bluuebunny/crossref_metadata_2025_split huggingface dataset:
Friction modelling in sheet metal forming simulations for aluminium body parts at Daimler AG
Authors: Bolay C. , Essig P. , Kaminsky C. , Hol J. , Naegele P. , Schmidt R. 
Published: November 2019

Abstract
Tribology plays a key role in the production of high-quality car body parts. In forming simulations, often a constant value for the friction coefficient is used, which limits the overall simulation accuracy. In reality, friction depends on the pressure distribution, forming velocity, interface temperature, plastic strain, type/amount of lubrication and the surface topography of both the sheet and the tooling. The simulation accuracy, and therefore the prediction of the formability of complex geometries, can be improved significantly by taking all these parameters into account. This paper presents a selection of results for 2 aluminium cases: 1 scientific part conducted at the IFU Stuttgart and 1 complex body part from Daimler AG. Simulation results have been validated by experimental results to show the influence of friction on e.g. part quality, draw-in and spring-back. Results show that friction modelling becomes increasingly important in the stamping process of aluminium parts, and that the overall simulation accuracy increases when accounting for the actual tribological conditions in stamping.
Die Quench Process Sensitivity of AA7050
Authors: Boulis R. , DiCecco S. , Worswick M.J. 
Published: November 2019

Abstract
The current work investigates the sensitivity of AA7050 aluminum alloy sheet to the thermal cycle involved in the die quenching (DQ) process. This entailed the variation of three key parameters in the thermal cycle, namely solutionizing time, transfer time and quench rate, considering both water quenching (WQ) and die quenching (DQ) at various die pressures. Following a lab-grade T6 heat treatment, Vickers hardness (HV-1000) measurements of all test conditions and tensile testing on a reduced number of test conditions were completed. The results showed only limited sensitivity to solutionizing time for the range of conditions tested. Longer transfer times and slower cooling rates both negatively affected final hardness properties, with up to 4% reduction in final hardness relative to the water-quenched T6 condition. Higher cooling rates during die-quenching produced statistically similar final tensile properties to those achieved from water quenching, following a T6 heat-treatment; while slower cooling rates resulted in significant reductions in tensile strength and uniform elongation. Limiting dome height testing of a 101.6 mm dome sample under die-quench conditions produced a major true limit strain of 0.42. The die-quench limit strain compared favourably against the limit strains of the same geometry in the T6 condition at room temperature and 150 °C (isothermal), which were 0.12 and 0.18, respectively.
Prediction of forming limit diagrams using machine learning
Authors: Chheda Amar M , Nazro Louis , Sen Fatih G , Hegadekatte Vishwanath 
Published: November 2019

Abstract
Measuring forming limit diagrams (FLDs) is a time consuming and expensive process. Data-driven and artificial intelligence approaches have been used to facilitate finding relationships between alloy composition, and manufacturing processing conditions with mechanical properties of materials. Machine learning (ML) methods are a promising route to predict FLD of aluminium alloys that are increasingly used in automotive structural applications. In the present work, we developed a machine learning (ML) based tool to establish the relationships between alloy composition / thermomechanical processing route to the material’s FLD, which is a measure of formability. Measured FLDs of various 5XXX and 6XXX aluminium alloys along with their chemical composition and thermomechanical processing parameters like homogenization, hot and cold rolling parameters etc. and the respective mechanical properties like n and r values were manually curated and stored in a database. A two-stage ML model was trained on this database. In the first stage, the minimum and maximum points of the minor strain were predicted using a feature set incorporating chemical composition, thermomechanical processing parameters, and n and r values using support vector regression (SVR). In the second stage, the predicted minor strain in the first stage was used as input in addition to the same feature set to predict the major strain using gradient boost regression (GBR). The trained ML model successfully predicted FLDs with R2 value above 0.93. To study the impact of the difference between a predicted and a measured FLD on stamping simulation results, finite element simulations of a cross die were performed. The difference in draw depth of the cross-die using the predicted FLD and the measured FLD was between 5 to 10%. The current results show that ML can be a viable way for predicting FLDs.
Simulation of the optimal control of a reagent supply in the in-situ uranium leaching process
Authors: Sadykov M P 
Published: November 2019

Abstract
This article develops an optimization task model for a physicochemical process that takes place in a mineral-bearing formation at the in-situ leaching of mineral. As a result of research, a certain hydrodynamic pressure and velocity field are obtained in a reservoir under the action network of wells, distributive reagent concentrations, mineral in a solid and liquid phase. Furthermore, according to this technique, the intensity-reagent impacts are studied on an extraction degree and mineral extraction time.
The neural networks application in predicting the geometrical parameters of coatings formed on a steel substrate by laser alloying
Authors: Ulakhanov N , Mishigdorzhiyn U 
Published: November 2019

Abstract
A mathematical model for predicting the geometric parameters of boron and aluminum-based coatings formed on a steel substrate by laser alloying is presented in the work. The model combines the principles of the theory of experiment planning with an artificial neural network (ANN) apparatus. Coatings were formed by means of laser heating of the steel surface with a pre-applied treatment paste. The ANN was built, trained and tested for the prediction of the width and depth of the molten bath on a steel substrate. The prediction results of the obtained neural network were compared with the corresponding linear models. The efficiency of the considered approach and the possibility of its application for predicting the values of laser treatment of steel parts of machines subjected to surface hardening are shown. The presented approach allows to use one mathematical model for predicting several parameters, thereby reducing the number of experiments.
Modeling and optimization of the processes of turbulence
Authors: Lvovich I Ya , Lvovich Ya I , Preobrazhenskiy A P , Choporov O N 
Published: November 2019

Abstract
In this paper the problem associated with the modeling and simulation of turbulent flows is considered. Turbulent flows are quite common and a complete theory is not built for them at the moment. Among the models that are based on the subgrid scale, the model proposed by Smagorinsky was chosen. On the basis of the created subsystem in the form of a cross-platform dynamic library for modeling turbulent media, the simulation of water flow around a circular obstacle was carried out. The simulation results are presented. Suggestions are given for the optimization procedure, with variations in the implementation of the considered system of medium motion.
Application of a discrete model of fatigue defect growth for assessment of the safe operation life of the main pipeline section with a corrosion defect
Authors: Vansovich K , Aistov I , Nakhlestkin A 
Published: November 2019

Abstract
The article proposes a model of fatigue defect growth obtained on the basis of the analysis of the three-dimensional stress state at the apex of the corrosion defect. To study the stress-strain state the actual operational loads of the pipeline were simulated by the finite element method. The scientific novelty of the study is that when developing a model of fatigue defect growth, it is assumed that the growth of the defect, which develops by the opening fracture mode, is controlled only by normal stresses. In one loading cycle, the intensity of the fracture process is determined by both the maximum tensile stresses during the loading period and the maximum compressive stresses during the unloading period. Based on the assumptions made, it has been established that the growth rate of fatigue defects of corrosion origin depends on the magnitude of the coefficient of the average stresses change ahead of the crack front during full loading cycle.
Stretch elasticity and garment pressure of shaping-underwear fabric
Authors: Gong Yun-Qi , Mei Shun-Qi 
Published: November 2019

Abstract
In recent years, the relationship between corsets and human health has been widely concerned. In order to explore the relationship between body shaping fabric and garment pressure, this paper starts from the reasons for the formation of body-dressing clothes, discusses the comfort range of human body wear and summarizes the principles, advantages and disadvantages of various methods of testing body-dressing clothes. At the same time, five elastic fabrics are selected to test their tensile properties. The garment pressures produced by the human calf diameter of 9 cm are also tested. The relationship between the tensile properties of the fabric and the garment pressure is analyzed, which lays the foundation for designing the intelligent corset that can meet the health requirements of people and realize the shaping of the body.
Synthesis and antimicrobical activity of composite oxides nanoparticles based on ZnO
Authors: Kondranova A M , Lozhkomoev A S , Kazantsev S O , Pervikov A V 
Published: November 2019

Abstract
It should be noted that zinc oxide nanoparticles have increased antibacterial activity. ZnO/Me composite nanoparticles have a more pronounced antimicrobial effect in comparison with monometallic nanoparticles obtained by similar conditions. In present work ZnO/Ag and ZnO/CuO composite nanoparticles were obtained by the electrical explosion of Zn and Cu or Zn and Ag wires in oxygen containing atmosphere. Composite nanoparticles were characterized by transmission electron microscopy, XRD analysis and micro electrophoresis. Antibacterial activity of composite nanoparticles against Gram-positive E.coli and Gram-negative MRSA was studied. The as-synthesized nanoparticles demonstrated excellent bactericidal effect due to their unique properties including not only components additive effect but also synergetic one.
Mathematical modelling of the process of melting alloys of the Si-Cr-Ni-Fe system in the iron-carbon melt
Authors: Zayakin O V , Renev D S , Zhuchkov V I , Lozovaya E Yu 
Published: November 2019

Abstract
The process of melting of the Si-Cr-Ni-Fe ferroalloys in the iron-carbon melt under static conditions was studied using the method of mathematical modelling. It was found that the melting process takes place in three stages. The effect of silicon concentration and the initial size of a piece of alloy on the duration of each stage of alloy melting is revealed. It was shown that an increase in the silicon content from 6 to 40 % in the complex ferroalloy of the 50 mm fraction containing ~ 27 % Cr and ~ 12 % Ni leads to a decrease in the total melting time of the alloys from 67 to 30 seconds at the iron-carbon melt temperature of 1600 ºC.
Analysis of the possibility of using Cu-Au nanoclusters as bits in phase charge memory devices
Authors: Bashkova D A , Gafner Yu Ya , Zamulin I S , Kuznetsov M F 
Published: November 2019

Abstract
This work analyses the potential of using copper-gold nanoalloy as a material for phase charge memory cells. For this purpose, smooth cooling of the melt of Cu-Au nanoclusters of 2.0 – 8.0 nm diameter was simulated with the molecular dynamics method, based on the modified tight-binding potential (TB-SMA). Particles of different chemical compositions were investigated. The gold content in the alloy varied from 10 to 90 percent. The authors also explored the influence of the cooling intensity on the character of the formed substructures. To reach the goal, the values of the heat removal rate were varied. As a result, nanoclusters of compositions Cu90Au10 and Cu10Au90 were found in a range of particles. Some parameters were selected for them, at which the stable development of amorphous and crystalline structures is possible.
Definition of preferable thickness of metal cylindrical panels with mild camber based on post-buckling behaviour due to compression
Authors: Mitrofanov O V 
Published: November 2019

Abstract
Engineer design methodology for metal cylindrical panels with mild camber with post-buckling behavior accepted in case of compression above limit level is suggested. Method is based on geometrically non-linear task analytic solution and is reduced to solution of non-linear equation in panel thickness with limit stress being reached with post-buckling behavior of rigidly supported panel taking into account initial deflection.
Post-buckling behaviour estimation of thin cylindrical composite shells of non-symmetrical structure in case of compression
Authors: Mitrofanov O V 
Published: November 2019

Abstract
The paper deals with the result of analytic solution of the geometrically non-linear task for composite thin-walled cylindrical shell post-buckling behavior in case of axial compression by using Bubnov-Galerkin method. Initial correlations take into account composite structure non-symmetry.
Design of cylindrical composite panels with mild camber for biaxial compression taking into account geometrical non-linearity with uniform heating and rigid support
Authors: Mitrofanov O V , Klesareva M V 
Published: November 2019

Abstract
Based on geometrically non-linear task analytic solution for cylindrical composite panel with mild camber method of best possible design for post-buckling state with biaxial compression is suggested. Uniform heating and panel all-boundary rigid support are taken into account in basic correlations.
On an optimization method of chemical reactors
Authors: Burlakov I D , Buldaev A S 
Published: November 2019

Abstract
The class of model problems of optimal process control of chemical reactors is considered. A new method of constructing successive approximations to the optimal problem solution is proposed, based on the implementation of the constructed conditions for improving control in the form of fixed-point problems. This form allows to apply and modify the theory and methods of searching for fixed points to optimize control. A comparative analysis of the effectiveness of the proposed optimization method with well-known computational algorithms in the calculation of specific model problems of optimization of chemical reactors is carried out.
Determination of the geometric characteristics of fatigue cracks by digital image processing method
Authors: Bazaron S A , Damdinova T Ts , Bochektueva E B 
Published: November 2019

Abstract
The article deals with the problem of determining the rate of crack growth in the process of fatigue failure of helicopter part samples. The studies were conducted using a video recording of the experiment. Methods of digital image processing were applied to the frames of the video recording to process the data of the object destruction process. Based on the developed algorithm, computational experiments were carried out, the geometric parameters of the cracks were determined for calculating the rate of change in their sizes. The use of digital image processing methods allows significantly improve the accuracy and reduce the processing time of experimental data.
Strength evaluation of the relocatable building made of the polymer composite material
Authors: Bokhoeva L A , Baldanov A B , Kurokhtin V Yu 
Published: November 2019

Abstract
The article deals with the problem of improving the efficiency of the frame relocatable building structures by perfecting structural forms, introducing sound and lightweight materials, in particular, polymer composite materials (PCM). For this purpose, we have developed an engineering calculation algorithm using CAD / CAE systems and considered various options for deposition of PCM layers. The analytical formulas that determine the Eulerian instability for PCMs are compared with the values in ANSYS.
An experimental research of the laminated composite plates stability
Authors: Bokhoeva L A , Bochektueva E B 
Published: November 2019

Abstract
The article shows the results of experimental studies of stability, supercritical behaviour and fracture of plates of a layered composite material. Composite plates are made of fiberglass layers glued with epoxy resin. To reliably assess the bearing capacity of laminated plates, numerical and experimental methods are used. A methodology for experimental research of the deformation and strength properties of composite materials using testing equipment has been developed. The difference between the critical strength values of three-layer samples and the critical strength of four-layer samples was determined to be 2-3%. Thus, products from composite materials (unmanned aerial vehicles) can be made from three-layer plates to reduce their weight. Models of two-layer, three-layer, and four-layer plates were performed with the ANSYS program. The obtained experimental results were compared with numerical values. The possibility of using experimental data of the mechanical behaviour of layered composite materials in the design and calculation of unmanned aerial vehicles was estimated.
Mechanical properties of self-compacting concrete containing sandstone slurry
Authors: Gupta R C , Basu P , Agrawal S 
Published: November 2019

Abstract
India embraces wide variety of dimensional stones. It includes granite, marble, sandstone, limestone and slate. Amid all the states, Rajasthan is known as mineral majestic of India, with an abundance of important stones. Rajasthan produces more than 90% of sandstone of all over the country. The total quantity of mined out sandstone is 200.27 million tons per year, out of which 110.25 million tons are accounted as waste during various manufacturing and processing stages of sandstone. An experimental work has been conducted to manufacture self-compacting concrete (SCC) with dry sandstone slurry (DSS) and study the properties of SCC. Seven SCC mixes have been prepared with various percentages of sandstone slurry (i.e. 0, 5, 10, 15, 20, 25 and 30 percent) as partial replacement of pozzolana portland cement (PPC). Compressive, flexure and tensile strength of all SCC mixes up to 180 days curing age and abrasion resistance after 28 days curing age have been found out and presented in this paper. The conclusion of this study draws an idea about the use of SCC mixes made with DSS are in favor of using DSS up to 10% for reinforced cement concrete work and up to 20% for plain cement concrete work.
Rheological properties of two stainless steel 316L powders for additive manufacturing
Authors: Gong Haijun , Xing Xiaodong , Gu Hengfeng 
Published: November 2019

Abstract
This study measures the rheological properties of two stainless steel 316L powders which are used for the powder-bed-fusion based additive manufacturing process. The purpose is to evaluate the newly acquired powder in comparison with the used and recycled powder, so that both powders can be mixed with each other to supplement the powder usage. The powder rheology properties, such as dynamic property, bulk property, and shear property, are tested and compared. The results and analysis confirm the compatibility of powder mixing.
Influence of varied process parameters on the microstructure, densification and microhardness of spark plasma sintered Ti-6Al-4V/h-BN binary composite
Authors: Abe J O , Popoola A P I , Popoola O M 
Published: November 2019

Abstract
The influence of varied process parameters involving three levels of temperature, pressure, heating rate and dwell time on the microstructure, densification and microhardness of spark plasma sintered Ti-6Al-4V/h-BN binary composite was studied. Taguchi design method was adopted to randomize the SPS process parameter levels. The microstructure was analyzed by optical microscopy, densification was determined based on the principle of Archimedes and Vickers microhardness tester was used to evaluate the microhardness of the sintered composite. The consolidation of Ti-6Al-4V powder and nanoparticles of 3 wt.% of h-BN via SPS produced nearly full theoretical densification of 99.77% and the sintered composite gave a microhardness value of 710.37 HV which is more than 200% that of the monolithic alloy. The best combination of relative densification and microhardness were obtained at the sintering parameters of 1000 °C of temperature, 40 MPa of pressure, 100 °C/min heating rate and 15 min of dwell time. Generally, it was found that improved microstructure, densification and microhardness were influenced by the high temperature of sintering and low rate of heating that gave room for adequate diffusional mass transport resulting in solid bonding between the particles of the matrix and the ceramic reinforcement.
Wear and surface roughness analysis of machining of Ti-6Al-4V under dry, wet and cryogenic conditions
Authors: Ali Khan Muhammad , Husain Imran Jaffery Syed , Khan Mushtaq , Ikramullah Butt Shahid 
Published: November 2019

Abstract
Use of cooling media contributes in elevation of desired responses owing to its cooling and lubrication effects especially in case of hard to cut materials like Ti-6Al-4V. This study aims to analyze the effect of cooling media in addition to cutting speed on responses including tool wear and surface integrity during turning. Results highlighted the effectiveness of cooling system in particular that of cryogenic media. Use of cryogenic media and cutting fluid enhanced tool life max by 33% and 21% respectively. At lower cutting speed surface roughness was improved by 13% and 8% by cryogenic media and cutting fluid respectively.
Tall buildings seismic behavior comparative study by increasing the concrete mechanical strength through non-linear static analysis and seismic performance
Authors: Lopez-De-La-Cruz F , Choncen-Arboleda A , Moreno-Sanchez J 
Published: November 2019

Abstract
The use of high strength concrete in tall buildings implies less lateral displacement, however, an important question is. In what other measures the seismic behavior of a building improves with high strength concrete (550 kg/cm2). As a result, the material allows the construction of slender structural elements, however we won’t be able to know how much the ductility of the structure in front of a seismic event will improve. Therefore, the reason of this study is to analyze the dynamic response of a tall building with different sections and resistance to the compression of its structural elements. The aim of this study is to obtain the curve of capacity and the point of seismic performance of each structural model.
Analysis of surface treatment of ASTM A516 Grade 70 using Salt spray method
Authors: Ali Khan Muhammad , Shah Aqueel , Husain Imran Jaffery Syed , Khan Mushtaq , Rasheed Khan Adnan 
Published: November 2019

Abstract
Conversion coating is an effective way to safeguard against corrosion. It is performed on a number of materials inhibiting the surface layer to corrosive attack. In this work surface engineering is carried out on test material ASTM A 516 Grade 70 which is widely used for constructional purposes. During the passivation process samples were given a hot alkaline oxide bath in sodium hydroxide and sodium nitrate. The corrosion resistance was then analyzed using advanced testing procedures. Salt spray test was used as a yard stick in making a comparative analysis of different samples including unpassivated samples, passivated samples and passivated samples with prior surface treatment. Results have shown that mechanical surface treatment improves material life by 3% whereas passivation with prior surface treatment can increase life by 18%.