Plastic Layer Research Articles

Выражение Марковско-Ичерской зоны дислокаций Непско-Батуобинской антеклизы в геологическом строении района Дулисьминского НГКМ

In the Nepa-Botuoba anteclise of the Siberian Platform, the Sosninsky swell-like fold-thrust structure is described that was formed, presumably, since the Late Devonian – Early Carboniferous under conditions of episodic displaying of significant tangential stresses from the southeast – i.e. from the structural heterogeneity of the Baikal-Patom highlands, which has formed in the Late Riphean. The effect of shear deformations occurred also. It is shown that tectonic displacements that were recognized along thick plastic layers of salt, caused a significant difference in the geological structure of the deformed lower-middle (supra-salt and saline) and undeformed lower (sub-salt) structural complexes of the Dulisma oil and gas condensate field.

Study on elastohydrodynamic lubrication performance of double-layer composite water-lubricated bearings

Double-layer composite water-lubricated bearing is a new type of water-lubricated bearing which can integrate the good damping performance of low elastic under-layer bush and good tribological performance of plastic layer bush. This paper analyzes its elastohydrodynamic lubrication performance by fluid–structure interaction (FSI) method, and studies the effects of eccentricity ratio, rotational speed, elastic modulus distribution and thickness distribution of bearing bush on its lubrication performance. Results show that the lubrication performance of double-layer bearing is more like that of plastic bearing. As rotational speed and eccentricity ratio increase, the maximum water film pressure, the load carrying capacity and the maximum bush deformation increase significantly. As the elastic modulus of the low elastic under-layer bush decreases, the total bush deformation increases significantly, but the load carrying capacity decreases slightly. The bush thickness distribution influences the deformation distribution of both low elastic under-layer bush and plastic layer bush, but have little impact on the total bush deformation and bearing lubrication performance.

English

A co-flow pilot filter with a packing support material (coated jujube seeds) was constructed and tested for the biological removal of iron from Senegalese groundwater. Indeed, it is a PVC tube with an internal diameter of 40 mm and a height of 90 cm. The performance of the filter was tested at a constant hydraulic head of 261.67 m3/m2 per day while the iron feed concentrations varied between 0.5-1, 0.5-1.5 and 0.5-2 mg/L, respectively. Coated jujube seeds, covered with a plastic layer and a biofilm containing microorganisms, were used as the filter material. The iron removal was carried out in a single stage, for which a period of two months was required for the maturation of the bed. In optimal working conditions (QL = 8.11 L/h; pH = 9.5; [Fe2+]0 = 2 mg/L; P = 1.013 bar and T = 25±1° C; Redox potential = 300 mV), an operating cycle time of 1 day has proven to be sufficient for the filter bed backwash operation. The results show that the biological treatment gives reduction percentages of 39.3, 48.76 and 67.23%, respectively for the boreholes of Pout Kirène (PK2), Pout Sud (PS5) and Koungheul (KK5).   Key words:  Biofilm, continuous test, biological oxidation, iron removal, column, doped water.

Intensification of stress state at deformation site under local action of a deformation tool

This paper discusses the development of a new procedure for finishing and hardening treatment by changing the kinematics of a deformation tool having a double-radius shape of the profile of the working surface, along with the determination of the stress-strain state in the site of elastic-plastic deformation and residual stresses in the hardened zone of the surface layer. The SOLIDWORKS 2018 software for 3D design and the ANSYS Work-bench 19.1 soft-ware using the finite element method were used to build a mathematical model of local loading. The temporary and residual stresses, the strain state in the loading zone, the depth of the plastic layer and the maximum value of the relative plastic deformation under various loading procedures of the working tool were determined. It was established that, at the reversible rotation of a double-radius roller, the values of temporary stresses are over 15% higher compared to those during static hardening, while the residual stresses are 5.7% higher. With the reversible rotation of the double-radius roll-er, the value of the maximum strain intensity becomes 2.11 times higher than that during static hardening. The intensity of the maximum residual stresses during the reverse rotation of the double-radius roller occurs at a depth 3 times greater than the indentation of the double-radius roller, rather than on the surface of the sample. The results of computer model-ling and numerical calculations indicate that the procedure of reversible rotation of a toroidal double-radius roller has the greatest influence on the intensity of the stress state in the deformation site, while the procedure of static hardening by a single-radius roller has the least impact. The obtained results suggest that the proposed technological process of surface plastic deformation based on the reversible rotation of the working tool will allow the radial tension to be reduced while maintaining the high quality of the surface layer of machine parts.

CALCULATION AND EXPERIMENTAL JUSTIFICATION OF DESIGN AND TECHNOLOGICAL SO-LUTIONS OF POWER HYDRAULIC CYLINDER ELEMENTS

The paper describes studies of the stress-strain state of power hydraulic cylinders elements. Geometric dimensions of casing and properties of materials are chosen as varied parameters. The controlled values are the levels of stresses and displacements. The criteria are weight, strength and rigidity. These characteristics determine the technical characteristics of power hydraulic cylinders. Dependences of criterion characteristics on varied parameters are established. On this basis, recommendations for substantiation of design and technological solutions of power hydraulic cylinders elements are developed. This made it possible to develop a project and technology for the manufacture of power cylinders with low material consumption. In addition, increased efficiency is provided due to the use of antifriction coating on the inner surface of cylinder. The stress level in the main material of cylinder body is limited. The strength of the area of the brazed joint material and the plastic lining layer is also ensured. A special configuration of the sealing ring is used to reduce the level of losses in the movable connection of the piston with the hydraulic cylinder body. At the same time radial displacements of the cylinder body provide acceptable contact of the moving and fixed parts of the hydraulic cylinder. In general, balanced design and technological solutions of power hydraulic cylinders elements are substantiated. They provide high technical characteristics of power hydraulic cylinders. It also increases the technological level of their production and reduces the total cost. Power hydraulic cylinders with reasonable parameters are used in the elements of technological systems. Keywords: hydraulic cylinder; finite element method; stress-strain state; computational-experimental justification

Ultrasonic interference and critical attenuation in metal-plastic bilayer laminates

The resonance of ultrasonic waves in a metal-plastic bilayer laminate placed in an infinite medium is theoretically investigated, and critical attenuation is shown to occur under specific conditions. The bilayer laminate is subjected to normal wave incidence from the side of the plastic layer. Based on a linear viscoelastic model, the amplitude of the reflection spectrum for the laminate is formulated to obtain the exact results for wave resonance and critical attenuation by numerical calculations. Furthermore, the approximate formulae for the conditions of the resonance and critical attenuation are derived explicitly by Taylor expansions with respect to the loss factor of the plastic. As a result, the exact solution shows that the resonance frequencies of the plastic layer slightly increase with increasing loss factor. Their variation with the loss factor agrees well with the second-order approximation result but is insignificant in the cases of common plastics with relatively low loss factors. The exact results also show that the amplitude at each order resonance depends on the loss factor and has a minimum at a critical loss factor. The obtained critical loss factor decreases with increasing resonance order and is well reproduced by the zeroth-order approximation. Experiments are performed on two types of metal-plastic bonded laminates, demonstrating that the measured reflection spectra are in good agreement with the theoretical predictions. In particular, the amplitude of the measured reflection spectrum decreases significantly at a resonance frequency, which is theoretically predicted to satisfy the critical attenuation condition.

The Influence of Coal Tar Pitches on Thermal Behaviour of a High-Volatile Bituminous Polish Coal.

The influence of three coal tar pitches (CTPs), having softening points at 86, 94, and 103 °C, on the thermal behaviour of a defrosted high-volatile coal during co-carbonization and co-pyrolysis was studied. The following research techniques were used: X-raying of the coked charge, TG/FT-IR, ATR and UV spectroscopies, extraction, SEM, STEM, and XRD. It was determined that CTP additives change the structure of the coal plastic layer, the thickness of its zones, and the ordering degree of the structure of semi-cokes to a different extent and independently from their softening points. The softening points of CTPs do not influence the composition and yield of volatile products emitted from blends with pitch as well as the composition, structural-chemical parameters, and topological structure of material extracted from coal blends. It is suggested that such a lack of existence of any correlation between the softening points of CTPs and the degree of their influence on the thermal behaviour of coal was caused by the presence of the atoms of metals (Fe and Zn) in the CTPs. These atoms change the course of the carbonization of the CTPs themselves and their influence on organic substance of coal in blends with CTPs.

Investigation on the interaction between corrosion and wear of U68CuCr rail steel with different corrosion periods

The interaction between corrosion and wear of U68CuCr rail steel was investigated. The samples were alternately subjected to the neutral salt spray tests with different corrosion periods (6, 24 and 48 h) and rolling friction wear test for 4 h. The corrosion and wear rates after the corrosion test and wear test were measured, respectively. The surface morphologies of the rail samples after the corrosion test and wear test, and the subsurface morphologies of the rail samples after the last test were observed. The results show that compared to the samples without corrosion, the damage degree of the corroded samples after wear tests became severer, and the wear mass loss and wear rate increased with the number of corrosion-wear cycle. In addition, rolling contact fatigue cracks initiated and propagated at a high angle and the structure of sample surface became unstable after corrosion, leading to easy spalling during the following wear tests compared to the only wear tests without corrosion. Moreover, the plastic deformation layer was destroyed by corrosion and the area of wear pits increased after the interaction test. Therefore, wear was accelerated by corrosion, and the longer is the corrosion period, the more severe is the wear degree. Additionally, regarding to the effect of wear on corrosion, corrosion was accelerated by wear. This is attributed to the facts that (1) the wear pits and delamination on the worn samples provided favorable locations for the deposition of the salt spray solution during the corrosion, and (2) the subsurface and matrix were corroded along rolling contact fatigue cracks to increase the corrosion rate during the corrosion test after wear. This work provides a foundation to the further investigation on the interaction between corrosion and wear of steels.

Response of carbon/PEEK automotive driveshafts with/without an inner isotropic layer at high temperature considering temperature-dependent material properties

Lightweight fibre-reinforced thermoplastic (FRTP) driveshafts are ideal for automotive applications. In this work, material and buckling failures of FRTP driveshafts subjected to torsion at elevated temperature are analysed by finite element modelling. Critical speed at increasing temperature is also quantified. The driveshafts comprise unidirectional carbon/polyetheretherketone (PEEK) layers with/without an inner layer of aluminium or unreinforced plastic. Temperature-dependent material properties are considered. The results demonstrate achievable performance of the fully carbon/PEEK and hybrid driveshafts, which are compared with traditional alloy counterparts. The carbon/PEEK shaft exhibits marked temperature sensitivity but satisfies the design requirements at high temperature with significant weight reduction. A hybrid shaft composed of carbon/PEEK layers over-wrapped onto an aluminium tube provides a compromise in terms of superior buckling resistance and critical speed but reduced material failure safety factor. Utilising a thick layer of unreinforced plastic to reduce fibre volume may only be suitable for low-temperature, low-speed applications.

Hydrogen Recovery from Waste Aluminum–Plastic Composites Treated with Alkaline Solution

An alternative solution to the problem of aluminum-plastic multilayer waste utilization was suggested. The process can be used for hydrogen generation and layer separation. Three different sorts of aluminum-plastic sandwich materials were treated with an alkali solution. In the temperature range of 50-70 °C, for tablet blisters of polyvinylchloride and aluminum (14.8 wt.%), the latter thoroughly reacted in 15-30 min. For sheets of paper, polyethylene, and aluminum (20 wt.%), full hydrogen 'recovery' from reacted aluminum component took 3-8 min. From the lids of polyethylene terephthalate, aluminum (60 wt.%), and painted polyethylene with perforations, the aluminum was consumed after 45-105 min. The effect of perforations was the reduction of the process duration from nearly 90 min for the lids with no perforations to nearly 45 min for the perforated ones (at 70 °C). Perforations provided better contact between the aluminum foil, isolated between the plastic layers, and the alkali solution. Hydrogen bubbles originating near those perforations provided foil separation from the upper painted plastic layer by creating gas gaps between them. The remaining components of the composite multilayer materials were separated and ready for further recycling.

Effect of surface severe plastic deformation on microstructure and hardness of Al alloy sheet with enhanced precipitation

The effect of severe plastic deformation on microstructure and hardness of 7075 aluminum alloy sheet presented different results from that of thick samples in previous study. Grains were not refined obviously, and precipitation phases MgZn2 were massively dissolved in the matrix in the region close to the surface. Varied density of dislocations were produced at different depths. The depth of severe plastic deformation layer was 40–70 μm, while the affected depth of hardness was much deeper. The maximum hardness enhancement, 16% increase compared to the core hardness, appeared at about 150–250 μm below surface. The hardness change depended on the competition between the roles of precipitation dissolution and dislocation multiplication.

Current trends in architecture at the right typological objects?

Global transformational processes are taking place in the modern world, covering and creating the material environment of a person, capturing the worldview of a person, philosophy, methodology, culture, science, and education.
 Social transformations, scientific, technical, and cultural progress, the way of life and way of life of a person, regional, cultural-historical, and natural conditions - everything finds expression in architecture, which is understood broadly - from urban planning systems to individual buildings and their details, from the worldview of a person to creative thinking, ego culture, knowledge, education. The research methodology is presented in library form and uses articles, and descriptions of the bureaus themselves and the architects of the respective websites in this study. The text presented here quantitatively shows the modern architecture of the world in different typological aspects and different directions. The results indicate that despite the different styles, there is a common direction of development of architecture in the layer of ecology and plasticity in different continents. Most often, all buildings are created in such a way that they are noticed and surprised. Modern architecture was formed in contrast with giving value to a person and his emotions in various aspects of his life. This applies to both cultural objects (museums) and sacred and utilitarian ones.

To the issue of forecasting the main parameters of carbons’ quality based on the vector simulation

During the prospecting the quality parameters, except for ash content, are specified by core samples and laboratory methods (geological sampling). Nevertheless, while prospecting the receipt of the representative sample with all its specified parameters being identical to the parameters of the carbon layer is difficult because of partial core recovery, its choking, etc. So, it is highly necessary to specify and to forecast the parameters of carbons’ quality by “indirect” methods which depend on sample representativeness. According to the experience that we have in specifying ash content by the data of the geophysical bore-hole logging (GBL), it is the geophysical sampling that meets this requirement. However, the deterrent of the use of the GBL data for specifying and forecasting of carbons’ quality parameters is the necessity of taking into consideration of a great number of factors (genetic and epigenetic ones) which can not be analyzed using the current mathematical methods. Only the vector simulation solved this task and helped to use the results of geophysical bore-hole logging for forecasting the parameters of carbons’ quality in full measure. The vector simulation will allow to enhance reliability and informativity while forecasting the main parameters of carbons’ quality in the rock mass according to the GBL data at the stage of geological exploration. While systematizing the geological and geophysical information the developed mathematical model, presented by structural vectors of system’s transient states, will enable to take into account some genetic and epigenetic factors in total. These factors influence the reliability of forecasting about such main parameters of the carbons’ quality as ash state, yield of volatile matters, moisture of analysis sample, thickness of plastic layer in the layers where geological sampling is not conditioning.

Simulation of water film formation during the 2018 Sulawesi earthquake, Indonesia

The water film effect is considered a key factor in triggering large-scale flowslides on gently sloping terrain in highly stratified, liquefiable sandy soils during the 2018 Sulawesi earthquake in Indonesia. The mechanism of water film formation under multiple less permeable soil layers (capping layers) with different plasticity characteristics is evaluated using one-dimensional (1D) soil model tests under impact loading and their 1D response analysis. As observed, a water film can form under both plastic and non-plastic capping layers under the influence of the impact load. The influence of the number of capping layers, as well as their plasticity, on water film formation and the dissipation of excess pore water pressure is evaluated. In addition, the resulting vertical and lateral deformation of the soil layers, together with the stresses generated under sinusoidal loading, inducing a water film effect are studied. From the results, it can be concluded that the configuration and the plasticity of the capping layer, which controls its permeability characteristics, have a significant influence on the stability of the water film. Moreover, the water film effect plays a key role in, if not being completely responsible for, triggering flowslides by forming a low-friction interface under the capping layer.

Effect of material positioning on Si-rich TIG welded joints of AA6082 and AA8011 by friction stir processing

The TIG-welded specimens were friction stir processed (FSPed) to analyze the impact material positioning of the base metals AA8011 and AA6082. The tests included the energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction, microstructure, hardness, tensile test and fracture surface analysis. The mean grain size of 24.83 µm was obtained for the TIG welded joint, 8.68 µm for the FSPed joint with AA6082 alloy on the advancing side (A.S), while 11.14 µm was obtained when the AA8011 was positioned on the A.S. In the TIG + FSPed zone, an intricate vortex flow pattern could be seen. The extremely superplastic flow of plasticized material is seen in the mixed flow zone, which results in a tumultuous intercalation pattern. In situ extrusions of different alloys and severe plastic, deformation was induced by stirring tool action. Lamellae structure was generated by moving the plasticized material layer by layer. In this zone, vigorous mixing and penetration of A6082 and AA8011 were observed. The maximum tensile strength and strain rate of the TIG weldment showed a significant increase after friction stir processing from 83.83 MPa with a strain rate of 23.79% to 90.09 MPa with a tensile strain of 28.04. However, evaluating the FSPed joints, the AA8011-AA6082 specimen had better tensile properties. Moreover, the fracture surface analysis correlated with the tensile tests. The FSPed AA6082-AA8011 joint showed a higher hardness than the AA8011-AA6082 one.

Grinding Temperature and Surface Integrity of Quenched Automotive Transmission Gear during the Form Grinding Process.

Grinding burn is an undesired defect in gear machining, and a white layer is an indication of severe burn that is detrimental to gear surface performance. In this work, the influence of grinding parameters on the thickness of the white layer during form grinding of quenched transmission gear was investigated, and the microstructure evolution and mechanism of severe burn formation were analyzed. The grinding temperature increased with the grinding depth and grinding speed, with the highest level of ~290 °C. The thickness of the white layer exceeded 100 μm when the grinding depth was 0.03 mm, and the top layer was a plastic deformation layer followed by a fine-grained martensite layer. Coarse-grained acicular martensite was found at the interface between the white layer and softened dark layer. The mechanical effect and thermal softening mainly contributed to the formation of white layer stratification. The ground surface topography showed several scratches and typical grooves; when grinding depth increased to 0.03 mm, the grinding surface roughness Sa was relatively high and reached up to ~0.60 μm, mainly owing to severe plastic deformation under grinding wheel extrusion and the thermal effect.

Self-Cleaning Trocars/Laparoscopic Port Add-on for Surgical Camera Lens

<h3>Study Objective</h3> During laparoscopic surgeries, the camera is visually impaired by blood, debris, and condensation. The process of cleaning includes removing the laparoscope out of the patient and then using cloth and/or lens defogging solution. Thus, there is a need for a device that will clean the camera without removing it from the patient to decrease surgical time, risk of contamination, and cost. <h3>Design</h3> We have developed a prototype of a disposable lens-cleaning compartment that is attached onto a disposable trocar to allow surgeons to clean the lens without removing the laparoscope from the patient's body. The cleaning compartment is made of three layers of plastic - upper, lower, iris diaphragm covered with synthetic cleaning material, and O rings on either side. The cleaning compartment will sit between the cap and the hollow tube of the trocar. This device will clean the lens by having the surgeon use a back-and-forth motion onto the compartment until the lens has visibility <h3>Setting</h3> N/A. <h3>Patients or Participants</h3> N/A. <h3>Interventions</h3> N/A. <h3>Measurements and Main Results</h3> Benchtop model of glass lens were clouded with egg, chocolate syrup, .25% agar and 1x DPBS saline (control) and cleaned with synthetic material for five full rotation of the laparoscope. Clarity was quantified through image J by filtering for black and white ratio. A two-way ANOVA showed significant differences with solution, time, and the interaction of the two. Solidwork stress simulation demonstrate that the device can withstand around 270N/60 lbs of force before breakage. Compartment was assessed with and without O rings and airtightness was noted with the use of O rings. <h3>Conclusion</h3> By adding a cleaning compartment to pre-existing trocars, laparoscopic surgery time will decrease as there is no need to remove the laparoscope from the patient. Future work would include testing product within the OR to further validate the product design to meet surgeons' need.

Residual stress evolution and surface morphology in grinding of hardened steel following carburizing and quenching processes

AbstractIn this paper, the residual stress evolution and surface morphology of quenched 20Cr2Ni4A steel after surface grinding with alumina grinding wheel was investigated. The initial compressive residual stress in the surface layer evolved into tensile stress after grinding. Since thermal stress was the dominated factor, the effect of grinding speed and grinding depth showed significant effects on the level of residual stress. The tensile stress on the ground surface increased by more than 50 % when grinding speed increased from 26 m/s to 34 m/s at the feed speed of 0.19 m/s to 0.26 m/s. The increase of grinding depth from 0.02 mm to 0.03 mm resulted in the increase rate of tensile stress varying between 54 % and 85 % at specific feed speed and grinding speed. Due to the extrusion and cutting of abrasive particles, plastic deformation and grooves were found on the machined surface. The influence of grinding heat and grinding force caused a plastic deformation layer and grinding burn layer within 20 μm.

Effect of surface roughness on low-cycle fatigue behaviors of 316LN stainless steel in borated and lithiated high-temperature pressurized water

Low-cycle fatigue behaviors of 316LN stainless steel with three surface roughness were investigated in high-temperature pressurized water at different strain rates (0.001−0.04%/s) under strain amplitude of 0.3%. More significant reduction of fatigue life was found for samples with higher roughness. The environmental fatigue effects with different surface roughness were strain rate dependent and the weakened effect at low strain rates was related to the plastic deformation layers which enhanced the diffusion of Cr and played an inhibiting role on fatigue crack growth. Besides, the fatigue damage mechanisms for polished and rough samples are discussed.

Ability of benthic oligochaetes to bury microplastics in aquatic bottom sediments

Benthic organisms, including freshwater oligochaetes Tubificidae, contribute to redistribution of microplastics (MPs) in aquatic bottom sediments. In this work quantitative data was obtained in the model experiment characterizing the rate of polypropylene (PP) microparticle burial under the action of Tubifex tubifex worms in silty freshwater bottom sediments. The burial of PP was fixed by the dynamics of the plastic layer sinking from the surface to the bottom in a microcosm over the 150 day period. The average rate of microplastic (MP) deposition in presence of worms was 4.14 ± 1.29 cm year−1 compared to 0.73 cm year−1 under control conditions. Bioturbation due to the motion of worms in the sediments and their respiratory movements is the leading factor in the burial of MP particles. The study confirmed that bottom sediments accumulate deposited MPs, including those with the participation of macrozoobenthos organisms. Tubificidae worms, thus, may simultaneously enhance entraining particles inside the sediments and reduce the “load” on the macrofauna feeding on their surface.