bluuebunny/crossref_metadata_2025_split huggingface dataset:
Finite element modeling and durability evaluation for rubber pad forming process
Authors: Park J , Kim Y , Yoon J W , So H , Lee J , Ko S 
Published: November 2019

Abstract
Elastomer (or rubber pad) forming is a dieless forming process. The forming process has several advantages compared to general press forming process in terms of tool cost and scratch problem. However, when the elastomer is subjected to severe deformation during forming process, it can result in an expensive cost for the replacements of elastomer. Therefore, it is necessary to evaluate accurate tool life. In this study, the FE analysis was conducted for the rubber pad forming process and the fatigue life evaluation of the elastomer tool was investigated numerically using the reference experimental data. For the FE analysis, uniaxial and equibiaxial tension tests of natural rubber 50 were carried out in order to obtain the mechanical material properties of the elastomer. The hyperelastic behavior of the elastomer was characterized using Ogden model. The elastomer forming process was modeled using a commercial software LS-DYNA 3D. Two important factors of FE modeling were to calibrate the simulation conditions and to obtain the target product shape with a preformed elastomer. With the result of FE analysis, a durability of the elastomer was conducted focusing on fatigue life, because the elastomer is applied for repeated loadings during the forming process. Unlike general fatigue analysis, the fatigue life of the elastomer is predicted with respect to the strain measures due to Mullins effect. Furthermore, the Polar Effective Plastic Strain (PEPS) diagram [6] considering the strain path changes was used to check the failure of the blank during the forming process.
A new approach for advanced plasticity and fracture modelling
Authors: Park N , Stoughton T B , Yoon J W 
Published: November 2019

Abstract
A solution to the challenge of modelling the general yielding behaviour including fracture initiation is proposed based on non-associated flow rule. A decoupled formulation with employment of a Lagrangian interpolation function is established to develop a general fracture criterion that considers the mutual effect of the material anisotropy, the strain rate, and the temperature on the onset of fracture. An advanced constitutive law is also developed to accurately describe the evolution of the anisotropy/asymmetry-induced distortional yielding behaviour, using neither any interpolation nor optimization techniques for the calibration of the yield surface. The proposed models are successfully applied to various types of metallic materials to validate their noticeable flexibility and applicability in describing the general material behaviour during various forming processes.
Spring-Back Analysis Method Considering the Die Deformation Due to the Stamping Pressure of the Ultra-High Strength Steel
Authors: Bae Gihyun , Song Junghan 
Published: November 2019

Abstract
This paper proposes a spring-back analysis method for investigating the effect of the stamping pressure on the final shape of a B-pillar outer panel manufactured with the ultra-high strength steel. The conventional sheet metal forming simulation of the B-pillar outer panel was conducted with rigid tool surfaces and a deformable blank of CR1180TRIP. Press and die structure was modelled with three dimensional tetrahedral solid elements for the structural analysis. The stamping pressure obtained from the forming simulation was mapped to the tool surfaces in the tool structure model. From the implicit structural analysis, the deformation amount of the press and die structure was investigated quantitatively. The structural analysis method was verified by comparing the total stamping force of rigid surface model and deformable tool structure model. Finally, the conventional sheet metal forming simulation with modified rigid tool surfaces was conducted to investigate the effect of the tool deformation on spring-back. The simulation result shows that the deformation amount due to the stamping pressure can have significant effect on the final product shape.
A robust experimental technique to determine the strain to fracture for plane strain tension
Authors: Roth C C , Grolleau V , Mohr D 
Published: November 2019

Abstract
The stress state of plane strain tension plays a crucial role in many forming and crash applications. Under plane stress conditions (in thickness direction), most micromechanical and phenomenological models predict a minimum in ductility for a plane strain tension loading (in the plane of the sheet). When looking at Forming Limit Diagrams (FLD) or at modern stress state dependent fracture initiation models, a “plane strain ductility valley” exists between uniaxial and equi-biaxial tension. Given that the ductility reaches a minimum for plane strain tension, the reliable measurement of the strain to fracture for plane strain tension is particularly crucial when calibrating modern fracture initiation models. Many experimental techniques have been proposed in the past, but a standardized universal experimental technique for plane strain tension testing is still missing to date. It is the goal of the present work to develop a robust experimental technique for determining the strain to fracture for plane strain tension. Emphasis is placed on finding a technique that is universally applicable i.e. that provides reliable results irrespective of the material thickness or ductility. In addition, it should be easily automatized in order to be included in up-to-date test protocol dedicated to the prediction of the behavior from large database analysis. The experiments are designed such that the material is subject to proportional loading, i.e. the stress state remains constant throughout the entire loading history until fracture initiates. After identifying a suitable specimen geometry through finite element simulations, experiments are performed on specimens extracted from aluminum alloys and steels sheets. The experimental campaign includes three different types of plane strain tension experiments (flat notched tension, V-bending and the newly-proposed stretch-bending of mini-Nakazima specimens) to elucidate their differences and limitations, and to demonstrate that the newly-proposed technique is the only one that yields meaningful results for all three materials.
Numerical evaluation of mechanical performance for self-piercing riveted fiber-reinforced plastic and metal sheets
Authors: Noh W , Park K Y , Kim C , Lee M G , Jung C Y , Song J H 
Published: November 2019

Abstract
Finite element analysis is presented to evaluate the mechanical performance of self-piercing riveted fiber-reinforced plastic and metal sheets. The mechanical properties of the rivet and the sheets subjected to joining are considered for reliable simulation. Yielding and hardening behaviour of the rivet was inversely characterized by a coupled experimental-numerical analysis of a compression test, while those of the sheets were deduced by directional tensile test as usual. Fracture criterion was characterized and considered only in the sheets. The geometric features of the die and the rivet were also quantitatively measured and applied to the simulation as the boundary conditions. Consecutive simulations of riveting process and tensile shear test were carried out, which leads to determining sensitivity of peak load to characteristic rivet-joining features such as interlock and bottom thickness.
Processing of videos of the fatigue cracks propagation in the rotor blades of the helicopter
Authors: Kurokhtin V Yu 
Published: November 2019

Abstract
The article describes the processing of videos of growing fatigue cracks in the main rotor blades of a helicopter, which are formed during their fatigue tests on the stand. A specially created computer program allows to determine the geometrical parameters of a crack based on video recording (length, width, extreme points, center of gravity). Each frame of the video is binarized, after which a binary matrix is created on its basis, which is subject to element-by-element processing. The obtained data are presented in the form of a graph showing the dependence of the crack growth rate on the time of its growth. The graph is traced in the Mathcad program, as a result, two data vectors are created — the time and crack growth rate, which undergo an interpolation procedure with the construction of a third-degree polynomial. According to the results of the integration of the polynomial, the critical length of the crack is determined, after reaching which its rapid growth begins.
Research on the technology of paste boronizing for H13 die steel
Authors: Yan-Wei Zhang , Quan Zhen , Lygdenov Burial , Guriev A M , Shun-Qi Mei 
Published: November 2019

AbstractIn this paper, the boronizing effect of H13 hot work die steel is studied. The experiment is carried out to compare the boronizing effect of H13 steel at 850 °C, 900 °C and 950 °C. The heating time is set to 4 hours. The experimental results indicate that the temperature at 950 °C is suitable for boronizing of H13 steel. At 950 °C the boronized layer is more tightly bonded to the matrix, and the depth of the layer is deeper than at 850 °C and 900 °C. The hardness of the layer at 950 °C is better than at 850 °C and 900 °C in terms of the hardness of the layer. Therefore, 950 °C is a suitable temperature for boronizing the H13 hot work die steel.
Study on the bending property of shirt sleeve slits
Authors: Yi-Chuang Gu , Shun-Qi Mei 
Published: November 2019

Abstract
Shirts are the clothing products that people need in all seasons. The folding effect of shirt sleeves directly affects the quality of the sleeves. In this paper by controlling the fabric of the shirt, the folding pressure and the additional pressure time, the fold recovery performance of the sleeves are studied from three aspects: bending stiffness, wrinkle recovery angle and bending recovery force. The experimental results show that the greater the areal density of the fabric is, the greater the restoring force is, the less likely the sleeves are folded. Under operation time of 5 minutes, the pressure of 30 N, 40 N, 50 N is applied to the wool fabric and the polyester fabric respectively, the restoring force was 1.0 cN, 0.75 cN, 0.5 cN and 1.2 cN, 0.8 cN, 0.6 cN respectively. At the same time the experimental results show that, the greater the additional pressure is, the smaller the resilience is, and the better the folding effect of the sleeves is. The research in this paper provides a theoretical basis for the actual production of the folding of the shirt sleeves and improves production efficiency by controlling the relationship between negative pressure and negative pressure time.
Complex saturation of corrosion resistant steels AISI430 and AISI303 with boron and carbon
Authors: Shunqi Mei , Guriev A M , Ivanov S G , Guriev M A , Lygdenov B D 
Published: November 2019

Abstract
Studies have been conducted on the effect of the degree of doping with chromium and nickel on the formation of boride coatings on steels AISI430 and AISI303. The saturation was carried out in a SNOL-type chamber furnace equipped with a PID controller from a powder saturating medium in an unsealed crucible. A mixture of boron carbide powders (70 wt. %), potassium tetraborate KBF4 (7 wt. %) and graphite – up to 100 % was used as a saturating medium. The process temperature was 900 ºC, the saturation time was 2.5 hours. Upon completion of the high-temperature exposure, the crucibles were removed from the furnace and cooled in air to the 50–60 ºC temperature. Diffusion coatings with a total thickness of 120 μm were formed on steel AISI430 and 75–85 μm on steel AISI303. The thickness of the boride layer for both steels was 45–50 µm.
Study on physical properties of dispersed silica
Authors: Tserenjav E , Jigmeddorj V , Lygdenov B D , Bayraa U , Tsevelmaa D D 
Published: November 2019

Abstract
The paper deals with the physical properties of colloidal silica dispersed system such as distribution width (Q
x, %) and density (q
x, %) defined by photon cross correlation spectroscopy (PCCS) at an average size of 17.06 nm for D
50 % and the area of specific surface of 349.96 m2 cm−3 depending on molar (R
m2) optimal ratio of silica stone mineral to alkali ash powder. The change of crystal structure to amorphous state was determined by X-ray diffraction analysis. The results of their kinematic viscosity, liquid density, UV light adsorption inspections show possibility to produce the colloidal silica by using the wetting and ultrasonic vibration method for that fusible alloy.
3D aerosol printing as method to obtain low-temperature ceramic layers of printed circuit boards
Authors: Ivanov A A , Chermoshentseva A S 
Published: November 2019

Abstract
A method for the synthesis of the polyaluminosilicates (PAS) with the macromolecules of dendrimer morphology has been developed. A quantum-chemical assessment of thermodynamically possible mechanisms to develop the populations of short-chain aluminosilicates (nuclei of dendrimer macromolecules) has been carried out followed by the domains generation from the dendrimer assemblies capable to contain up to 80 % wt of the dispersed filler particles into their interdomain spaces by means of the GAUSSIAN B3LYP/6-31G (d) software package. A quantitative calculation of the parameters determining the composition of PAS macromolecules and the size of the dendrimer assemblies has been carried out. A method for the synthesis of monomeric precursor-powder has been developed. A new low-temperature ceramic composite material for 3D aerosol printing has been developed on the basis of the PAS and highly dispersed precursor-powder. The processes of 3D aerosol printing of the PAS filled with monomeric precursor-powder have been researched. An optimal method for aerosol generation has been chosen that does not affect the PAS supramolecular structure. The ceramic dielectric layers with high consumer properties have been obtained by means of 3D aerosol printing.
On improving the operational properties of metal-fluoroplastic plain bearings
Authors: Rogov V E , Baldanov A B 
Published: November 2019

Abstract
The analysis of metal-fluoroplastic materials was carried out. Domestic metal-fluoroplastic materials do not meet the requirements of regulatory and technical documentation adopted in domestic engineering. A review of patents on technologies for the production of metal fluoroplastic materials (MFM) was carried out. Promising methods for producing MFM have been identified. New methods can significantly increase the operational characteristics of fluoroplastic materials. For widespread use of metal-fluoroplastic plain bearings it is necessary to increase their performance. Reducing the linear wear parameter is possible by increasing the nominal area of the metal contact.
Design of rectangular sandwich panels with metal skins based on post-buckling state in compression and shear
Authors: Mitrofanov O V 
Published: November 2019

Abstract
Solutions of geometrically non-linear tasks concerning post-buckling behavior of sandwich panels with thin metal skins and lightweight filler loaded by compression and shear flows are shown. Based on obtained solutions methods of aircraft structures sandwich panels design based on post-buckling state with acceptable global buckling in case of ultimate loading are suggested.
Experimental study of continuous welded rails deformation under the effect of axial force
Authors: Novoseltsev P V , Bokhoeva L A 
Published: November 2019

Abstract
On the Russian railways there is a transition from conventional rail to a continuous welded rail track, however during its operation, occasional track disturbances occur due to internal stresses in the rails caused by the temperature and longitudinal stresses generated by passing rolling stock and creepage of the railway. Stresses can be tensile in winter and compressive in summer. They can reach dangerous values leading to rupture of the track at low temperatures and its ejection at high temperatures. To ensure traffic safety, it is necessary to develop a technology for monitoring stresses arising during operation. The authors created and obtained a patent for a device which made it possible to determine the generated stresses. Studies were carried out on welded rail behaviour and the dependence of displacements and stresses on the action of an external force was obtained.
Accounting for shear deformations with bending a round plate
Authors: Bokhoeva L A , Chermoshentseva A S 
Published: November 2019

Abstract
This paper presents a solution of the stability problem of a round plate taking into account the influence of shear deformations. The critical load of a round plate is determined taking into account shear deformations and without taking into account the shear deformations. The critical load taking into account the transverse shear with a local stability loss of a round plate is less than the critical load without taking into account the transverse shear. The inclusion of shear deformations in the study of the supercritical behavior of a round plate for isotropic materials does not have practical value, but it makes sense with extremely strong anisotropy of the elastic properties of the material.
On the results of integrated researches of the initial raw material and fenced glass structure with the application of modern physical and chemical methods
Authors: Anchiloev N N , Rogov V E 
Published: November 2019

Abstract
Studies have been conducted on the structures of the initial raw material and obtained on their basis foam glass of the “aluminosilicate rock –cullet – sodium hydroxide” systems with the use of X-ray and thermal analysis. The interrelation of the prescription-technological parameters and the physical and mechanical properties of the foam glass of the system “cullet – aluminosilicate rock – sodium hydroxide” has been established. Compositions of foam-forming mixtures have been developed, thus making it possible to obtain foam glass with the density from 412 to 1200 kg m−3 and strength from 2.0 to 16.1 MPa.
Thermal conductivity improvement of Al alloy with Nb nanopowder using SPS for transmission conductor
Authors: Ujah C O , Popoola A P , Popoola O M 
Published: November 2019

Abstract
Aluminium 1000 alloy has high purity and good electrical conductivity required for high power transmission conductors but lacks adequate thermal conductivity which induces sagging in service. To augment this deficiency, Nb nanopowder was incorporated into it as a reinforcement and consolidated with spark plasma sintering (SPS). The SPS was conducted with pre-optimized processing parameters of 630 °C, 30 MPa, 10 mine and 200 °C/min. The sintering was conducted in a vacuum with graphite die of 20 mm in diameter. Thereafter, the sintered samples were metallographically prepared and subjected to thermal conductivity testing. A laser flash analyzer was used to generate the thermal diffusivity of the samples. Then their thermal conductivities were computed. Results obtained showed that Al-4Nb had the highest thermal conductivity of 115. 95 ± 6.9 W/mK which represented 42% improvement. So, it follows that Al-Nb composite is a better replacement for monolithic Aluminium 1000 alloy in power transmission conductors with a potential property of low sag.
Numerical and experimental analysis of the rotor eccentric effect on the labyrinth seal
Authors: Mo Jintao , Yu Zhiwei , Luo Ying , Du Hua 
Published: November 2019

Abstract
Labyrinth seals are widely used in turbomachines. In this paper, a transit simulation method is introduced to model the relationship between the journal offset in Labyrinth seals and the system stability based on Fluent UDF. A special dynamic mesh method has been adopted to ensure fine mesh quality during the arbitrary motion of the journal. In each time step, the transient fluid seal force on the journal surface is obtained by the solving Navier-Stokes equations. Then the displacement of the journal in the next step can be numerically solved by the FEM model of the rotor system. For every transient time step, the computed fluid seal force and the rotor motion displacement were coupled by data exchange. The experiment is carried out in a steam turbine with a position adjustable labyrinth seal. The experimental results show that the amplitude of the vibration decreases after the change of the relative position between the journal and the labyrinth seals and the numerical results show that the locus of the journal under different labyrinth seal offsets has some half-frequency components. Both the simulation and the experiment validates that the relative position between the journal and the labyrinth seals can greatly affect the stability in the coupled rotor-seal system.
Heavy Object Lifting Platform to Correct Human Balance and Posture
Authors: Raymundo F , Quispe G , Raymundo-Ibañez C 
Published: November 2019

Abstract
This research document on technological development is aimed at workers in small companies, those that are developing well and soon to emerge as companies that will be positioned at the top of their labor sector. Starting from the problem at present with respect to the bad manipulation of loads it is arranged to solve the problem with established objectives to try to correct the corporal posture at the time of lifting an object with a machine that replaces the functions of the worker. The design and the solution was made based on the requirements of the worker, workers who have the need to load objects at a certain height, here the man-machine relationship, demands and desires that help to achieve the general objective are analyzed. In addition, it has the main function of this machine: to lift heavy objects of up to 150 kg of mass, this due to the implementation of a hydraulic piston in the lifting platform. The appropriate solution is an adaptation of a platform in the form of a truck forming an angle of 47.17 between the structure of the truck and the horizontal surface, this position is the most adequate so that the back does not suffer injuries during the handling of loads at work. The results give assurance that it is a machine of reliability and easy handling since it only requires an operator to control the objects and a flat position on the back without damaging the spine.
Controlled Trim-Blasting Model to Improve Stability and Reduce Vibrations at a Production Gallery of the San Ignacio de Morococha S.A.A. Mining Company
Authors: Camallanqui-Alborque C , Quispe G , Raymundo-Ibañez C 
Published: November 2019

Abstract
This paper presents a blasting method called controlled trim blasting, in which the rock mass of an unstable gallery where high levels of vibration have been detected is analyzed. This methodology comprises a drilling mesh with two-contour gallery assessment, producing its drilling machines and determining the type of explosive used and burden and spacing, which will be detonated after the internal blasting. Further, the internal blasting will possess its drilling machines, burden, spacing, and a second type of explosive. The separation of the gallery into smaller parts will improve the blasting, as verified in the recorded simulation. In addition, the rock-mass stability improves because the explosives used in the perimeter of the gallery are low-power with mild detonation pressure, which does not generate high levels of vibration. This is a practical and efficient method in areas where the rock mass is not good or there is a mixture of rock types.