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Modeling and Experimental Analysis of Metal Forming and Cutting

A special issue of Materials (ISSN 1996-1944). This special issue belongs to the section "Materials Simulation and Design".

Deadline for manuscript submissions: closed (20 December 2022) | Viewed by 28205

Special Issue Editor


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Guest Editor
Faculty of Mechanical Engineering, Department of Mechanics and Construction, Technical University of Koszalin, 75-453 Koszalin, Poland
Interests: metal forming processes; non-linear mechanics; non-linear contact mechanics; FEM and SPH methods; numerical modeling, simulation and numerical analysis; thermodynamics of non-elastic materials; theory of plasticity; digital materials modelling
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Special Issue Information

Dear Colleagues,

Metal forming and cutting processes have been a very important branch of industries for many years. Recently, in addition to the already known methods, new technologies have been introduced into production. The products after these processes are used in almost all areas of our lives, from cars, ships, and aircraft to washing machines and computers and knee and hip joint prostheses. Increasingly, products made with traditional treatments, such as turning and grinding, are being replaced by plastically deformed products.

The development of metal forming and cutting technology in recent years has necessitated the improvement of analysis methods applied for these processes. For a long time, difficulties associated with the strongly nonlinear nature of such a process did not allow reaching precise and universal methods of its analysis. One of the basic practical problems is to determine the optimal parameters of the forming and cutting processes to obtain a high-quality product with minimum manufacturing costs. In recent years, an extremely rapid development has been taking place in the field of continuous media theory, plasticity theory, and numerical methods of mechanics, with the progress of computational systems and specialized software. New methods of analysis of physical phenomena accompanying the deformation process are being introduced, which allow states of displacement, strain, and stress to be determined with greater accuracy, both during and after the processing. New metals and alloys are being introduced into production, and newer methods of determining material constants and new algorithms for approximate solution of motion equations and non-linear contact. This creates conditions in which analyzing complex problems of plastic forming has become possible.

Therefore, metal forming and cutting processes are of interest to scientists and researchers from universities, research institutes, and industry from all over the world. This is an excellent motivation to organize a Special Issue on “Modeling and Experimental Analysis of Metal Forming and Cutting” as a forum to present the state-of-the-art and disseminate the latest developments, innovations, and progress in this field of science and technology.

Original papers are solicited on various technologies and processes of metal forming, such as: rolling, forging, sheet forming, incremental forming, extrusion, drawing, joining and hydroforming, and micro- and nano-forming and mechanical cutting— shear-slitting, punching and guillotining, and non-mechanical cutting, such as laser cutting. Articles and reviews dealing with the results of a very wide spectrum of research with material modeling, constitutive models, contact problems, deformation mechanics, process and system modeling, numerical solutions and simulations, modeling and measurements of physical phenomena during manufacturing processes to predict and evaluation of product quality, material behavior during deformation, and properties of the final products after deformation are very welcome.

Prof. Dr. Leon Kukiełka
Guest Editor

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Keywords

  • metal forming;
  • cutting;
  • constitutive models;
  • contact mechanics;
  • FEM;
  • SPH;
  • plasticity;
  • deformation mechanics;
  • modeling and testing of material properties;
  • process and system modeling

Published Papers (14 papers)

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Research

40 pages, 30955 KiB  
Article
Application of the FEM Method to Modeling and Analysis of the Cold Thread Rolling Process—Part 1: Conditions for Ensuring a Plane State of Deformations
by Krzysztof Kukiełka
Materials 2023, 16(13), 4647; https://doi.org/10.3390/ma16134647 - 27 Jun 2023
Viewed by 1358
Abstract
The article concerns the application of the FEM method for the prediction of stress and deformation states in a workpiece during the thread rolling process (TR). The analysis covered a new kinematic variant of the TR process in which the basket of the [...] Read more.
The article concerns the application of the FEM method for the prediction of stress and deformation states in a workpiece during the thread rolling process (TR). The analysis covered a new kinematic variant of the TR process in which the basket of the head rotates and is torque-driven, while the workpiece is stationary and the head with the rollers moves axially relative to the workpiece. The TR process was considered as a geometrical and physical non-linear initial and boundary problem with non-linear, moving, and variable in time and space boundary conditions. The boundary conditions in the contact areas of the tool with the workpiece were unknown. An updated Lagrange (UL) description was used to describe the physical phenomena at a typical incremental step. The states of strain and strain rate were described by non-linear relationships without linearization. New discrete systems of motion and deformation equations of the object in the TR were introduced, which take into account the change in the stiffness of the system during the TR process. This equation was solved by the central differences method (explicit). The material parameters were estimated during tensile tests to determine the characteristics of the C45 steel, and a new semi-empirical method was used to determine the relationship yield stress, effective true strain, and effective true strain rate in the thread rolling process. A modified Cowper–Symonds material model was also used to model the displacement process of the wedge on an elastic/visco-plastic body reflecting the TR process. A non-linear dependency of material hardening module depending on strain and strain rate was introduced. To confirm the plane state of deformation and spatial state of stress, an experimental investigation was carried out. The computer models were validated, and a good convergence of the results was obtained. Applications in the ANSYS/LS-Dyna program were developed to simulate the TR process. The developed applications enable a comprehensive time analysis of the states of displacement, strain, and stress occurring in an object consisting of a workpiece (shaft) and a tool (roller) for the case of a plane strain state and a spatial stress state. Exemplary results of numerical analyzes are presented to explain the influence of the friction coefficient on the condition of the thread quality, and the state of deformations and stresses were shown. Full article
(This article belongs to the Special Issue Modeling and Experimental Analysis of Metal Forming and Cutting)
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14 pages, 6691 KiB  
Article
Preliminary Studies into Cutting of a Novel Two Component 3D-Printed Stainless Steel–Polymer Composite Material by Abrasive Water Jet
by Tomasz Szatkiewicz, Andrzej Perec, Aleksandra Radomska-Zalas, Kamil Banaszek and Blazej Balasz
Materials 2023, 16(3), 1170; https://doi.org/10.3390/ma16031170 - 30 Jan 2023
Cited by 8 | Viewed by 1575
Abstract
Composites are materials with a heterogeneous structure, composed of two or more components with different properties. The properties of composites are never the sum or average of the properties of their components. There is a lot of research and many models on the [...] Read more.
Composites are materials with a heterogeneous structure, composed of two or more components with different properties. The properties of composites are never the sum or average of the properties of their components. There is a lot of research and many models on the different property assessments of composite materials. Composites are used as construction materials in key areas of technology, including in civil and mechanical engineering, aviation and space technology, and others. This work presents a modern composite material created with 3D-printing technology using the SLM method, and the possibility of its processing with one of the advanced manufacturing technologies, i.e., the Abrasive Water Jet (AWJ). Tests planned using DoE methods were carried out by changing control parameters such as the pressure, abrasive flow, and traverse speed. As a dependent parameter, the surface roughness parameter Sq (squared mean height) was selected and measured in different places of the cut composite. Based on the S/N ratio, the most favorable control parameters of the cutting process were also determined to achieve the lowest roughness of the cut surface. A clear effect of the controlled cutting process on the surface roughness was observed, as well as roughness variation for the metal and polymer component. In addition, the contact surface of the polymer with the metal in the cut zone was analyzed. Analysis of the contact surfaces on the microscope showed that the gap between the polymer–metal contact surfaces does not exceed 2.5 μm. Full article
(This article belongs to the Special Issue Modeling and Experimental Analysis of Metal Forming and Cutting)
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21 pages, 16226 KiB  
Article
Forecasting the Fatigue Strength of DC01 Cold-Formed Angles Using the Anisotropic Barlat Model
by Mateusz Miksza, Łukasz Bohdal, Paweł Kałduński, Radosław Patyk and Leon Kukiełka
Materials 2022, 15(23), 8436; https://doi.org/10.3390/ma15238436 - 26 Nov 2022
Cited by 3 | Viewed by 1334
Abstract
The objective of this work is to present the numerical simulation of the air-bending process of DC01 steel. There are plenty of works concerned with assessing the springback phenomenon in the bending process also using anisotropic material models (Hill’s model is widely used). [...] Read more.
The objective of this work is to present the numerical simulation of the air-bending process of DC01 steel. There are plenty of works concerned with assessing the springback phenomenon in the bending process also using anisotropic material models (Hill’s model is widely used). However, very few recent publications are concerned about the fatigue life assessment of bent products. As ensuring the proper fatigue resistance of products is vital for increasing safety and widening the service intervals there is certainly a need to perform investigations in this field. In this work, the air bending simulation of anisotropic DC01 steel with the usage of Barlat’s plastic anisotropy model was presented. Together with springback analysis and the equivalent plastic strain cumulation during incremental bending. Strain cumulation is believed to be an important factor in predicting fatigue life. It was shown that the strain development rate depends on the bending process parameters, especially from the bending line orientation to the sheet rolling direction. Full article
(This article belongs to the Special Issue Modeling and Experimental Analysis of Metal Forming and Cutting)
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16 pages, 5531 KiB  
Article
Efficiency of Tool Steel Cutting by Water Jet with Recycled Abrasive Materials
by Andrzej Perec, Aleksandra Radomska-Zalas, Anna Fajdek-Bieda and Elzbieta Kawecka
Materials 2022, 15(11), 3978; https://doi.org/10.3390/ma15113978 - 2 Jun 2022
Cited by 13 | Viewed by 1700
Abstract
High-pressure water jet machining is characterized by wide possibilities of cutting diverse materials together with multi-layer materials with dissimilar properties, accurate cutting complex profiles, as well as conducting them in uncommon conditions, especially in cases of thick materials. An additional advantage of water [...] Read more.
High-pressure water jet machining is characterized by wide possibilities of cutting diverse materials together with multi-layer materials with dissimilar properties, accurate cutting complex profiles, as well as conducting them in uncommon conditions, especially in cases of thick materials. An additional advantage of water jet technology is its environmental friendliness. This paper presents tests of the cutting performance of tool steel with the use of an abrasive water jet (AWJ). The state-of-the-art has shown insufficient scientific evidence in AWJ tool steels cutting using recycled abrasive materials. Therefore, the main motivation for this paper was to carry out research from an environment aspect. The reuse of abrasives and the use of recycled materials have immense potential to reduce processing costs while remaining environmentally friendly. The RSM method was used for modeling and optimization. A response surface design (RSM) is a package of an advanced design-of-experiment (DOE) approaches that support better understanding and optimize response, exploring the relationships between several explanatory variables and one or more response variables. Based on this research, feed rate is the key factor influencing the depth of cut, while the water nozzle diameter has a secondary effect, and the concentration of abrasive has the least influence on the depth of cut. High level of variance (the percentage of variability in the reaction that is interpreted by the formula) confirms that the models fit well to the investigational data. Full article
(This article belongs to the Special Issue Modeling and Experimental Analysis of Metal Forming and Cutting)
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21 pages, 6480 KiB  
Article
Experimental and Numerical Studies of Tool Wear Processes in the Nibbling Process
by Łukasz Bohdal, Leon Kukiełka, Radosław Patyk, Katarzyna Kośka, Jarosław Chodór and Konrad Czyżewski
Materials 2022, 15(1), 107; https://doi.org/10.3390/ma15010107 - 24 Dec 2021
Cited by 6 | Viewed by 2557
Abstract
The work concerns an analysis of the wear mechanisms of punches in the nibbling process. The nibbling process is the multiple punching of holes or external contours using circular punches, the diameter of which is much smaller than the size of the punched [...] Read more.
The work concerns an analysis of the wear mechanisms of punches in the nibbling process. The nibbling process is the multiple punching of holes or external contours using circular punches, the diameter of which is much smaller than the size of the punched shapes. Analytical, numerical and experimental studies were carried out. In the analytical solution, formulas for determining the pressures in the contact zone were developed, thus enabling a simple estimation of the designed nibbling tools. In numerical studies, the influence of the punch rounding radius on the fatigue wear was investigated. It has been shown that the change in the punch cutting edge radius from r = 0 mm to r = 0.5 mm enables a seven-fold increase in the fatigue wear resistance. It was found that the change in the punch cutting edge rounding radius has an impact on the quality of the product (the greater the radius r, the worse the technological quality of the product). In experimental studies, the abrasive wear process was primarily investigated. For this purpose, the nibbling process was tested on S235JR + AR steel sheets with tools made of NC11LV/1.2379 steel without any coating and with an AlCrTiN layer. It was found that the special AlCrTiN layer used allowed for an increase in the resistance to abrasive wear, and thus increased the service life by approx. three times. The last element of the work is an assessment of the technological quality of the product after nibbling depending on the degree and type of stamp wear (quantitative and qualitative assessment). Full article
(This article belongs to the Special Issue Modeling and Experimental Analysis of Metal Forming and Cutting)
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21 pages, 7326 KiB  
Article
Non-Symmetrical Direct Extrusion—Analytical Modelling, Numerical Simulation and Experiment
by Marek Kowalik, Piotr Paszta, Tomasz Trzepieciński and Leon Kukiełka
Materials 2021, 14(24), 7856; https://doi.org/10.3390/ma14247856 - 18 Dec 2021
Viewed by 2244
Abstract
The article presents the original technology of the extrusion of hollow curved pipes. The curvature radius of pipe axis was obtained directly during extrusion by eccentric alignment of the annular calibration gap of the extrusion die. Theoretical relationships describing the radius of curvature [...] Read more.
The article presents the original technology of the extrusion of hollow curved pipes. The curvature radius of pipe axis was obtained directly during extrusion by eccentric alignment of the annular calibration gap of the extrusion die. Theoretical relationships describing the radius of curvature of the extruded part as a function of the eccentricity e of position of the annular calibration gap in the die were developed. A die with replaceable inserts with eccentricity e equal to 1, 2, 3, 5, 7 mm was designed and fabricated. Experimental tests were carried out to extrude lead pipes with an outer diameter of 20 mm and an inner diameter of 18 mm. Measurements of the radii of the curvature of the extruded pipes were consistent with the values calculated from the developed theoretical relationships. Numerical modelling of the proposed method of extrusion in a finite element-based QForm 3D program was carried out. The finite element method (FEM) numerical calculations were carried out for lead. Numerical simulations and experimental studies have shown that, by changing the value of the eccentric gap, the radius of curvature of the extruded pipe can be controlled. Full article
(This article belongs to the Special Issue Modeling and Experimental Analysis of Metal Forming and Cutting)
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22 pages, 93265 KiB  
Article
Influence of Semi-Random and Regular Shot Peening on Selected Surface Layer Properties of Aluminum Alloy
by Jakub Matuszak, Kazimierz Zaleski, Agnieszka Skoczylas, Krzysztof Ciecieląg and Krzysztof Kęcik
Materials 2021, 14(24), 7620; https://doi.org/10.3390/ma14247620 - 10 Dec 2021
Cited by 16 | Viewed by 2415
Abstract
This paper attempts to compare regular shot peening (RSP) and semi-random shot peening (SRSP). A characteristic of the first method is that the peening elements hit the treated surface in sequence, with a regular distance maintained between the dimples. The other method (SRSP) [...] Read more.
This paper attempts to compare regular shot peening (RSP) and semi-random shot peening (SRSP). A characteristic of the first method is that the peening elements hit the treated surface in sequence, with a regular distance maintained between the dimples. The other method (SRSP) is a controlled modification of the shot-peening process, which is random by nature. The shot-peening method used in this study differs from conventional shot peening (shot blasting and vibratory shot peening) in that it allows controlled and repeatable determination of the configuration and distribution of impacts exerted by the peening element on the workpiece surface, which makes the process more repeatable and easier to model. Specimens of EN-AW 7075 aluminum alloy were used for testing. The following variables were used in the experiments: ball diameter, impact energy, and distance between the dimples. Microhardness distribution in the surface layer, 2D surface roughness, and surface topography were analyzed. FEM simulations of the residual stress distribution in the surface layer were performed. It has been found that regular shot peening results in reduced surface roughness, while semi-random shot peening leads to higher surface layer hardening. Full article
(This article belongs to the Special Issue Modeling and Experimental Analysis of Metal Forming and Cutting)
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23 pages, 11451 KiB  
Article
Experimental and Numerical Analysis of the Depth of the Strengthened Layer on Shafts Resulting from Roller Burnishing with Roller Braking Moment
by Marek Kowalik, Tomasz Trzepieciński, Leon Kukiełka, Piotr Paszta, Paweł Maciąg and Stanisław Legutko
Materials 2021, 14(19), 5844; https://doi.org/10.3390/ma14195844 - 6 Oct 2021
Cited by 12 | Viewed by 1591
Abstract
The article presents the results of investigations into the depth of the plastically deformed surface layer in the roller burnishing process. The investigation was carried out in order to obtain information on the dependence relationship between the depth of plastic deformation, the pressure [...] Read more.
The article presents the results of investigations into the depth of the plastically deformed surface layer in the roller burnishing process. The investigation was carried out in order to obtain information on the dependence relationship between the depth of plastic deformation, the pressure on the roller and the braking torque. The research was carried out according to the original method developed by the authors, in which the depth of plastic deformation is increased by applying a braking torque to the burnishing roller. In this method, it is possible to significantly increase (up to 20%) the depth of plastic deformation of the surface layer. The tests were carried out on a specially designed device on which the braking torque can be set and the force of the rolling resistance of the roller during burnishing can be measured. The tests were carried out on specimens made of C45 heat-treatable carbon steel. The dependence of the depth of the plastically deformed surface layer was determined for a given pressure force and variable braking moments. The depth of the plastically deformed layer was measured on the deformed end face of the ring-shaped samples. The microhardness in the sample cross-section and the evolution of the microstructure were both analysed. Full article
(This article belongs to the Special Issue Modeling and Experimental Analysis of Metal Forming and Cutting)
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14 pages, 21220 KiB  
Article
Research into the Disintegration of Abrasive Materials in the Abrasive Water Jet Machining Process
by Andrzej Perec
Materials 2021, 14(14), 3940; https://doi.org/10.3390/ma14143940 - 14 Jul 2021
Cited by 22 | Viewed by 2528
Abstract
The size and distribution of abrasive particles have a significant influence on the effectiveness of the cutting process by the high-speed abrasive water jet (AWJ). This paper deals with the disintegration intensity of abrasive materials in AWJ cutting during the creation of the [...] Read more.
The size and distribution of abrasive particles have a significant influence on the effectiveness of the cutting process by the high-speed abrasive water jet (AWJ). This paper deals with the disintegration intensity of abrasive materials in AWJ cutting during the creation of the abrasive jet. An evaluation of the abrasive materials was performed after forming in the cutting head was carried out and grain distribution was evaluated using the geometric and logarithmic Folk and Ward method. The influence of the abrasive concentration of abrasive materials such as alluvial garnet, recycled garnet, corundum, and olivine on grain distribution was studied. A recovery analysis was also carried out and the recycling coefficient was determined for each abrasive material tested. Full article
(This article belongs to the Special Issue Modeling and Experimental Analysis of Metal Forming and Cutting)
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20 pages, 24781 KiB  
Article
Central Composite Design Optimisation in Single Point Incremental Forming of Truncated Cones from Commercially Pure Titanium Grade 2 Sheet Metals
by Marcin Szpunar, Robert Ostrowski, Tomasz Trzepieciński and Ľuboš Kaščák
Materials 2021, 14(13), 3634; https://doi.org/10.3390/ma14133634 - 29 Jun 2021
Cited by 13 | Viewed by 2095
Abstract
Single point incremental forming (SPIF) is an emerging process that is well-known to be suited for fabrication in small series production. The aim of this paper was to determine the optimal input parameters of the process in order to minimise the maximum of [...] Read more.
Single point incremental forming (SPIF) is an emerging process that is well-known to be suited for fabrication in small series production. The aim of this paper was to determine the optimal input parameters of the process in order to minimise the maximum of both the axial and the in-plane components of the forming force achieved during SPIF and the surface roughness of the internal surface of truncated-cone drawpieces. Grade 2 pure titanium sheets with a thickness of 0.4 mm were used as the test material. The central composite design and response surface method was used to determine the number of experiments required to study the responses through building a second-order quadratic model. Two directions of rotation of the forming tool were also considered. The input parameters were spindle speed, tool feed rate, and step size. The mathematical relations were defined using the response surfaces to predict the surface roughness of the drawpieces and the components of the forming force. It was found that feed rate has an insignificant role in both axial and in-plane forming forces, but step size is a major factor affecting axial and radial forming forces. However, step size directly affects the surface roughness on the inner surfaces of the drawpieces. Overall, the spindle speed −579 rpm (clockwise direction), tool feed 2000 mm/min, and step size 0.5 mm assure a minimisation of both force components and the surface roughness of drawpieces. Full article
(This article belongs to the Special Issue Modeling and Experimental Analysis of Metal Forming and Cutting)
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14 pages, 5953 KiB  
Article
Microstructure and Hot Deformation Behavior of the Mg–8 wt.% Sn–1.5 wt.% Al Alloy
by Zhaoqian Sun, Yongjun Li, Kui Zhang, Xinggang Li, Minglong Ma, Guoliang Shi, Jiawei Yuan and Hongju Zhang
Materials 2021, 14(8), 2050; https://doi.org/10.3390/ma14082050 - 19 Apr 2021
Cited by 5 | Viewed by 1751
Abstract
Mg–Sn–Al alloy is a new type of heat-resistant magnesium alloy with great potential and the hot deformation process of this alloy is of great significance for its application. The microstructure, hot deformation behavior, textural evolution, and processing map of a Mg–8 wt.% Sn–1.5 [...] Read more.
Mg–Sn–Al alloy is a new type of heat-resistant magnesium alloy with great potential and the hot deformation process of this alloy is of great significance for its application. The microstructure, hot deformation behavior, textural evolution, and processing map of a Mg–8 wt.% Sn–1.5 wt.% Al alloy were studied. A Gleeble 1500 D thermo-mechanical simulator was used. The temperature of deformation was 653 to 773 K, the strain rate was 0.001–1 s−1, and the maximum deformation degree was 60%. The obtained results show that the rheological stress of the alloy decreases with an increase in deformation temperature and increases with an increase in the strain rate. The alloy is completely dynamically recrystallized at 653 K, and the entire structure is formed of homogeneous crystals/grains, with small secondary phase particles distributed at the crystal boundary. The mean apparent activation energy of hot compression deformation is 153.5 kJ/mol. The Mg–8 wt.% Sn–1.5 wt.% Al alloy exhibits excellent plastic deformation properties, an expansive thermal processing interval, and a narrow instability zone under the test temperature and deformation rate. The optimal process parameters of the alloy comprise deformation temperatures between 603 and 633 K and strain rates of 0.03 to 0.005 s−1. Full article
(This article belongs to the Special Issue Modeling and Experimental Analysis of Metal Forming and Cutting)
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19 pages, 6108 KiB  
Article
Finite Plane Strain Bending under Tension of Isotropic and Kinematic Hardening Sheets
by Stanislav Strashnov, Sergei Alexandrov and Lihui Lang
Materials 2021, 14(5), 1166; https://doi.org/10.3390/ma14051166 - 2 Mar 2021
Cited by 1 | Viewed by 1491
Abstract
The present paper provides a semianalytic solution for finite plane strain bending under tension of an incompressible elastic/plastic sheet using a material model that combines isotropic and kinematic hardening. A numerical treatment is only necessary to solve transcendental equations and evaluate ordinary integrals. [...] Read more.
The present paper provides a semianalytic solution for finite plane strain bending under tension of an incompressible elastic/plastic sheet using a material model that combines isotropic and kinematic hardening. A numerical treatment is only necessary to solve transcendental equations and evaluate ordinary integrals. An arbitrary function of the equivalent plastic strain controls isotropic hardening, and Prager’s law describes kinematic hardening. In general, the sheet consists of one elastic and two plastic regions. The solution is valid if the size of each plastic region increases. Parameters involved in the constitutive equations determine which of the plastic regions reaches its maximum size. The thickness of the elastic region is quite narrow when the present solution breaks down. Elastic unloading is also considered. A numerical example illustrates the general solution assuming that the tensile force is given, including pure bending as a particular case. This numerical solution demonstrates a significant effect of the parameter involved in Prager’s law on the bending moment and the distribution of stresses at loading, but a small effect on the distribution of residual stresses after unloading. This parameter also affects the range of validity of the solution that predicts purely elastic unloading. Full article
(This article belongs to the Special Issue Modeling and Experimental Analysis of Metal Forming and Cutting)
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14 pages, 2536 KiB  
Article
Fatigue Reliability Analysis Method of Reactor Structure Considering Cumulative Effect of Irradiation
by Bo Sun, Junlin Pan, Zili Wang, Yi Ren, Dariusz Mazurkiewicz, Małgorzata Jasiulewicz-Kaczmarek and Katarzyna Antosz
Materials 2021, 14(4), 801; https://doi.org/10.3390/ma14040801 - 8 Feb 2021
Cited by 3 | Viewed by 1895
Abstract
The influence of irradiation should be considered in fatigue reliability analyses of reactor structures under irradiation conditions. In this study, the effects of irradiation hardening and irradiation embrittlement on fatigue performance parameters were quantified and a fatigue life prediction model was developed. Based [...] Read more.
The influence of irradiation should be considered in fatigue reliability analyses of reactor structures under irradiation conditions. In this study, the effects of irradiation hardening and irradiation embrittlement on fatigue performance parameters were quantified and a fatigue life prediction model was developed. Based on this model, which takes into account the cumulative effect of a neutron dose, the total fatigue damage was calculated according to Miner’s linear cumulative damage law, and the reliability analysis was carried out using the Monte Carlo simulation method. The case results show that the fatigue life acquired by taking into account the cumulative effect of irradiation was reduced by 24.3% compared with that acquired without considering the irradiation effect. Irradiation led to the increase of the fatigue life at low strains and its decrease at high strains, which is in accordance with the findings of an irradiation fatigue test. The rate of increase in the fatigue life decreased gradually with the increase of the neutron dose. The irradiation performance parameters had a small influence on fatigue reliability, while the fatigue strength coefficient and the elastic modulus had a great influence on the fatigue reliability. Compared with the current method, which uses a high safety factor to determine design parameters, a fatigue reliability analysis method taking into account the cumulative effect of irradiation could be more accurate in the reliability analysis and life prediction of reactor structures. Full article
(This article belongs to the Special Issue Modeling and Experimental Analysis of Metal Forming and Cutting)
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18 pages, 9474 KiB  
Article
Dimensional Analysis of Workpieces Machined Using Prototype Machine Tool Integrating 3D Scanning, Milling and Shaped Grinding
by Piotr Jaskólski, Krzysztof Nadolny, Krzysztof Kukiełka, Wojciech Kapłonek, Danil Yurievich Pimenov and Shubham Sharma
Materials 2020, 13(24), 5663; https://doi.org/10.3390/ma13245663 - 11 Dec 2020
Cited by 4 | Viewed by 2152
Abstract
In the literature, there are a small number of publications regarding the construction and application of machine tools that integrate several machining operations. Additionally, solutions that allow for such integration for complex operations, such as the machining of shape surfaces with complex contours, [...] Read more.
In the literature, there are a small number of publications regarding the construction and application of machine tools that integrate several machining operations. Additionally, solutions that allow for such integration for complex operations, such as the machining of shape surfaces with complex contours, are relatively rare. The authors of this article carried out dimensional analysis of workpieces machined using a prototype Computerized Numerical Control (CNC) machine tool that integrates the possibilities of 3D scanning, milling operations in three axes, and grinding operations using abrasive discs. The general description of this machine tool with developed methodology and the most interesting results obtained during the experimental studies are given. For a comparative analysis of the influence of the machining method on the geometric accuracy of the test pieces, an Analysis of Variance (ANOVA) was carried out. The obtained results show that for four considered features (deviations of flatness, vertical parallelism, opening dimensions, and opening cylindricality), no statistically significant differences were detected. For the evaluation criteria, the probability level p exceeded the assumed confidence level α = 0.05 and ranged from p = 0.737167 to p = 0.076764. However, such differences were found for two others—a dimensional deviation between flat surfaces (p = 0.010467) and horizontal parallelism deviation (p = 0.0)—as well as for the quality of the machined surface defined by four surface texture parameters: Ra (p = 0.831797), Rt (p = 0.759636), Rq (p = 0.867222), and Rz (p = 0.651896). The information obtained by the ANOVA will be useful for the elimination the weaknesses of the prototype machine tool, further analysis of technological strategies, and to find possible benefits of integrating machining operations. Full article
(This article belongs to the Special Issue Modeling and Experimental Analysis of Metal Forming and Cutting)
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