speed of 4,000 rpm. An accurate identification of bearing force parameters, i.e. stiffness and damping coefficients is presented by a classical linearized model. The bearing support forces in tlexiblc rotor-bearing systems are presented as a function of unbalance response of the journal. The calculation of the bearing stress due to rotor w1balance are carried out using ANSYS. The ANSYS program gives a good aids in understanding the ~tress analysis in the bearing under the action of journal rotation.
Due to the wide use of rubber components in different engineering applications such as vibration isolators, engine mounts, car tires, and bridge bearing pads, etc. This rubber component mostly subjected to high levels of vibration and noise which are among the most reasons that lead to the failure of the structures. In the present paper has been performed experimentally to investigate the influences: different content ratios of natural rubber (NR) and polybutadiene (BR.cis) rubber blends [1: (50/50) %, 2: (60/40) %, 3: (70/30) %, 4: (80/20) %, 5: (90/10) %, 6: (100/0) % pphr], and two carbon blacks types (N375, and N220) on the dynamic properties (Rebound Resilience, Damping Time, and Decay Rate). The experimental results showed that the rubber compound that has the blending ratio [1: (50/50) %] has high resilience (low damping), high damping time and high displacement for two carbon black types used in this work. While these properties were improved whenever the rubber blend close to the percentage [5: (90/10) %]. The damping time, amplitude, and resilience of a rubber compound with a blending (90/10) % and carbon black (N220) are decreased by (24.53 %, 36.854 %, and 36.852 %), respectively, compared with a rubber blend that has the blending ratio of (50/50) %.
In this work, a portable vibration analysis and diagnosis system is designed and constructed. The system is capable of doing most of the known analysis techniques such as FFT, time waveform, cepstrum analysis, dual channel analysis, orbit, envelope detection and other techniques. Furthermore, a new fast and efficient tracking analysis algorithm, suitable for portable instruments, has been proposed. This technique provides the data required to get accurate Bode and Nyquist plots for diagnostic analysis during machine run-up and coast-down tests. Moreover, FFT waterfall and spectrogram techniques have been included. Also, single-plane and dual-plane field balancing have been implemented in this system to execute field balancing tasks.
Solar power systems, also known as photovoltaic (PV) systems, are widely used as a clean and sustainable energy source worldwide. However, these systems can be affected by various factors that contribute to dust accumulation, which have been grouped into five categories: module characteristics, environmental factors, climatic conditions, exposure situations, and soiling properties. Dust accumulation can significantly impact photovoltaic modules' efficiency and power output, leading to a decrease in electricity generation. Airborne dust reduces the intensity of solar radiation by scattering and absorbing it, especially in hot and dry regions such as southern Iraq. This study provides an updated overview of the process of dust accumulation on photovoltaic modules south of Iraq. Moreover, it illustrates the methods used to measure dust accumulation and the performance of solar PV under soiling. Furthermore, it exemplifies the sources of the soiling generation. Additionally, it demonstrates the composition and size of dust particles. Finally, future research perspectives are discussed, and a thorough investigation of the impact of dust is suggested in all regions of Iraq and even in all countries of the world, especially those interested in clean energy. This research aims to understand the effect of dust soiling on PV performance. The outcome of this research will help design the PV module system while considering the most effective method to reduce or prevent dust accumulation in specific areas.
The present work aims to build mathematical models based on experimental data to estimate the mechanical properties of submerged arc weldment. AISI 1020 low carbon steel plates 16mm thickness were welded according to orthogonal array in order to establish the relationship between input parameters (welding current, Arc voltage and welding speed) and output parameters (ultimate tensile stress, yield stress, impact energy and hardness) by submerged arc welding (SAW) process. The relationship between input and output parameters for the welding process are conducted using two suitable mathematical models the first one based on regression analysis, while the second one based on multi input single output ANFIS model for estimation of some mechanical properties of the welded plates. It was found that ANFIS results are closer to the experimental results than regression results. The optimal parameters (which give a maximum value of ultimate tensile strength (UTS), yield stress and impact energy; 446 MPa, 318 MPa and 213 J) are welding current is (380 Amp), Arc voltage is (25 V) and welding speed is (40 cm/min), while the maximum value of hardness number is (228 HV), when current welding is (380 Amp), Arc voltage is (25 V) and welding speed is (25 cm/min).
For shorter landing and take-off path in airports, the aircrafts should reduce their speed with keeping high lifting force. This paper is to identify solutions to increase the lift force of the wing significantly under several flight scenarios (such as takeoff and landing) using leading-edge slats and their relationship with the dynamic parameters of the aerodynamic wing. The study is performed by the use of ABAQUS 2016 software. The problem is solved for turbulent flow and 2-dimensional composite wing at constant Reynolds’s number of (6.49 × 10 5 ) and constant boundary conditions. Various depths have been used for the auxiliary airfoil at constant width and gap. All stresses at the wing base were obtained. The pressure distribution on the airfoil surface was determined, air velocity distribution was tracked over the surface, lift and drag forces and their coefficients were computed. The results show that the highest value of the lift coefficient is 0.489 at the depth (-3 %) of the wing chord, it decreases when the depth of the slat becomes zero %, and the rise returns with increasing depth to (4 %), but it does not reach the maximum value, while the highest drag coefficient was (1.89) at depth (4 %) of the wing chord. The maximum value of Von Mises stress was found at depth of 4 % with value of 1.605 × 10 5 Pa.
A two-dimensional finite element method for analysis and determination of second mode stress intensity factor (KII) of several crack configurations in plates under uniaxial compression is presented in this study. Various cases including diagonal crack (i.e. corner crack, central crack as well as at different locations on the diagonal) and central kinked crack are investigated with different crack's length, orientation and location. The influence of the contact between two crack surfaces is taken into account by applying contact element procedure with desired friction coefficient. The stress intensity factor is calculated by a crack surface displacement extrapolation technique. From the obtained results of the analysis it is found that, the corner cracked plates more dangerous than the other cracked plates, since it has the highest stress intensity factor. Also, the length and orientation of the kinked crack have significant effects on the stress intensity factor. The results of this investigation is illustrated graphically, exposing some novel knowledge about the stress intensity factor and its dependence on crack configuration.
This review focuses on the experimental and numerical studies of sweeping impingement jets that serve in cooling of hot surfaces. It is known that the impinging jets produce high-localized heat transfer coefficient. The sweeping jet covers a wider area on a hot target to improve the heat transfer rate, they could be used to increase the cooling rate of the impingement surface by disturbing the boundary layer. To display a readable survey, the current review was partitioned to four groups based on engineering configurations. The review shows that the sweeping nozzle gives better efficiency in heat transfer, improved Nusselt number and uniform target surface temperature, compared with the conventional normal jets. The current review reveals that the sweeping-jet mechanism can be achieved either by fluidic oscillator or by exciting a flexible wall forming an oscillating jet. Most of the fluidic oscillator researches are conducted experimentally (27%), while the researches that use flexible wall are about 24%.
This study focuses on the design and construction of an automated device for evaluating the scratch resistance of polymeric materials by measuring the force required to produce surface scratches and calculating the corresponding friction coefficient from device input–output data. The device was fabricated using locally available materials, with several components manufactured in local mechanical workshops. It comprises four main subsystems: mechanical components, scratching mechanism, electrical and electronic units, and an operating control program. The developed device offers the following specifications: normal load range of 0.1–325 N, sliding speed of 1–35 mm/s, tangential force measurement capacity of 0.1–294 N via a load cell, sample dimensions of 10–195 mm in length, 10–125 mm in width, and 0.25–50 mm in thickness, a maximum scratch length of 195 mm, and an adjustable indenter height ranging from 0.25 to 50 mm above the platform surface. Scratch testing and friction coefficient measurements were conducted on pure PMMA and PMMA reinforced with silicon dioxide (SiO₂) nanoparticles. Experimental results demonstrated increased scratch resistance and reduced friction coefficients with higher SiO₂ weight ratios. Additionally, the performance evaluation confirmed that the designed device is capable of accurately and rapidly measuring the tangential forces associated with scratching through a simple operational procedure.
In this research, the mechanical properties were studied from the experimental, theoretical, and numerical aspects of the sports prosthetic foot for the purpose of providing a sporty prosthetic limb with high performance, easy to use and an appropriate financial cost to use by amputees who have lost their lower limbs (amputation below the knee) in practicing their sports activities and overcoming physical disability. The dimensions of the blades were calculated based on side profiles from European patent specifications. The chosen fibers have high strength, are light in weight, and can be purchased for a lower price than the materials that are used in the production of the sports prosthetic feet that are already on the market and are produced by specialized companies such as Ottobock and Ossur. Six laminates of the composite material consisting of matrix orthocryl lamination 80:20 pro reinforced with different fibers (Kevlar fibers, carbon fibers, glass fibers, and perlon fibers) were fabricated in the form of rectangles using the vacuum system and then cut to the required dimensions using a CNC machine. The density and volume fraction of the samples and the use of the rule of mixtures to calculate the mechanical properties of the laminates were calculated and entered into the ANSYS program. Then the boundary conditions were applied to the athlete's prosthetic foot and the total deformation, and the total strain energy was calculated to find out the best laminates in the athlete's foot industry. It was noticed that the laminates reinforced with carbon fibers were better than the laminates reinforced with glass fibers in terms of Young’s Modulus, as well as deformation. The best laminate obtained is (12 K + 4 C).
The analysis of raw domestic sewage has a greater importance for design of an effective and economic rational sewage treatment. The objectives of this study are to determine the chemical, physical and Biochemical characteristics of raw domestic sewage for Basrah city. Results show that; the strength of Basrah raw domestic sewage can be classified as a strong strength concentration wastewater due to high levels of organic loading rate BOD5 , COD. Also, it can be seen a very high concentrations of TDS , CL- and increasing in EC levels above the typical limits due to the salinity of domestic water supply in Basrah. High concentrations of oil and grease were found as result of misuse of the sewerage system. While the values of pH, temperature, nutrients and the number of FC are within the typical acceptable limits.
This article provides an overview of the studies that have been conducted on the characteristics of epoxy resins containing various types of silica nanoparticles and microparticles, as well as their performance in the industrial application of functionally graded materials (FGMs). Silica nanoparticles and microparticles are used to create epoxy resins in order to improve various properties, such as thermal stability, adhesiveness, electrical conductivity, strength, modulus, and toughness. This review examines the literature that has been published in the last decade, compares the results, focuses on the mechanical and thermal properties, and discusses the changes that have resulted in improvements in those properties. Previous experimental findings are presented and contrasted to demonstrate the extent to which silica filler content contributes to improving the properties of composite materials. The findings reveal that the characteristics of epoxy compounds can be improved by adding a particular amount of silica particles. There is a correlation between an increase in the silica amount and an increase in the Young modulus of epoxy compounds, this correlation becomes stronger as the silica amount increases. Additionally, the tensile strength of epoxy compounds increases to a certain limit as the amount of silica nanoparticles increases. In contrast, the hardness of the material increases as the silica amount increases. The density of the material also increases steadily as the silica amount in the material increases. According to thermal analysis results from calorimetric research on epoxy–silica systems, the glass transition temperature increases as the silica amount increases.
This paper introduces a radial distribution feeder protection scheme based on certain features extraction from current signals measurement at the substation. The features are captured using the discrete wavelet transform (DWT). Two digital signals processing methods are used to introduce those features to the 1) fault detection 2) identification and 3) localization schemes; the first one is the energy method and the second one is the root mean square method. For the purpose of fault type identification, two systems are tested and compared, a Fuzzy Inference System (FIS) and Artificial Neural Network (ANN). Fault location scheme is then built based on ANNs. An effort is made to reduce the computational burden and the speed of detection provided by the fault detection and identification schemes. Since the short circuit faults are the most likely types of faults that can occur in power systems, the ten types of these faults taking into account different fault resistances are simulated in MATLAB environment and the protection scheme is built based on the idea of over current. The power quality disturbances such as switching transient events on the feeder is also taken into account in order to build a reliable and secure protection scheme.
Four groups of AISI 1020 specimens were heat-treated at 850 °C in a muffle furnace for 30 minutes then quenched in oil. The samples were tempered at 400 °C with a time period for each group as (group B, 2 hours), (group C, 3 hours), and (group D, 4 hours). The mechanical properties of the samples were studied using universal tensile testing equipment and a Brinell hardness testing machine. The hardness values of the quenched samples were calculated from a given modified equation. The torsional fatigue behavior of AISI 1020 was discovered in this investigation for heat-treated specimens and compared with the original specimens. All groups were subjected to an analysis using an optical microscope. Pearlite is formed when is heated in the austenitic region and then cooled below a lower critical temperature. It was concluded that the heat treatment increases the hardness for the specimens while decreased the shear fatigue ductility coefficient. Also, the heat treatment increased the shear fatigue strength coefficient. Furthermore, increasing in the time period of the tempering process was leaded to decrease the coefficient of shear fatigue strength and increased the coefficient of shear fatigue ductility.
The aim of the present paper is to investigate buckling phenomenon of various cracked plates under compression load. The finite element procedure (ANSYS Package) is used to determine the critical buckling load by considering the effects of crack length and crack location (i.e. crack parameters) as well as loading direction parallel or perpendicular with respect to crack faces. It is found from the obtained results which are summarized graphically in figures that the crack parameters and loading direction have significant effects on the critical buckling load (i.e. increased or decreased) of compressed cracked plates. The effects of these factors are discussed in detail. The useful and interesting conclusions drawn from this work will be helpful for health monitoring or condition assessment of aging plated structures with cracking damages.
The rotor unbalances and misalignment in rotary machines are two major sources of vibration. rotor unbalance and misalignment is omnipresent in all rotating machinery widely used in many industrial applications, posing a serious threat to machine life and operation. The present work is an attempt to investigate the vibration characteristics (Amplitude, FFT, and time waveform) of a rotating mechanical system, which has an unbalanced rotor and misalignment. Vibration signals are acquired using an accelerometer mounted on the bearing housing nearer to the rotor. The FFT analysis of the acquired data revealed the response of an unbalanced rotor under operating conditions. Numerical analysis of the system using ANSYS portrayed the modal frequencies and mode shapes. Transient Structural analysis illustrates the response of the system to different mass unbalances. The results revealed that the magnitude of vibration characteristics significantly increases with excitation frequency and exciting force.
In this research ,the sediment load in Shat Al- Gharaf River , lies in the south of Iraq ,has been studied . Two empirical formulas those have been presented by ; Bagnold and Van Rijin were adopted as a deterministic equations for computing the sediment discharge in selected reaches of river . The application of these equations requires to do different hydraulic , sediment , and geometric measurements for the selected reaches . Accordingly , thirteen sections along the river within a study area have been adopted . After analyzing the available data , a new formula for estimating the suspended sediment load in Shat Al-Gharaf was developed , depending on the data for ten sections of this river and by using SPSS program , the determination coefficient of the new formula was (R 2 =0.94) . The validity of the established formula has been verified using some well related (i.e., nearly the same hydraulics and geometrical circumstances) of field data over the world was selected from published literatures [8] these are : Colorado river data of the U.S.B.R.(1958) ,River data from Leopold (1969) , and India canal data of Chaudry et.al.(1970). As well as ,those observed in the remaining three sections of present river , the verification shows a good agreement . The results of the adopted two formulas and the new formula were compared with field measurements using Discrepancy Ratio (bais) method . The suggested new formula gave the best results where 50% of data located within a discrepancy ratio close to one and 30% of data located within an error ±20% , that is refer to suitability adoption this formula as a deterministic equation to estimate the sediment load in Shat Al-Garaf river within a study reach .