bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanical and Piezoresistive Properties of Fibre Reinforced Concrete Pavement
Authors: Kadhim Ayad , Al-Dahawi Ali Majeed , Banyhussan Qais Sahib 
Published: March 2021

Abstract
Multifunctional Cementitious Composite (MCC) characteristics are directly related to the type and dosage of the Electrically Conductive Materials (ECMs) reinforcing the relevant concrete matrices. This study investigated the electro-mechanical capacities of concrete pavement (FRCP) with and without the addition of micro scale-carbon fibre (CF12). The mechanical and self-sensing responses of RFCP under indirect tension stress were evaluated initially; then, the effects of 0.5% and 1% content by volume of CF12 on the piezoresistivity capacities of FRCP under compressive load. These types of loads are the most common forces acting to continuously deteriorate rigid pavement. The test findings showed that adding CF12 improved the conductivity and reduced the resistivity of the concrete mixture and reduced polarisation time to on the order of zero seconds. Under indirect tension, however, the use of 1% by volume macro end hook steel fibre (S) resulted in a decrease in electrical resistivity, which was opposite to the expected change, and which suggested that a conductive network built from steel fibre cannot detect changes due to applied loads correctly. However, the CF-reinforced concrete pavement with 1% content by volume succeeded in identifying electrical resistivity changes. Moreover, the developed FRCP showed good results in terms of self-sensing under compression loads with both 0.5 and 1.0% by volume of CF. The results also showed that the use of a hybrid fibre (CF12 0.5% and S 1% by volume) enhanced the indirect tensile strength and compression strength due to CF12’s resistance to micro-cracks.
Experimental Study on the Behaviours of Post-tensioned Concrete Members with Unbonded Tendons
Authors: Peera Iqbal , Oukaili Nazar 
Published: March 2021

Abstract
This paper presents experimental results regarding the behaviours of eight simply supported partially prestressed concrete beams with internally unbonded tendons, focusing particularly on the effect of three different variables: concrete compressive strength, fc
′; jacking stress, fj
; and the prestressing index, ω. Increasing the concrete compressive strength from 35 MPa to 60 MPa was seen to lead to an increase in load-carrying capacity by about 10%. The load capacity was also affected, though to a lesser extent, by the jacking stress. The failure load of partially prestressed concrete beams with internally unbonded strands was increased by about 2.5%, to 10%, when the jacking stress increased from 0.5 to 0.7 of the strand’s ultimate strength, fpu
. The test results showed that the prestressing index was the most influential parameter among the examined variables. The experimental results of the stress increase in unbonded strands at failure and the ultimate load resistance of members were also compared to the analytical results of various standards and research methodologies for verification.
Behaviours of Ring and Circular Footings Subjected to Eccentric Loading: a comparative Study
Authors: Kadhum Mohammed Qassim , Albusoda Bushra Suhale 
Published: March 2021

AbstractThis study experimentally examined the behaviours of ring and circular footings resting on loose sand overlying dense sand based on the application of eccentric loads with eccentricity values of 0, 4, 8, and 16 mm. Many researchers have examined the effects of concentrated loads on ring footings numerically; however, few studies have taken into account the effect of eccentric loads on ring footings on loose and dense sand, and even fewer have done so experimentally. This paper thus presents the experimental work done to understand and make comparisons between circular and ring footings under such circumstances. The results of the tests indicate that there is a significant increase in the bearing capacity and a decrease in the settlement of ring footings in comparison with circular footings under the same conditions. Further, ring footings offer approximately the same behaviours as circular footings with respect to eccentric loads. These results indicate that the use of ring footings rather than circular footing can provide improved structural performance at low cost.
Responses of buried steel pipes under footing loadings – a numerical parametric study
Authors: Al-Naddaf Mahdi , Rasheed Sajjad Emad , Sharefi Mohammed Q. , Mustapha Rahmaninezhad S. , Jie Han P.E. 
Published: March 2021

Abstract
Buried pipes are among the most important urban facilities due to their use in multiple key applications such as drainage, sewerage, oil lines, electrical conduits, and culverts. The performance of such infrastructure under different loading conditions relies highly on their design, yet adequate design cannot be achieved unless their actual behaviours are well understood. This paper thus uses numerical analyses to investigate the response in terms of vertical stresses of buried steel pipes under monotonic static footing loads. Based on a reduced-scale physical test constructed in a test box under plane-strain conditions, a finite element model was built and verified using Plaxis3D software, and a parametric study to investigate the effects of footing width and loading condition, and pipe location or embedment ratio was then conducted. The results of the numerical analyses showed that the Hardening Soil (HS) model depicted the response of the backfill material adequately. The numerical analysis results also showed that increasing embedment depth decreased the pressure on the pipe, while increasing the footing width increased the pressure on the pipe when the embankment height was twice the pipe diameter. A critical footing width of 1B was identified that was responsible for the highest pressure on the pipe when the embankment height was equal to the pipe diameter (H/D = 1). When H/D = 1, the localised footing loading condition is thus critical due to the higher vertical stresses on the pipe than seen under uniform loading.
The impact of using pure ethanol additives on gasoline fuel with respect to SI engine emissions
Authors: Kurji H J , Imran M S , Bded A S 
Published: March 2021

Abstract
A major problem in the gasoline engine operation process under heavy-duty conditions is the knocking phenomenon, noises produced in the combustion chamber during the combustion procedure as a consequence of the pre-ignition process. These occur effect of the high temperature of the air, which causes fuel to ignite without additional activation energy (spark). The octane number for gasoline fuel measures the resistance of the fuel to such auto-ignition. Experimental work was done in this study to study the influence of adding pure ethanol to conventional Iraqi gasoline fuel at percentages varying from 10% to 90% in 10% increments by volume, with various fuel properties like density, octane number, viscosity, fuel vapour pressure, and flash point temperature, measured and compared. Ethanol additives were found to increase fuel density, flash point temperature, viscosity, and octane number while reducing fuel vapour pressure. The engine utilised in the trials was a single-cylinder, gasoline engine, naturally aspirated and air-cooled. The experimental outcomes for specific fuel consumption showed decreases of up to 29% at the 90% volumetric percentage of ethanol in conventional gasoline fuel, and emissions of engine NOX, CO, and HC decreased by 67. 7%, 69%, and 61%, respectively, However, CO2 emissions increased.
Analysis of fluid flow states in viscometers in ansys software
Authors: Azziz H N , Hussein E Q , Abdulhameed M A 
Published: March 2021

Abstract
Viscometers have multiple major applications in various areas of engineering, as the fluid flow is inherently connected to the properties of fluid viscosity. This paper substantively examines the fluid flow state over a capillary viscometer to examine the stability of such flow under the effects of various geometries (variations in tube length and cylinder base shape) of capillary viscometer, using a simulation model improved by means of the application of finite element software in Ansys 16 to depict the flow in the capillary viscometer. In this work, experimental measures were utilised and implemented to evaluate various fluid properties and to observe the effects of the geometrical shapes of the viscometer on the flow properties (pressure, velocity, and temperature) and the effect of fluid type on the vortex and fluid circulation during flow.
Control analysis and simulation of multi-body systems using full state controllers
Authors: Ali H A 
Published: March 2021

Abstract
This paper simulates a dynamic model of a multi-body dynamic system with a Linear Flexible Joint cart with a single Inverted Pendulum (LFJ_IVP). The dynamic equation of motion for the nonlinear system was linearised utilising a suitable state space method with full state feedback and full state observer controllers that act as both servos and regulator systems. The results showed a significant improvement as compared with other researchers’ work using other controls, including an improvement in the response of both the cart position (the state output of the plant), which tracked the designed external input signal to within 20%, with similar results for spring deflection, and an improvement in the amount of deflection of the right angle around the vertical position by 37.24%. There was also a marked improvement in electrical energy consumption, by approximately 55.7% based on the application of the full state feedback controller. Comparing these results to those of other controllers, such as a full state observer controller, there was a significant improvement in the consumption of electrical energy of approximately 33%.
A review of the mechanical properties of additively manufactured fiber reinforced composites
Authors: Li J H , Huang X D , Durandet Y , Ruan D 
Published: March 2021

Abstract
Recent developments in additive manufacturing technologies have made it possible to print fiber reinforced composite materials that have reasonable mechanical performance. In this paper, a brief review of the additive manufacturing technologies for composites are presented. The focus is the mechanical properties of both discontinuous and continuous fiber reinforced composites fabricated by state-of-the-art additive manufacturing technologies. The deformation mechanisms are also briefly discussed. In addition, recommendations for future work are made.
Quasi-static three-point bending of metallic sandwich panels
Authors: Xia F , Durandet Y , Ruan D 
Published: March 2021

Abstract
Sandwich panels become ideal candidates in industry applications due to their excellent energy absorption ability and light weight. The cellular core of sandwich panels may experience large plastic deformation at an almost constant stress, thus the panel has excellent energy absorption capability. The current paper examines and compares the mechanical performance of sandwich panels with three types of cores (corrugated, honeycomb and lattice truss) under quasi-static three-point bending. Finite element analysis (FEA) was performed in this study and the numerical models of each panel were developed using ABAQUS to predict the deformation mode and the bending response of panels (i.e. force-displacement curve and energy absorption) under three-point bending. Two deformation modes are predicted for all three types of sandwich panels. The honeycomb sandwich panel is expected to have the best energy absorption ability among the three types of sandwich panels with the same relative density. The outcomes of the present study will thereby provide useful information for their applications in industry.
Numerical study of a re-entrant diamond structure under dynamic compression
Authors: Logakannan K P , Ramachandran V , Rengaswamy J , Ruan D 
Published: March 2021

Abstract
Auxetic materials, due to its negative Poisson’s ratio, shrink laterally when compressed axially and expand laterally when pulled axially. A re-entrant diamond structure was developed by replacing the vertical walls in a conventional re-entrant structure with diamond cells, which featured cross-linking members to make them rigid. The incorporation of the rigid diamond unit cells increased the stiffness, strength, and energy absorption of the structure. A validated finite element (FE) model was adopted from previous work, and the structures were compressed at a speed of 5 m/s in the FE model. The independent geometrical parameters of the re-entrant diamond unit cell were re-entrant wall length (L1
), diamond angle (θ2
), and diamond wall length (L2
). The FE model based on these values was thus used to investigate the influence of geometrical parameters (θ2
& L2/L1
) on the deformation mode, stiffness, strength, and specific energy absorption (SEA) of the structure. The value of diamond angle (θ2
) varied from 40° to 90° at intervals of 10°, while the length ratio (L2/L1
) varied from 0.7 to 1.2 in increments of 0.1. The specific strength was used in the discussion to account for differences in the relative density of re-entrant diamond structures.
Investigation on mechanical properties of graphene-polyurethane nanocomposites
Authors: Abbas S A , Younas T , Asadullah  , Anwar M A 
Published: March 2021

Abstract
Polymer nanocomposites are increasingly used in applications because of their improved mechanical properties compared to traditional polymers. Graphene has attracted considerable attraction as a reinforcing material in polymers in recent years due its extraordinary effect on enhancing mechanical properties of polyurethane. This paper presents the development and characterisation of mechanical properties of graphene based polyurethane nanocomposites. The yield of the graphene nano material was carried out by using the technique called liquid exfoliation as the use of N-Methyl-2-Pyrollidone (NMP) and Tetrahydrofuran (THF) solvent. Granules polyurethane was converted into blend polyurethane by heating at 100°C and then graphene nano particles were fused with pure polyurethane matrix with different percentage weight of graphene (0, 0.1, 0.3, 0.5 and 0.7 wt.%). Microstructural and Mechanical characterisation of graphene/polyurethane nano-composite matrix were carried out involving Atomic Force Microscopy (AFM), X-Rays Diffraction (XRD) and Universal Testing Machine (UTM) and results were compared with pure polyurethane. The results have shown drastic improvements in mechanical properties with modulus of elasticity increasing by 320% and elongation at breaking point increased by 134% with just 0.7 wt. % of graphene concentration as compared to those of pure polyurethane sample.
Control Strategies for Grid-Tied Inverters Based on Photovoltaic Solar Systems
Authors: Almousawi A Q , Aldair A 
Published: March 2021

Abstract
A two control strategy for a photovoltaic grid-tied system is proposed in this paper. A microgrid (MG) can be operated in a grid-tied mode or be disconnected from the grid (in an islanded mode). To interface renewable energy sources with low-voltage distribution systems, grid-tied inverters are more commonly used, however. When a MG operates in conjunction with the grid, various control techniques have been proposed based on current control (power control) in single or triple loops. In this paper, the proposed controller enables the PV solar system to run based on voltage-control (frequency/voltage) to regulate both active and reactive power injected into the grid. The MG consists of a photovoltaic (PV) array; a DC/DC boost converter to interface the PV array to a common DC-link with double loop strategy; a 3-phase inverter controlled using a triple loop strategy; an LCL output filter; and an impedance feeder used to connect the output of the inverter to the busbar of the grid. A dq-frame for voltage and current control structure is also used. A Phase-Locked Loop (PLL) mechanism is used to provide current control in order to extract (Ɵ), while it is extracted from the frequency control in the voltage control structure. Additionally, the control strategy uses feed-forward techniques to reduce the impacts of the inherent nonlinearity of the control system and inter-couplings. Two control strategies were thus designed, analysed, and validated through simulations under several operating scenarios using detailed switching models of a 23.5 kW a PV unit in PSCAD/EMTDC software.
Effects of Heat Treatment on the Corrosion and Mechanical Properties of Stainless Steel 316L as Used in Biomedical Applications
Authors: Marwan N Ali , Saad M Ali , Hamed Jamal M , Al_Hifadhi Muthanna 
Published: March 2021

Abstract
This work examines the influence of heat treatment processes, using oil and water at various temperatures as quenching media, on the mechanical, corrosion, and microstructural properties of 316L austenitic stainless steel as used as a biomaterial for temporary and permanent bone repairs or grafts and as a plate bone fixation during periods of treatment. The results show that the highest microhardness rate is obtained using normal water as a cooling media; this sample reached 157.7 Hv, a 9.97% higher value than that obtained using oil media and an 18.66% higher value than that obtained using one-hour heating. The microstructure images for the quenched samples in oil displayed more evenly and uniformly distributed carbon particles, suggesting the formation of a more pearlite structure as compared with the water-quenched samples, however. The highest polarization resistance value was obtained when using water cooling media with two hours heating time; this reached 2.849 V/μA. Dec., while the minimum value, reached 0.185 V/μA. Dec., was obtained using the hot water cooling medium. The minimum corrosion rate value was obtained using the oil cooling media; this was 0.34 × 10-5 milli-in./year, while the maximum value reached 0.86x10-5 milli-in./year for the water cooling medium with a three-hour heating duration. The resulting equivalent von-Mises stress reached its maximum value at 285.24 MPa at 150 Kg patient weight and 5 mm plate thickness. The total deformation reached a minimum value of 0.0723 mm, while the stress safety factor reached a maximum value of 2.7 for a patient weight of 60 Kg when using 10 mm plate thickness. The equivalent elastic strain and the strain energy reached minimum values of 4.7 × 10-4 mm and 0.021 mJ for a patient weight of 60 Kg when using 5 mm plate thickness, respectively.
Design of a Low-Cost Ventilator to Support Breathing for Patients with Respiratory Failure Arising from COVID-19
Authors: Ali Saad Mahmood , Mahmood Mohammed Saad , Mahmood Noor Saad 
Published: March 2021

AbstractIn this work, two new, low cost, lightweight and simple pneumatic portable mechanical ventilator prototypes that offer minimal oxygen consumption were presented in support of treatment during the novel coronavirus (COVID-19) epidemic of 2020. The prototypes were implemented in ANSYS 18.0 and evaluated using Expert Systems 11.0 software. Both prototypes devices were found appropriate for all patients with difficulty breathing, which for patients with COVID-19, includes those with all severities of illness, recovery levels, and ages, no matter what the capacity of the patient’s respiratory system. To ensure the safety of the designed devices, the airway oxygen sensors, valves, and analysers were equipped with programmable alarms and other controllable safety attachments, including a modification to enable the delivery of nitric oxide (NO) for a specified therapy treatment recommended for respiratory failure. The overall prototype device capacity was obtained in terms of tidal volume/min. (TV), which was between 0.2 to 1.6 I./breath, suggesting that the device can be used treat patients of all ages, from children to adults. The prototype device has a range of 10 to 40 breaths/min. (bpm), and for normal spontaneous breathing, at an expiratory to inspiratory ratio E:I = 2:1, the designed prototype can produce a total tidal volume between 2.02 to 32.32 l/min. For patients with moderate breathing difficulties, i.e. with E:I ratios of 1:1, between 3.03 to 48.48 l/min. was estimated, with between 4.04 to 64.64 l/min for those with high severity of breathing issues, i.e. those with higher E:I ratios above 2:1. The designed ventilator can also be used for most oxygen consumption durations as it uses any oxygen fraction (concentration) of inspired oxygen-enriched in gas (FIO2) at an efficiency at least 0.42% higher than previous similar and standard ventilator devices.
Synthesis of WO3/TiO2nanocomposites for Use as Photocatalysts for Eosin Yellow Dye Degradation
Authors: Jawad T M , Ahmed L M 
Published: March 2021

AbstractThis work focused on the modification of a WO3surface by incorporating a TiO2surface via ultrasonic techniques to produce a nano-composite in the ratio 1:2 WO3:TiO2. All materials were then characterised by x-ray diffraction, atomic force microscopy, and UV-VIS spectrophotometry. The x-ray diffraction data proved that the WO3incorporated the TiO2as a nano-composite, with an elevated mean crystal size from 17.89 nm to 40.084 nm. The atomic force microscopy analysis also indicated that all samples were spherical. An increase in reaction temperature was found to enhance photoreaction, an endothermic and non-spontaneous reaction. The activation energy value after incorporation was decreased to 14.54 kJ mol-1after the composite was formed, improving the WO3photo properties after modification with TiO2. Moreover, photocatalysis for the decolourisation of Eosin Yellow dye reaction with observed on using the WO3/TiO2nano-composite as a pseudo-first-order behaviour.
Mechanical concept development using principle solution models
Authors: Zerwas Thilo , Jacobs Georg , Spütz Kathrin , Höpfner Gregor , Drave Imke , Berroth Joerg , Guist Christian , Konrad Christian , Rumpe Bernhard , Kohl Jens 
Published: March 2021

Abstract
Cyber-physical systems (CPS) are characterized by the interaction of mechanical, electronic and information technology subsystems. Model-Based Systems Engineering (MBSE) is an approach for the cross-domain development of CPS and requires compatible methods and models for a function-oriented collaboration of the domains. However, the mechanics operate mainly component-oriented and thus cannot participate in the function-oriented development process. We propose a new modeling method that allows mechanics to develop a consistent and function-oriented system model from requirements and functions to principle solutions. The principle solution formally specifies the physical effect, active surfaces and material through which a function is fulfilled. Since principle solutions are consistently parameter-based, they can be calculated by linked external models and checked against requirements. This enables to examine possible solutions for functions at an early stage without having to develop components. Since principle solutions consist of recurring elements, we also propose a modeling concept for a solution libraryso that proven models can be efficiently reused and the modeling effort is reduced. Modeling method, test and solution library are explained using the example of an electric water pump of an automotive cooling circuit.