Cylindrical Products Research Articles

Modelling and simulation of hot direct extrusion process for optimal product characteristics: Single and multi-response optimization approach

The study of eccentricity minimization in cylindrical products helps to reduce the mechanical vibrations and wear of related mechanical parts such as bearings, columns and gears which positively affects in maintenance costs savings and increasing production quality reliability. The main purpose of this paper is to investigate the effect of the eccentricity between the billet material and the die parts on the quality of the final product in the direct extrusion process. The input parameters to produce a cylindrical product shape are optimized in MINITAB based on Taguchi method and ANOVA. The selected material of the billet is the aluminium alloy AA2024, and the die material is Steel H13. The inputs parameters are the temperature, the die angle, the ram speed, and the presumed eccentricity. The finite element model of the process is simulated in DFORM-3D for providing the extrusion information such as the pressure, the effective stress and strain, the final product eccentricity, and the roundness error. The study is carried out on two cases of the presumed eccentricity in addition to a case of zero eccentricity. The single and multi-response optimizations are executed to obtain the optimum parameters for the minimum product eccentricity and roundness error.

Experimental study on the influence of brine concentration on the dissociation characteristics of methane hydrate

Brine stimulation is a common method for assisting depressurization to produce hydrate, which significantly improves the efficiency of hydrate production. In this work, to study the influence of brine concentration on the natural gas hydrate production process, a novel cylindrical hydrate production simulation experimental device was established, and investigations of hydrate dissociation experiments induced by depressurization in conjunction with brine injection were carried out. The effects of different brine concentrations on the gas production rate and heat transfer during production were studied. The distribution, flow, and concentration evolution of brine during hydrate production were analyzed. Brine injection can significantly enhance cumulative gas production during the depressurization stage, increase the sensible heat for hydrate dissociation, enhance heat transfer between the hydrate reservoir and the environment during the recovery process, and significantly improve the gas production rate of hydrate. The increase in the gas production rate caused by brine injection mainly occurs at the end of the depressurization stage and the beginning of the constant pressure stage. The injected brine is mainly located in the middle and upper areas of the reactor. In the bottom area of the reactor, the hydrate has higher saturation and longer dissociation time, which is slightly affected by the injected brine. A higher hydrate saturation is not beneficial to brine injection and does not promote hydrate dissociation. Additionally, in the experiments with brine injection, the resistance decreases more obviously during the depressurization stage due to more hydrate dissociation. The resistance also shows that in the bottom area of the reactor, there is a higher hydrate saturation and a lower brine effect on hydrate.

Structural Analysis and Optimization of Steel Pin on Cylindrical Head Suspension Porcelain Insulators

There is no essential difference in theory between the inner and outer insulating properties of cylindrical and conical head disc suspension porcelain insulators. Compared with a conical head porcelain insulator, a cylindrical head porcelain insulator is significantly lighter in weight, which can effectively reduce the mechanical load of the tower and wire; and it has better dispersion and adjustment capabilities for changes in material properties over time, so that the product is not subject to excessive and uneven stress over a long-term. In order to improve the mechanical performance of cylindrical head insulator products, this paper establishes a parameterized fine simulation model of the steel pin without changing the geometry of the insulator iron cap and porcelain body. The finite element method is used to calculate and analyze how the geometric parameters of the steel pin influence insulator mechanical properties, which can provide design reference for further product optimization.

FORMATION OF QUALITATIVE INDICATORS OF PRODUCTS BY ROLLING STAMPING PROCESSES

The influence of rolling stamping on the service characteristics of products is investigated in the work. Based on the analysis of deformation kinematics, stress-strain state, microstructure and evaluation of deformability of workpiece material, ways to increase geometric accuracy, vacuum tightness, electrolytic stability and mechanical characteristics of product material, as well as ways to improve the material of workpieces for their subsequent processing. The influence of active friction forces on the nature of the material flow during SHO was established, which contributed to the development of new processes that allow to bring the shape and dimensions of the workpiece as close as possible to the finished part. Thus accuracy of the sizes of details corresponds to 7-11th qualities of accuracy, and roughness of the processed surfaces makes Ra = 2,5… 0,63 microns. The process of reshaping the square billets into round ones by the method of SHO is effective, which increases the utilization factor of the metal and reduces the anisotropy of its mechanical properties. The characteristic of flat anisotropy λr, adopted in sheet metal stamping as a characteristic of the ability of the material to form scallops, decreases as a result of reshaping by 70-80%. The relative difference in yield strength in the plane of the sheet decreases from 0.10-0.15 to 0.03-0.05. The ultimate tensile strain increases by 8-10%, and the uniform uniform strain - by 5-8%. This improvement in the characteristics of the material reshaped by rolling blanks leads to the fact that when drawing cylindrical products, the value of scallops decreases by 2-2.5 times, and the value of the maximum degree of drawing increases by 10-15%. This reduces the relative difference in wall thickness along the perimeter of the elongated workpiece, and the change in wall thickness along its height becomes linear. Thus, the use of SHO processes significantly improves the quality characteristics of products.

KARAKTERISTIK KEBULATAN TERHADAP PARAMETER PROSES PEMBUBUTAN PADA MATERIAL ST 42 MENGGUNAKAN METODE TAGUCHI DAN ANOVA

This research is about the roundness characteristics of the turning process parameters on St 42 material using the Taguchi and ANOVA (Analysis of Variance) methods. A cylindrical product requires a good roundness value to ensure its quality. One of the factors that determine the quality of these products is the machining process parameters. In this study, optimization of the turning process parameters using the Taguchi and ANOVA methods was carried out on the roundness characteristics of the workpiece. The workpiece used is Steel St 42. The lathe used is the Krisbow Precision Gear Head Machine 410X1000MM. After data analysis using the Taguchi method, the parameters with the optimum roundness value of 7.385 µm were 510 rpm spindle rotation, 1mm depth of cut, and coolant opening valve. The results of the ANOVA analysis show the percent contribution of each parameter, respectively, as follows: spindle rotation 26.97%, depth of cut 24.82%, and coolant 38.63%.

딥러닝 비지도 학습기반 원통형 2차전지 결함 검출 방법

This paper proposes a defect detection method through unsupervised learning based on AI deep learning for surface defect inspection of cylindrical secondary battery products. The existing traditional vision processing methods face limitations in designing suitable vision processing algorithms according to product diversity, environmental changes, and various types of defects. The supervised learning-based defect detection method requires labor and cost to secure sufficient defective samples of all types. To overcome these limitations, we propose an unsupervised learning method that uses only good-quality learning data. In this paper, by designing an appropriate optical system and acquiring images from a camera, surface defects of secondary batteries could be detected through relatively small learning data and image pre-processing methods. The effectiveness of the proposed model was verified through an experiment.

Drawing of Square Blanks in a Cylindrical Die with Controlled Movement of the Edges

Plastic forming, in many cases, includes the drawing of hollow cylindrical products as the main operation. For the manufacture of such products, round blanks are used as semi-finished products. However, during the blank production from strips or tapes, their geometry causes a very significant metal loss. A very effective way to reduce metal loss is to replace round billets with square ones. The use of square blanks gives an additional increase in the height of the products. In this regard, the article investigates the drawing of a square blank into a cylindrical die. The research was carried out on the basis of the analysis of experimental work and computer modeling. According to the results of the research the rational ratios of the geometric dimensions of the tool and workpieces are found.

Cleaning substrates and subsequent deposition of coatings with coaxial magnetron discharge

The created experimental magnetron sputtering system allows preliminary cleaning of the substrate surface and subsequent deposition of coatings on long cylindrical products within a single system using a coaxial magnetron discharge at a working gas pressure of 150 mTorr. The coating discharge has reverse electrodes polarity relative to the cleaning discharge. A theoretical calculation of the discharge parameters has been carried out.

EXPERIMENTAL INVESTIGATION OF CYLINDRICAL FOOD PRODUCT DURING FORCED CONVECTION COOLING

The objective of this work is to study the transient heat transfer behavior during precooling of cylindrical food product at different air flow rates. Temperature measurement is carried out at the center of the specimen at different air flow rates (3.8, 4.0, 4.2 & 4.5 m/s). These temperature distributions are plotted with time. The terms of Fourier equation were evaluated and thermal diffusivity was plotted against the temperature variation during cooling of the cylindrical food product.Surface film conductance values is also calculated in present work, at different air flow rates. These values are effective values, which included the additional cooling effect due to moisture evaporation from the exposed product surface. Variation of Reynolds number and Nusselt number is also plotted with different air velocities and it is found that more favorable results of thermal conductivity and thermal diffusivity is obtain at 3.8 m/s. Which ultimately saves energy and provide optimum cooling for the specimen at the given air velocity.

An Example of Controlling the Obtained Characteristics of Technological Stress Distributions in a Layer-By-Layer Manufactured Product, Based on a Model of Additive Process Mechanics

Technological processes of layer-by-layer manufacturing of cylindrical products by the method of power winding of a thin tape on a sufficiently rigid circular base are considered. A characteristic factor for the processes under consideration is the creation of initial stresses in the elementary layers of additional material, which are sequentially included in the composition of the being formed product. It is assumed that the applied winding technology allows us to arbitrarily influence these stresses. This makes it possible to control the technological stresses developing in the resulting product. This paper is devoted to the formulation and solution of one of the problems of such control using current approaches of additive process mechanics. The simulation is performed in a quasi-static approximation within the limits of small elastic strains. A non-classical mechanical model of the process under study is proposed, and a mathematical formulation of the corresponding initial boundary value problem and its closed analytical solution are given. Based on the constructed solution, the regularities of the influence of the initial stress state of the attached material on the nature of the development of the contact pressure on the used base from the side of the material layer formed on it are studied. The problem of providing the required law of change in the value of this pressure in the process under consideration by setting the appropriate program for varying the initial stresses is formulated and solved. Corollaries of an applied nature are made.

Powder Forging of in Axial and Radial Direction Graded Components of TRIP-Matrix-Composite

Powder metallurgy is one way of producing complex, graded structures that could allow material systems to be produced with properties tailored to individual applications. However, powder metallurgy requires that the semi-finished products are very similar to the final component. It is much more economical to produce simple semi-finished products and then combine them by powder forging and simultaneous compaction than forming complex components with the desired graded structure. However, it is absolutely necessary that the graded structure of the semi-finished products is maintained during the forming process. In this study, pre-sintered cylindrical semi-finished products, consisting of axially graded as well as radially graded components, were produced by powder forging at 1100 °C. The microstructures, densities and mechanical properties of the final components were investigated to verify the effectiveness of the process route. It was observed that the components formed solid structures after compaction, in which the reinforcing ZrO2 particles were fully integrated into the transformation-induced plasticity steel matrix.

Analysis of the influence of the geometry of the input part of the matrix on the formation of the edge part of the cylindrical bill

The formation of an uneven geometry of the end part of cylindrical products is quite common after the implementation of drawing of sheet blanks. It occurs due to the imbalanced orientation of the crystallographic structure of the material, that is, due to the anisotropy of the mechanical properties. As different elements of the sheet bill have different speed of movement relative to the tool during the drawing, so-called scallops, or protrusions, appear. This causes a problem during the production, since it takes additional time and resources to bring the geometry of the products to the norm. Therefore, the actual task is to minimize this phenomenon. The article discusses an approach to eliminating or minimizing scallop formation by means of scientifically grounded selection of the geometry of the input part of the matrix. The influence of geometry parameters on the uneven geometry of products and their stress state is described.

PERANCANGAN MESIN EKSTRUSI UNTUK DAUR ULANG SAMPAH PLASTIK BERBENTUK SILINDER

Extrusion technology is one way that can be done to produce a product. The extruder machine is a tool that is quite simple but has its own uniqueness, the way this tool works is to insert raw materials which will be processed and then pushed out through a die in accordance with the desired shape. The purpose of this research is to design an extruder in order to produce a cylindrical product (filament), and to recycle waste into a product that has added value and economic value, so that it can be applied to society as an effort to reduce plastic waste. The research method used is development research with the determination of several variables, namely: control variables in the form of plastic material with the type of PET and HDPE, the independent variables are temperature and engine speed (rpm), and the dependent variable is the time needed to produce a product. The results obtained for the PET type plastic have the characteristics of fast liquid and runny, the results are discontinuous (discontinuous), brittle (brittle), for HDPE it has the characteristics of liquid and hard, continuous yield, the resulting surface looks rough with flexible plastic properties, strong and elastic, while for the mixture of PET and white HDPE, the characteristics are liquid, and continuous. This mixture of PET and HDPE has a long drying time of up to 1350 seconds.

Design and testing of CFRP sleeve for a high-speed permanent magnet synchronous motor with surface-mounted rotor

A high-speed (HS) permanent magnet (PM) synchronous motor (HSPMSM) with a carbon fiber-reinforced plastic (CFRP) protective sleeve in the surface-mounted rotor was explored in this study. In view of retaining the PMs at HS operations, the high-strength CFRP sleeve was designed on the basis of a process that could be summarized as follows. First, a multi-physics analysis of the rotor was conducted. The requirements to the CFRP sleeve were obtained from electromagnetic analysis, loss analysis, heat flow coupling computational fluid dynamics analysis, structural analysis, and rotor dynamics analysis. Second, the CFRP sleeve was designed by theoretical analysis. From the results, the thickness values of the carbon fibers in the circumferential and helical directions were chosen to be 4 and 1 mm, respectively, while the helical angle of carbon fibers was chosen to be 70°. Then, a plate-shaped CFRP product and a cylindrical CFRP product were fabricated to verify the strength and stiffness of the CFRP sleeve. The performance test results show that the hoop strength and elastic modulus and the axial strength and elastic modulus of the plate-shaped CFRP products at 20 °C are 1963 MPa @ 156 GPa and 550 MPa @ 36 GPa, respectively. The hoop strain and axial strain of the cylindrical CFRP product under 35 MPa are about 3000 and 1900 μe, which meet the design requirements of the HSPMSM.

Force parameters of metal deformation during sheet drawing

The aim of the work. The effect of the curvature of the rounding of torus surfaces during the formation of a cylindrical product (glass) is investigated, taking into account the plastic thinning of the deformable material at the end edges of the matrix and pressing punch. Methods. The existing scheme for determining the power parameters of sheet drawing is analyzed, based on the assumption of the implementation of some abstract stress state in the material; mainly conditional tensile strength. At the same time, the possibility of forming the product without destruction determines the obvious overestimation of the stress level. A mathematical model of the volumetric stress state of the metal is being developed, which makes it possible to assess the deformation and stress state during the formation of a cold-drawn product, i. e. the folding of the sheet blank along the end radius of the rounding of the pressing punch and the steady-state process of drawing the blank into the deformation zone with successive bending/straightening of the material along the edge of the matrix are considered. The level of radial stresses during folding and stretching of sheet material is estimated, taking into account its strain hardening and thinning, which determine the forming force. The obtained results will make it possible to simulate the stress-strain state of the metal during the development of sheet drawing technology: to establish the amount of thinning, to estimate the level of radial stresses in the formation of rounding of torus surfaces along the end edges of the matrix and the pressing punch, as well as to determine the power parameters of the formation, which will prevent the destruction of the pulled part, guaranteeing obtaining high-quality products and more accurately choosing the deforming equipment.

A Method for Increasing the Fatigue Life of Pump Rods

A method for increasing the fatigue life of pump rods and similar elongated cylindrical products is considered. The method consists in creating normal compressing residual stresses in the near-surface region of the product; the stresses are created by sequential elastoplastic deformation: first, by extension, then, when fixed under axial strain, by torsion. It is shown how the residual stresses are generated in the bulk product during its hardening by combined extension and torsion.

EXPLOSIVE WELDING OF HEAT RESISTANT ALLOYS BASED ON REFRACTORY METALS WITH HIGH STRENGTH STEEL

In this work, the parameters of explosive welding of plates and pipes from heat resistant alloys with high-strength steel were established. It was found that to ensure strong adhesion, it is necessary to increase the kinetic energy of a flayer plate made of a heat-resistant alloy several times in comparison with the explosion welding of steel sheets. Metallographic studies have shown that at similar modes of explosion welding in cylindrical products, the number of cast inclusions is significantly increased compared to sheets up to the appearance of a continuous layer at the weld interface. Mechanical tests have confirmed the quality of the joint. This material is promising for work in structures experiencing thermal and erosive effects.

Investigation of Optimized Parameters for Magnetorheological Finishing the Internal Surface of the Cast-Iron Cylindrical Molds

The cylindrical mold is an essential part used in industries for the manufacturing of various cylindrical products such as beverages canes, domestics appliances, glass beakers, and polyvinyl chloride pipes. These products require features in its surfaces such as defect-free surfaces with high-quality, stable dimensions, the high extent of cylindricity, and functional transparency in glass material products. To acquire such features in the cylindrical products, the rotary magnetorheological honing (R-MRH) process is developed. In this work, the response surface methodology technique is employed for optimizing the process parameters for internal surface finishing of the cast-iron (CI) cylindrical workpieces. With the optimized process parameters, the experiments are performed to find out the effectiveness of the present finishing process for CI cylindrical molds. On the final MR-finished surface after 40 min of finishing, the roughness parameters (Ra, Rz, and Rq) get reduced to 0.05 µm, 0.4 µm, and 0.07 µm from the respective initial values of 0.420 µm, 2.4 µm, and 0.52 µm. The waviness parameters (Wa, Wz, and Wq) achieved on the final finished surface are 0.04 µm, 0.20 µm, and 0.06 µm from the initial values of 0.17 µm, 0.90 µm, and 0.22 µm, respectively. Also, the circularity (C) on the MR-finished cylindrical surface is improved to 0.0437 from the initial circularity value of 0.1207. The significant changes in Ra, Wa, and C values as well as visuals of scanning electron microscopy images reveal a better sense of functionality improvement of the cast-iron cylindrical molds.

Analysis of the material flow in combined extrusion of steel bar stocks with a conical tool

In the manufacture of cylindrical products made of steel, representing a set of two thin-walled hollow cylindrical surfaces of different diameters with a bridge in the center, extrusion as a basic operation for their manufacture looks uncompromised. In order to reduce specific pressures during backward extrusion, various methods are used, from changing the working geometry of the tool and material temperatures to the variation of the friction coefficient using various lubricants. All this affects the nature of the flow and the degree of formation of the product’s walls. Therefore, the urgent task is to analyze the influence of technological parameters on the nature of the material flow during the combined extrusion of steel bar stocks with a conical tool. On the basis of finite element modeling, the article reveals the influence of various technological factors on the velocity of the material and its degree of flow into the working cavities of the die. The results can be useful in the selection of technological modes of manufacturing products similar in size by means of combined extrusion.

New Approach to Make Cylindrical Packaging Products in Rotation Around Their Fixed Axis During Irradiation in the Monte Carlo Simulation

This article, presents an approach to make the cylindrical packaging products in rotation around their fixed axis, in the Monte Carlo simulation during irradiation. This approach will solve the rotating plats around its fixed axis problem in the simulation so can be used to improve the dose uniformity and predict the irradiated products packaging form, taking into account its density and its position in the irradiation cell, to save time and the high costs of the experiments. This study has released at Moroccan gamma irradiation station. We have used the MCNPX code to simulate this approach. The validation has been done by an experiment measurement using sugar as a product and alanine dosimeters for dosimetric calculation.