bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental and numerical analysis of axially loaded slender piles implementing a hypoplastic model
Authors: Subair A H , Aljorany A N 
Published: March 2021

Abstract
Multiple studies have been carried out to estimate uplift pile capacity, within three main categories: i) the experimental method, which is very costly; ii) a simpler method using load transfer mechanisms; and iii) the numerical finite element method (FEM). The predictive capacity of numerical simulation depends mainly on the constitutive model used to model the soil-structure interface at which the load transfers from the pile to the surrounding soil. A reliable constitutive model capable of capturing the main features of soil behaviour based on easily obtained parameters is thus required. The hypoplasticity model is a promising constitutive model in this respect, offering a particular class of rate non-linear constitutive model in which the stress increment is expressed in a tensorial equation as a function of strain increment, actual stress, and void ratio. The hypoplastic model thus requires only eight material parameters (critical friction angle φc
, e

c0, e

i0, e

d0 (critical, maximum, and minimum void ratios, respectively), granular stiffness hs, and the model constants n, α, and β), with two additional parameters used to simulate the pile-soil interface (kr
and

d
v
s

), which represent the surface roughness and the thickness of the shear zone, respectively. The performance of the model was verified in this work by comparing the numerical results with the experimental results for a single pile model under pull-out force with different surface roughnesses and confining pressures. The resulting good agreement between the numerical and the experimental results confirmed the ability of the hypoplastic model to simulate soil behaviour under complex conditions.
A study to improve plant layout design for minimizing production costs
Authors: Al-Bayati I I , Al-Zubaidy S S 
Published: March 2021

Abstract
Plant allocation and the costs of moving between workstations in production and manufacturing lines are among the most prominent factors affecting the total cost of production. Selecting appropriate work locations and distances between workstations is thus a key factor affecting the efficiency and productivity of a production line and thus the quality and cost of the final product. In this research, problems with a current plant layout are assessed with an eye to increasing productivity with minimum additional outlay. The aim is to improve the work flow in a pulley plant based on consequential planning of the plant layout, based on the assumption that the improved plant layout can reduce material flow distances, resulted in reduced costs of operation by about 5 to 10%.
An innovative mechanism for transmitting power from the pistons in internal combustion engines
Authors: Alnomani S N , Fadhel E Z , Hunain M B 
Published: March 2021

Abstract
Reciprocating internal combustion engines are common and thus important engines due to the many advantages they provide. Despite significant improvements being made to these types of engines in recent decades, however, they still suffer from low efficiency due to large losses in produced energy, which occur for multiple reasons. The crank mechanism is responsible for much of the observed energy loss, however.
In the current study, a new mechanism is suggested to transmit kinetic energy directly from the pistons, thus reducing energy losses associated with the crankshaft. This new mechanism eliminates the crankshaft from power transmission, limiting it to syncing piston movement. The pistons are then modified to mate with partial teething gears, which then transmit the kinetic energy directly from the pistons without this energy being negatively affected as it is by the angular position of the crank units. The testing results show that the power produced during the power stroke in the suggested engine is twice corresponding output of a classical engine.
Exploration of a plate heat exchanger utilising a phase change material: an experimental and computational study
Authors: Juaifer H J A , AbdulAmeer S A , Mahdi J A 
Published: March 2021

Abstract
In this article, the heat transfer mechanism of a phase change material (PCM) chamber during charging and discharging processes was studied both numerically and experimentally. A flat plate thermal storage system with dimensions of 500 × 100 × 12 mm, and a PCM thickness of 12 mm was thus investigated. The thermal storage material selected was commercial paraffin wax with a melting temperature of about 60 °C. A diffusion-advection numerical model was used to study heat transfer in this system, as it was observed that the experimental results were in good agreement with this model. In this way, natural convection was found to be the dominant phenomenon in the model. The effects of heat transfer fluid (HTF) temperature and volume flow rate on the melting and solidification time were also assessed, producing the finding that, by elevating the inlet HTF temperature from Th = 343 K to 348 K and then 353 K, the charging time can be reduced by up to 35%.
Uniaxial compression of bi-directionally graded lattice structures: Finite element modelling
Authors: Rodrigo C , Xu S , Durandet Y , Ruan D 
Published: March 2021

Abstract
Lattice structures are widely used in various engineering applications due to their high weight-to-strength ratio and exceptional energy absorbing performance. The feasibility of using different base materials to fabricate these cellular structures with complex geometries has been significantly broadened with the development of additive manufacturing technology. In this paper, quasi-static mechanical properties and energy absorption capability of polyamide PA 2200 (nylon 12) lattice structures were investigated by using finite element analysis (FEA) in ANSYS/LS-DYNA. Three types of lattice structures composed of body-centred cubic (BCC) unit cells were studied, including uniform lattice structures, uni-directionally graded lattice structures and bi-directionally graded structures. Finite element simulations were consistent with experimental data reported in literature. The results showed that bi-directionally graded lattice structures exhibited superior crushing resistance and higher energy absorption capacity than uniform and uni-directionally graded lattice structures. It showed that density grading design of lattice structures had significant influence on the deformation patterns and therefore, energy absorption performance.
Absorption characteristics of composite materials reinforced by zinc oxide nanoparticles and Kevlar fibres
Authors: Abed Z A , Rajab M A , Asfor A K 
Published: March 2021

Abstract
The research aims to study the effect of zinc oxide nanoparticles and Kevlar fibres on the absorption property of composite materials consisting of epoxy resins and phenol formaldehyde in different proportions. The results showed: Epoxy resins are not absorbed without adding phenol formaldehyde, which means an increase in the absorption property with an increases the proportion of phenol formaldehyde increases. The fibre strengthening also increases the absorption, so Kevlar with fibres gave the highest absorption; However, the absorption property decreases when the compounds are enhanced with zinc oxide nanoparticles as compared to the effects seen in the non-reinforced compounds.
Performance and exhaust emissions in a diesel engine fuelled with a blend including ZnO nanoparticles and nano-emulsions
Authors: Hamadi A S , Khudhur A G 
Published: March 2021

Abstract
A realisation of the need to curtail consumption of fossil fuels with high atmospheric emissions has led researchers to investigate alternatives in recent years. Nano-emulsions (NE) with water suspended at nano-size inside diesel fuel offer better air/fuel blends during the combustion process, creating fuels with higher combustion efficiency and lower emissions. For this study, a nano-emulsion with 12 W% was prepared in a high-speed homogenizer to produce an NE fuel with 26 nm effective droplet diameter, based on optimisation calculations in Design-Expert software. Three doses of zinc oxide (50, 100, and 150 ppm) with average diameters 10 to 30 nm were mixed into prepared nano-emulsion samples. Five fuel blends, Diesel, NE, NE+50 ppm ZnO, NE+100 ppm ZnO, and NE+150 ppm ZnO were then examined for performance and emissions in a four-cylinder Fiat Diesel engine at 1,500 rpm constant speed and 400 bar fuel injection pressure, with a changing operating load. Brake specific fuel consumption (BSFC) was reduced by 16.4% with an increase of 10.2% in thermal efficiency for NE+150 ppm ZnO in comparison with the neat diesel at higher loads of 352.88 kN/m2. CO, NOx, HC, and smoke opacity were also reduced by 18%, 13.2%, 17.1%, and 32.8 %, respectively for NE+150ppm ZnO. This research thus offer direction for the utilisation of ZnO nanoparticles in the reduction of exhaust emissions and fuel consumption, offering both economic and environmental benefits.
Investigating the impact of using nano-fluid as a cooling medium on photovoltaic/thermal panel system performance
Authors: Shahad H A , Abbood M H , Ali A A 
Published: March 2021

Abstract
Making use of the superior thermal properties of nanofluids is now very common, especially with regard to the cooling of photovoltaic panels to improve overall efficiency. In this work, a novel cooling system manufactured from 3 mm aluminium was attached to the rear of a monocrystalline photovoltaic module, and two volumetric concentrations of SiC/Water nanofluid were tested with different flow rates. These tests were carried out under outdoor climatic conditions in middle of Iraq at Babylon University (32.46 °N, 44.42°E) during both winter and summer. A theoretical model was thus developed in SolidWorks and simulated using ANSYS 18.2. The maximum enhancements in electrical and overall efficiency were found to be 50% and 82.41% in March with a 0.5% nanofluid concentration and 2 L/min flow rate, while the minimum enhancements were 35.4% and 34.01% in June, with a 0.1% nanofluid concentration and 0.5 L/min flow rate. The theoretical results showed good approximation to the experimental results, and the average deviation percentage of electrical efficiency for a photovoltaic/thermal system with nanofluid on 27 March was 5.58%, while on 3 June it was 11%.
Experimental and numerical evaluation of natural frequencies and mode shapes in a satellite model-plate connecting interface without vibration isolators
Authors: Dahham A W , Taranenko P A , Aljibory M W , Erpalov A V 
Published: March 2021

Abstract
This paper numerically and experimentally examines the natural frequencies and mode shapes in a satellite model-plate connecting interface installed on flexible gas-inflated jacks in order to assess the effect of external impacts on the natural frequencies of the satellite model and to thus generate a reference for appropriate vibration isolators for transportation and launch as required. The experimental determination of the frequencies and mode shapes of vibration in the system was carried out using modern software in conjunction with the hardware loading model satellite (LMS). Numerical calculation of the natural frequencies and mode shapes of the research object was performed in the finite element package ANSYS Workbench, with results suggesting that the suspension system (gas inflatable jacks) was sufficiently flexible and did not affect the natural frequencies at which the system under investigation, the satellite model-connecting interface plate, began to deform. Experimental determination of the natural frequencies and mode shapes of vibration for the satellite model-connecting interface plate was then conducted in the range from 44 Hz to 200 Hz; the differences in natural frequencies between the calculations and experiments averaged 10 to 15%.
Investigation of Harmonic Reduction Using Passive Filters in a Distribution Network in Basra City
Authors: Abood Salam B , Abdul-Wahhab Thamir M 
Published: March 2021

Abstract
Harmonics in current and voltage waveforms produced by nonlinear loads in a distribution system can be minimised using passive filters; however, implementing these filters requires the calculation of several suitable parameters for filter components. This work aimed to simulate and analyse the harmonics in the Al-Itihad 11 kV distribution system that branches off from Zubayr substation (33/11 kV) in Basra in Iraq using MATLAB/SIMULINK. Five non-linear loads were simulated to generate harmonics in the simulated Al-Itihad distribution system, and for each non-linear load three types of filters were tested: a single tuned filter (STF), double tuned filter (DTF), and C-type filter. The objectives of these filters to minimise the total harmonic distortion (THD) in the voltage and current waveforms, to minimise the total current, and to improve the power factor of the distribution system. The simulation results showed a reduction in total harmonic distortion, a reduction in the current at the main distribution feeder, and an improvement in the power factor of the feeder.
Optimal Reduction of electrical Loads Based on Priorities Developed Using a Genetic Algorithm
Authors: Hassan Y F , Merzah A N , Hassan S K Abdul , Tuaimah F M 
Published: March 2021

Abstract
Most developing countries are now working to combat imbalances between power generation and load demand. In such situations, load shedding schemes have been implemented frequently as rapid solutions for unbalanced conditions to protect networks from collapsing and to sustain stability. The conventional methods of load shedding disconnect loads without considering their priorities. In this work, a logarithmic reduction method is thus proposed to reduce loads according to the priority and criticality. A Reduction Matrix is introduced as a tuning factor scaled to the size of the network, and the paper thus presents an optimisation tool based on Genetic Algorithms, developed in MATLAB, that can be applied to minimise the error between the amount of load to be reduced and the actual load reduced in electric power systems. The proposed algorithm was tested on a practical data system sample as provided by the Iraqi Ministry of Electricity from the control center of the Iraqi national grid in Baghdad, and was shown to offer optimal load reduction with reduce error, which is necessary to eliminate the impact of load reduction in electrical networks on critical loads when total demand cannot be supplied. The simulation results thus support the effectiveness and practicality of the applied method, paving the way for its possible application in power systems.
Power Loss Reduction and Voltage Profile Improvement Using Optimal Placement of FACTS Devices
Authors: Daealhaq H M , kfajey Y F , Tukkee A S 
Published: March 2021

Abstract
The crucial role of an electric power system is to generate sufficient electricity to meet customer demands with an acceptable level of reliability in an economic manner. In recent years, Flexible AC Transmission Systems (FACTS) devices have been widely used to increase power system operation flexibility and controllability to meet this need. This paper presents an application of Differential Evolution (DE) to optimise the allocation of a Thyristor Controlled Series Capacitor (TCSC), a Static Var Compensator (SVC), and Unified Power Flow Controller (UPFC), as example FACTS devices. The objective of the research was to reduce power losses and improve the voltage profile in an IEEE 30-bus test system. The system performance was assessed with and without each FACTS device under different scenarios of load increase at up to 150% of the base case. The results obtained are encouraging in terms of reassessing electrical restructuring.
A Step-Up Controller Based on Fuzzy Logic Strategy to be Implemented in Photovoltaic Systems
Authors: Almawlawe M D H , Al-badri M , Alsakini I H 
Published: March 2021

Abstract
This paper applies an artificial intelligence or fuzzy logic strategy to improve the performance of photovoltaic systems with regard to variations of I-V and P-V characteristics resulting from irradiance and temperature variations that in turn create maximum power point (MPPT) variation, resulting in fluctuation of the DC voltage at the input of the boost step converter. A fuzzy logic controller is used to regulate this output voltage that can cover a wide operating range and does not require exact mathematical modelling, thus being cheap to develop. The performance of the DC converter based on the application of the fuzzy logic strategy was tested using MATLAB/Simulink for different values of input DC voltage within the PV system. The results show a good stabilising ability during irradiation changes and smooth signal output from the converter.
The Role of tungsten in trimetallic Co-Mo-W/γ-Al2O3 heterogeneous catalysts for efficient hydro-desulphurisation
Authors: Mahdi Fouad K , Albdiry Mushtaq T 
Published: March 2021

Abstract
This study investigates the effect on catalytic activity of inserting tungsten metal (W) into trimetallic W-Mo-Co supported on a Gamma-Alumina (γ-Al2O3) heterogeneous catalyst used for hydrodesulphurisation (HDS) in an oil refinery. Bimetallic Co5Mo15/γ-Al2O3 and a trimetallic Co5Mo14W1/γ-Al2O3 catalysts were synthesised using incipient wetness impregnation. The synthesised trimetallic Co5Mo14W1/γ-Al2O3 catalyst exhibited better catalytic performance, with an 88% hydro-removal percentage of sulphur based on an HDS reaction of petroleum naphtha as compared to the 82% for the bimetallic 5Co-15Mo/γ -Al2O3 catalyst under the same operational conditions at a pressure of 11.5 bar, a temperature 598 K, and a reaction time of 3 hr. This enhanced catalyst activity can be attributed to the presence of tungsten increasing the number of metal sites on the catalyst’s reaction surface.
Numerical Transfer Path Analysis for NVH System-Simulation Models
Authors: Pasch Gerwin , Jacobs Georg , Berroth Joerg 
Published: March 2021

Abstract
For the assessment of the Noise, Vibration and Harshness (NVH) behavior of complex systems in early phases of the development process, validated modelling methods are available that allow the prediction of structure-borne and airborne noise at system level. However, due to large model sizes, the identification of weak spots in the vibroacoustic transfer behavior and the derivation of optimization measures are highly complex, time-consuming, and mostly not practical. In the field of experimental NVH analysis, transfer path analysis (TPA) has been established as target-oriented methods for identifying vibroacoustic anomalies at system level. In this contribution, TPA methods from the field of measurement technology are selected and applied to numerical NVH system models, aiming for high accuracy and low computational effort in post-processing. The applications of the methods are shown and discussed using an elastic multi-body simulation model of a tractor drivetrain with a transient run-up of the vehicle speed as an example. The classical direct-force and component-based blocked-force TPA methods selected and adapted for this study allow for efficient calculation of the sound contributions of numerical models. At the same time, they overcome typical challenges of experimental TPA, such as exact force determination or consideration of rotational degrees of freedom. In addition, the comparison of the two methods shows that the path contributions are in general different for classical and component-based TPA and only under specific conditions the same. Both numerical TPA methods allow for the identification of weak spots in the NVH behavior in an efficient and target-oriented way.
Active vibration control of slewing drives with gear backlash
Authors: Spiegelhauer M , Schlecht B 
Published: March 2021

Abstract
Geared transmissions with high reduction ratios are widely utilized in drive technology. Common to these drives is the occurrence of considerable gear backlash. If operating scenarios with repeated reversals of the rotational direction or changing load directions occur, the backlash will be traversed. To overcome the gear play, rotation angles of several hundred degrees can be required at the motor. As a result, unwanted vibrations can occur and high dynamic loads may arise. It is shown that an active vibration control strategy based on full state feedback (LQG) allows to reduce both the dynamic overload and the time for reversing the drive. The model-based design approach relies on two angular measurements only. Multibody system simulations of an exemplary drivetrain are used to verify the possible improvements.
Acoustic Optimization of a Power Take-off Gear Box Using Numerical Transfer Path Analysis
Authors: Wischmann Stefan , Pasch Gerwin , Berroth Joerg , Jacobs Georg 
Published: March 2021

Abstract
In this contribution, a method is proposed which allows for a target-oriented structural optimization of drive train systems using transfer path analysis on a multi body system simulation with respect to the airborne sound. It combines the existing approaches of multi body simulation (MBS) and experimental transfer path analysis (TPA) with sound radiation calculations thereby creating a new tool chain to not only identify critical operation points but also critical transfer paths of an MBS model. This approach combines the advantages of elastic MBS (i.e. information about modes and forces acting between different components in critical operating points) with the advantages of TPA (i.e. identifying critical paths from the excitation to the receiver) thereby enabling the designer to numerically deduct and evaluate target-oriented structural optimizations already in early stages of the development process. It therefore reduces development times and costs by reducing iteration loops and the manufacturing of physical prototypes. The method is demonstrated on a power take-off (PTO) gear box, of which the sound pressure level was reduced by 6 dB within three virtual optimization loops that each only take a few hours by applying the proposed method.
Fault detection for sliding bearings using acoustic emission signals and machine learning methods
Authors: König F. , Jacobs G. , Stratmann A. , Cornel D. 
Published: March 2021

Abstract
Driven by the potential application of sliding bearings under wear-and fatigue-critical operating conditions, i.e. in planetary gearboxes for wind turbines or automotive engines with start-stop systems, the reliability and lifetime prognosis of heavy loaded sliding bearings under low rotational speeds is an emerging field of research. The application of machine learning (ML) offers a great potential for all kinds of engineering applications when physical models are not feasible due to their complexity. This study showcases the application of ML to wear and fatigue fault detection and lifetime prognosis for sliding bearings using acoustic emission signals.
Evaluation of Parts for Additive Manufacturing utilizing System Models of AM Plants
Authors: Winkler Marcel , Jacobs Georg , Spütz Kathrin , Konrad Christian 
Published: March 2021

Abstract
The objective of this study is to provide the design domain with knowledge about restrictive geometric parameters for AM-compatible part design. This knowledge is derived from the existing technical plant configuration and its component parameters. Parameter relationships between the AM plant configuration and the design parameters are derived from technical documentations and guidelines. The system model of an AM plant is built in SysML to formalise the complex relationships of the restrictive parameters relevant for part design depending on the AM system configuration. AM Manufacturing Models are introduced to calculate the technical constraints between AM plant components and restrictive design parameters. AM Plant Models are developed to formalise the configuration of a plant with the required parameters for the AM Manufacturing Models. A GUI is conceptualized for easy configuration setup of an AM plant.