Meelad Ranaiefar, P. Honarmandi, Lei Xue, Chen Zhang, A. Elwany, I. Karaman, E. Schwalbach, R. Arróyave
The desire for increased performance and functionality has introduced additional complexities to the design and fabrication of additively manufactured (AM) parts. However, addressing these needs would require improved control over local properties during the fabrication process. In this regard, differential evaporation is an inherent characteristic in metal AM processes, directly influencing local chemistry, material properties, functionality, and performance. In the present work, a differential evaporation model (DEM) is presented for laser powder bed fusion (LPBF) AM to predict and control the effect of evaporation on chemistry and properties on local and part-wide scales. The DEM model is coupled with an analytical thermal model that is calibrated against 51.2 Ni [at.%] nickel titanium SMA single-track experiments and a multi-layer model that accounts for the AM part’s multi-layer design and the inherent melt pool overlap and chemistry propagation. The combined hierarchical model, consisting of the thermal, evaporation, and multi-layer components, is used to predict location-specific chemistry for LBPF AM fabrication of 50.8 Ni [at.%] nickel titanium shape memory alloys(NiTi SMAs). Model predictions are validated with values obtained from multi-layer experiments on a commercial LPBF system, resulting in a root mean square error (RMSE) of 0.25 Ni [at.%] for predicted Ni content. Additionally, martensitic transformation temperature, Ms, is calculated and compared with empirical data, resulting in an RMSE of 18.6 K. A practical account of the cumulative and propagative thermal-induced evaporation effect on location-specific chemistry is made through this linkage of models. Fundamentally, this model chain has also provided a solution to the forward modeling problem, enabling steps to be taken towards resolving the inverse design problem of deter-mining processing parameters based on desired location-specific properties.
对提高性能和功能的渴望为增材制造(AM)零件的设计和制造带来了额外的复杂性。然而，要满足这些需求，就需要在制造过程中改进对当地特性的控制。在这方面，微分蒸发是金属增材制造工艺的固有特性，直接影响到局部化学、材料特性、功能和性能。本文提出了激光粉末床熔合AM的微分蒸发模型(DEM)，以预测和控制蒸发对局部和局部范围内化学和性能的影响。DEM模型与51.2 Ni [at校准的解析热模型相结合。%]镍钛SMA单轨实验和多层模型，该模型解释了增材制造部件的多层设计以及固有的熔池重叠和化学传播。该组合分层模型由热、蒸发和多层组件组成，用于预测LBPF AM制造50.8 Ni [at的特定位置化学。镍钛形状记忆合金(NiTi sma)。通过商用LPBF系统的多层实验验证了模型预测值，得出均方根误差(RMSE)为0.25 Ni [at]。%]表示预测的Ni含量。此外，计算了马氏体相变温度Ms，并与经验数据进行了比较，得出RMSE为18.6 K。通过这种模式的联系，对累积和传播的热诱导蒸发对特定地点化学的影响进行了实际的说明。从根本上说，该模型链还为正演建模问题提供了解决方案，从而可以采取步骤解决基于所需位置特定属性确定加工参数的反设计问题。
{"title":"A Differential Evaporation Model to Predict Chemistry Change of Additively Manufactured Metals","authors":"Meelad Ranaiefar, P. Honarmandi, Lei Xue, Chen Zhang, A. Elwany, I. Karaman, E. Schwalbach, R. Arróyave","doi":"10.2139/ssrn.3813432","DOIUrl":"https://doi.org/10.2139/ssrn.3813432","url":null,"abstract":"The desire for increased performance and functionality has introduced additional complexities to the design and fabrication of additively manufactured (AM) parts. However, addressing these needs would require improved control over local properties during the fabrication process. In this regard, differential evaporation is an inherent characteristic in metal AM processes, directly influencing local chemistry, material properties, functionality, and performance. In the present work, a differential evaporation model (DEM) is presented for laser powder bed fusion (LPBF) AM to predict and control the effect of evaporation on chemistry and properties on local and part-wide scales. The DEM model is coupled with an analytical thermal model that is calibrated against 51.2 Ni [at.%] nickel titanium SMA single-track experiments and a multi-layer model that accounts for the AM part’s multi-layer design and the inherent melt pool overlap and chemistry propagation. The combined hierarchical model, consisting of the thermal, evaporation, and multi-layer components, is used to predict location-specific chemistry for LBPF AM fabrication of 50.8 Ni [at.%] nickel titanium shape memory alloys(NiTi SMAs). Model predictions are validated with values obtained from multi-layer experiments on a commercial LPBF system, resulting in a root mean square error (RMSE) of 0.25 Ni [at.%] for predicted Ni content. Additionally, martensitic transformation temperature, Ms, is calculated and compared with empirical data, resulting in an RMSE of 18.6 K. A practical account of the cumulative and propagative thermal-induced evaporation effect on location-specific chemistry is made through this linkage of models. Fundamentally, this model chain has also provided a solution to the forward modeling problem, enabling steps to be taken towards resolving the inverse design problem of deter-mining processing parameters based on desired location-specific properties.","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"151 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77092103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Low temperature heterogeneous integration with diamond is the key technology in pushing upwards the high-power limit of a vertically-external-cavity surface-emitting laser (VECSEL). This work successfully accomplished a functional high-power VECSEL-to-diamond device with a modified Ag-In transient liquid phase (TLP) bonding technology. The post-bonding quality of VECSEL epitaxial membrane was thoroughly examined with scanning electron microscopy (SEM), focus ion beam (FIB) and high resolution high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). Owing to the low-temperature process, thermal-activated diffusion and thermo-mechanical stress have been suppressed to the minimal level within the epitaxial layers while optimizing the heat-spreading capability of the diamond. Interestingly, with experimental and thermodynamic evidences, a distinct nanostructure from spinodal decomposition has been discovered in the Ag-In bonding layer for the first time, whose structural feature is beneficial to the reliability of a VECSEL-to-diamond device. Conceptually, this work opens a new bonding technology category, i.e., Ag-In spinodal bonding.
{"title":"Low Temperature VECSEL-to-Diamond Heterogeneous Integration with Ag-In Spinodal Nanostructured Layer","authors":"Roozbeh Sheikhi, Yongjun Huo, F. Shi, Chin C. Lee","doi":"10.2139/ssrn.3708664","DOIUrl":"https://doi.org/10.2139/ssrn.3708664","url":null,"abstract":"Abstract Low temperature heterogeneous integration with diamond is the key technology in pushing upwards the high-power limit of a vertically-external-cavity surface-emitting laser (VECSEL). This work successfully accomplished a functional high-power VECSEL-to-diamond device with a modified Ag-In transient liquid phase (TLP) bonding technology. The post-bonding quality of VECSEL epitaxial membrane was thoroughly examined with scanning electron microscopy (SEM), focus ion beam (FIB) and high resolution high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). Owing to the low-temperature process, thermal-activated diffusion and thermo-mechanical stress have been suppressed to the minimal level within the epitaxial layers while optimizing the heat-spreading capability of the diamond. Interestingly, with experimental and thermodynamic evidences, a distinct nanostructure from spinodal decomposition has been discovered in the Ag-In bonding layer for the first time, whose structural feature is beneficial to the reliability of a VECSEL-to-diamond device. Conceptually, this work opens a new bonding technology category, i.e., Ag-In spinodal bonding.","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81717105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xing Gong, Congying Xiang, T. Auger, Jiajun Chen, Xiaocong Liang, Zhiyang Yu, M. Short, M. Song, Yuan Yin
Abstract This paper reports a new liquid metal embrittlement (LME) system in which a dual-phase Al0.7CoCrFeNi (equimolar fraction) high-entropy alloy (HEA) is embrittled by lead-bismuth eutectic (LBE) at 350 and 500°C. At 350°C, (Ni, Al)-rich BCC phase is embrittled, leading to intragrain cracking within this phase, while the predominant cracking mode changes to BCC/FCC phase boundary decohesion at 500°C. At both temperatures, cracks are rarely seen in the (Co, Cr, Fe)-rich FCC phase, indicating that this phase is immune to LME. Furthermore, the results suggest a transition from an adsorption-dominated LME mechanism at 350°C to a phase boundary wetting-dominated LME mechanism at 500°C.
{"title":"Liquid Metal Embrittlement of a Dual-Phase Al 0.7CoCrFeNi High-Entropy Alloy Exposed to Oxygen-Saturated Lead-Bismuth Eutectic","authors":"Xing Gong, Congying Xiang, T. Auger, Jiajun Chen, Xiaocong Liang, Zhiyang Yu, M. Short, M. Song, Yuan Yin","doi":"10.2139/ssrn.3711237","DOIUrl":"https://doi.org/10.2139/ssrn.3711237","url":null,"abstract":"Abstract This paper reports a new liquid metal embrittlement (LME) system in which a dual-phase Al0.7CoCrFeNi (equimolar fraction) high-entropy alloy (HEA) is embrittled by lead-bismuth eutectic (LBE) at 350 and 500°C. At 350°C, (Ni, Al)-rich BCC phase is embrittled, leading to intragrain cracking within this phase, while the predominant cracking mode changes to BCC/FCC phase boundary decohesion at 500°C. At both temperatures, cracks are rarely seen in the (Co, Cr, Fe)-rich FCC phase, indicating that this phase is immune to LME. Furthermore, the results suggest a transition from an adsorption-dominated LME mechanism at 350°C to a phase boundary wetting-dominated LME mechanism at 500°C.","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90698993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Navier-Stokes problem asks for a proof for fundamental smoothness in fluid dynamics. Fluently flying forward, this Essay solves the problem, proving fundamental smoothness. The solution draws on two principles of quantum fluid mechanics, matrix gradients and wave theory.
{"title":"A Proof for Navier-Stokes Smoothness","authors":"Brian R. Haney","doi":"10.2139/ssrn.3801362","DOIUrl":"https://doi.org/10.2139/ssrn.3801362","url":null,"abstract":"The Navier-Stokes problem asks for a proof for fundamental smoothness in fluid dynamics. Fluently flying forward, this Essay solves the problem, proving fundamental smoothness. The solution draws on two principles of quantum fluid mechanics, matrix gradients and wave theory.","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"77 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74520119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. Molnárová, O. Tyc, L. Heller, H. Seiner, P. Šittner
A novel experimental method allowing for 3D reconstruction of martensite variant microstructures evolving during tensile thermomechanical loading test on nanocrystalline NiTi wire is introduced. The method is based on the determination of the location, size and orientation of all martensite variants and interfaces within a selected polycrystal grain using post mortem selected area electron diffraction with dark field image analysis in TEM. It is found that martensitic microstructures in grains of nanocrystalline NiTi wire evolving during tensile thermomechanical loading tests (involve martensite reorientation, stress induced martensitic transformation and plastic deformation of martensite) are rather different than currently assumed in the SMA field. Martensitic microstructures in the NiTi wire deformed up to the end of reorientation (transformation) plateau up to ~7% strain at room temperature (100 °C), respectively, were found to contain single domain (001) compound twinned martensite filling whole grains. This was rationalized by the theoretical treatment of strain accommodation in grains of the fiber textured NiTi wire deformed in tension predicting such singular microstructural state for NiTi wire deformed up to 6.74% strain. Upon reverse martensitic subsequent stress free heating above the Af temperature, this martensitic microstructure retransforms back to the parent austenite yielding recoverable strains typical for NiTi (~6%) accompanied by very small unrecovered strain (~0.6%- 1.5% depending on the test temperature). On further tensile loading up to 15% strain, plastic deformation of oriented martensite starts by coordinated (100) and (201‾) deformation 1 twinning in martensite assisted by [1 0 0](0 0 1) dislocation slip giving rise to characteristic wedge type martensitic microstructure. Upon subsequent stress free heating above the Af temperature, this martensitic microstructure transforms to twinned austenitic microstructure yielding large recoverable strains (~10%) accompanied by large unrecovered strains (~5%). The dislocation slip assisted (100) and (201‾) deformation twinning in martensite renders NiTi excellent combination of strength and deformability and leads to refinement of austenitic microstructure accomplished via introducing {114} austenite twins into it.
{"title":"3D Reconstruction of Martensitic Microstructures in Grains of Deformed Nanocrystalline NiTi Wires by TEM","authors":"O. Molnárová, O. Tyc, L. Heller, H. Seiner, P. Šittner","doi":"10.2139/ssrn.3797420","DOIUrl":"https://doi.org/10.2139/ssrn.3797420","url":null,"abstract":"A novel experimental method allowing for 3D reconstruction of martensite variant microstructures evolving during tensile thermomechanical loading test on nanocrystalline NiTi wire is introduced. The method is based on the determination of the location, size and orientation of all martensite variants and interfaces within a selected polycrystal grain using post mortem selected area electron diffraction with dark field image analysis in TEM. It is found that martensitic microstructures in grains of nanocrystalline NiTi wire evolving during tensile thermomechanical loading tests (involve martensite reorientation, stress induced martensitic transformation and plastic deformation of martensite) are rather different than currently assumed in the SMA field. \u0000 \u0000Martensitic microstructures in the NiTi wire deformed up to the end of reorientation (transformation) plateau up to ~7% strain at room temperature (100 °C), respectively, were found to contain single domain (001) compound twinned martensite filling whole grains. This was rationalized by the theoretical treatment of strain accommodation in grains of the fiber textured NiTi wire deformed in tension predicting such singular microstructural state for NiTi wire deformed up to 6.74% strain. Upon reverse martensitic subsequent stress free heating above the Af temperature, this martensitic microstructure retransforms back to the parent austenite yielding recoverable strains typical for NiTi (~6%) accompanied by very small unrecovered strain (~0.6%- 1.5% depending on the test temperature). \u0000 \u0000On further tensile loading up to 15% strain, plastic deformation of oriented martensite starts by coordinated (100) and (201‾) deformation 1 twinning in martensite assisted by [1 0 0](0 0 1) dislocation slip giving rise to characteristic wedge type martensitic microstructure. Upon subsequent stress free heating above the Af temperature, this martensitic microstructure transforms to twinned austenitic microstructure yielding large recoverable strains (~10%) accompanied by large unrecovered strains (~5%). The dislocation slip assisted (100) and (201‾) deformation twinning in martensite renders NiTi excellent combination of strength and deformability and leads to refinement of austenitic microstructure accomplished via introducing {114} austenite twins into it.","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"50 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88998446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gaku Okuma, R. Miyaki, Kan Shinobe, A. Sciazko, Takaaki Shimura, Zilin Yan, S. Hara, T. Ogashiwa, N. Shikazono, F. Wakai
The anisotropic microstructure develops during powder processing and constrained sintering. In the present study, the microstructural evolutions of Au submicron particles during free sintering and constrained sintering were investigated by FIB-SEM tomography. The decrease in total surface area and the coarsening, i.e. the increase of mean intercept length of solid phase, were observed during the densification process. The anisotropic packing structure of spherical particles induced by casting process was characterized by area weighted fabric tensor, which represented the bond orientation and the anisotropy in contact area. In free sintering, the initial anisotropy in packing structure decreased with densification as indicated by the decrease in deviatoric component of surface energy tensor. In constrained sintering, the initial anisotropy observed by the mean intercept length of pore was reversed in the later stage. The microstructure evolved so as to form the elongated pores along the thickness direction.
{"title":"Anisotropic Microstructural Evolution and Coarsening in Free Sintering and Constrained Sintering of Metal Film by Using FIB-SEM Tomography","authors":"Gaku Okuma, R. Miyaki, Kan Shinobe, A. Sciazko, Takaaki Shimura, Zilin Yan, S. Hara, T. Ogashiwa, N. Shikazono, F. Wakai","doi":"10.2139/ssrn.3797423","DOIUrl":"https://doi.org/10.2139/ssrn.3797423","url":null,"abstract":"The anisotropic microstructure develops during powder processing and constrained sintering. In the present study, the microstructural evolutions of Au submicron particles during free sintering and constrained sintering were investigated by FIB-SEM tomography. The decrease in total surface area and the coarsening, i.e. the increase of mean intercept length of solid phase, were observed during the densification process. The anisotropic packing structure of spherical particles induced by casting process was characterized by area weighted fabric tensor, which represented the bond orientation and the anisotropy in contact area. In free sintering, the initial anisotropy in packing structure decreased with densification as indicated by the decrease in deviatoric component of surface energy tensor. In constrained sintering, the initial anisotropy observed by the mean intercept length of pore was reversed in the later stage. The microstructure evolved so as to form the elongated pores along the thickness direction.","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90146545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-26DOI: 10.15587/1729-4061.2021.225501
V. Kvasnikov, D. Ornatskyi, M. Graf, O. Shelukha
This paper addresses the issue of developing a computerized system for processing information in the construction of the trajectory of an unmanned aircraft vehicle (UAV), a remotely-piloted aviation system (RPAS), or another robotic system. Resolving this task involves the neural network learning algorithms based on the mathematical model of movement.
The construction of such a trajectory between two specified destinations has been considered that provides for the possibility of bypassing static and dynamic obstacles. The specified trajectory is divided into several smaller parts. The possibility of restructuring when changing the position of obstacles in space has been considered. A UAV flight control algorithm has been developed, which implies training a neural network for bypassing obstacles of different sizes.
To predict the development of the situation when an object moves between two specified points in space, it is proposed to use the Q-Learning algorithm. It has been shown that the smallest number of steps required for moving along a specified trajectory is 18, the largest is 273 steps. In case of distortion during data transmission, the training of the neural network makes it possible to reduce the possibility of collision with obstacles by improving the accuracy and speed of information transfer between the on-board computer and operator. A system of the video support to moving objects was modeled; dependence charts of the normalized frame size at different parameter values were built. Using the charts makes it possible to determine the function of the maneuver intensity. Existing neural network learning methods such as CNN and LSTM were compared. It has been proven that the success rate reaches 74 % when using CNN only, while it amounts to 92 % at the hybrid application of CNN+LSTM. The simulation results have demonstrated the high efficiency of the developed algorithm.
{"title":"Designing a Computerized Information Processing System to Build a Movement Trajectory of An Unmanned Aircraft Vehicle","authors":"V. Kvasnikov, D. Ornatskyi, M. Graf, O. Shelukha","doi":"10.15587/1729-4061.2021.225501","DOIUrl":"https://doi.org/10.15587/1729-4061.2021.225501","url":null,"abstract":"This paper addresses the issue of developing a computerized system for processing information in the construction of the trajectory of an unmanned aircraft vehicle (UAV), a remotely-piloted aviation system (RPAS), or another robotic system. Resolving this task involves the neural network learning algorithms based on the mathematical model of movement.<br><br>The construction of such a trajectory between two specified destinations has been considered that provides for the possibility of bypassing static and dynamic obstacles. The specified trajectory is divided into several smaller parts. The possibility of restructuring when changing the position of obstacles in space has been considered. A UAV flight control algorithm has been developed, which implies training a neural network for bypassing obstacles of different sizes.<br><br>To predict the development of the situation when an object moves between two specified points in space, it is proposed to use the Q-Learning algorithm. It has been shown that the smallest number of steps required for moving along a specified trajectory is 18, the largest is 273 steps. In case of distortion during data transmission, the training of the neural network makes it possible to reduce the possibility of collision with obstacles by improving the accuracy and speed of information transfer between the on-board computer and operator. A system of the video support to moving objects was modeled; dependence charts of the normalized frame size at different parameter values were built. Using the charts makes it possible to determine the function of the maneuver intensity. Existing neural network learning methods such as CNN and LSTM were compared. It has been proven that the success rate reaches 74 % when using CNN only, while it amounts to 92 % at the hybrid application of CNN+LSTM. The simulation results have demonstrated the high efficiency of the developed algorithm.","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"65 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81521660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-25DOI: 10.20998/2074-272x.2021.1.04
V. Lebedev
Goal. Refinement of the methodology for the development of an effective control system for an electric drive with controlled relay-type regulators for organizing a metered feed of an electrode wire using the parameters of the arc process with the possibility of using it in design practice and practice of technological application. Methodology. The proposed method for the mathematical description (mathematical model) of the system of the developed structure electric drive - arc process with current feedback of welding with a variable structure device is based on the theory of automatic control as applied to nonlinear elements, the application of the theory of operational calculus. At the same time, a selection and description of a nonlinear node in the feedback circuit in the form of a relay element with a certain structure and subsequent linearization of this element was made. As an electric motor of the electrode wire feeder, a new development of a specialized valve electric motor is used, which is used in the system with a microprocessor controller. Results. Due to the presence of a substantially nonlinear link, the calculation of the valve electric drive system – the arc process can be found on the basis of a system of nonlinear differential equations, which is practically impossible for practical application. In this work, these complications are overcome on the basis of a rational choice of the description of the nonlinear link, its harmonic linearization and obtaining on this basis a mathematical description of the system, from which, using the methodology of operational calculus, the relations necessary for calculating the parameters of the system are determined in analytical form. Originality. The problem of calculating a rather complex problem of mathematical description of the valve electric drive system – a technological link in the form of an arc process with a substantially nonlinear link in the feedback circuit in the work is solved with the effective use of a set of methodological methods, which include as a means of representing individual links, including nonlinear links selected simplifications and solutions of the obtained differential equations using original methods of operational calculus. The proposed method (mathematical model) is tested in two directions – oscillography of a real system, as well as system simulation. Practical significance. Using the developed methods for describing the control system, it is possible to calculate its characteristics and, on their basis, select the parameters for setting the electric drive controller, which allows, without additional experimental research, to obtain the necessary character of the transfer of electrode metal, and, consequently, the quality of the result of the arc process.
{"title":"On the Solution of the Problem of Synthesis of the Control System for the Process of Dosed Feed of Electrode Wire for Arc Welding Equipment","authors":"V. Lebedev","doi":"10.20998/2074-272x.2021.1.04","DOIUrl":"https://doi.org/10.20998/2074-272x.2021.1.04","url":null,"abstract":"Goal. Refinement of the methodology for the development of an effective control system for an electric drive with controlled relay-type regulators for organizing a metered feed of an electrode wire using the parameters of the arc process with the possibility of using it in design practice and practice of technological application. Methodology. The proposed method for the mathematical description (mathematical model) of the system of the developed structure electric drive - arc process with current feedback of welding with a variable structure device is based on the theory of automatic control as applied to nonlinear elements, the application of the theory of operational calculus. At the same time, a selection and description of a nonlinear node in the feedback circuit in the form of a relay element with a certain structure and subsequent linearization of this element was made. As an electric motor of the electrode wire feeder, a new development of a specialized valve electric motor is used, which is used in the system with a microprocessor controller. Results. Due to the presence of a substantially nonlinear link, the calculation of the valve electric drive system – the arc process can be found on the basis of a system of nonlinear differential equations, which is practically impossible for practical application. In this work, these complications are overcome on the basis of a rational choice of the description of the nonlinear link, its harmonic linearization and obtaining on this basis a mathematical description of the system, from which, using the methodology of operational calculus, the relations necessary for calculating the parameters of the system are determined in analytical form. Originality. The problem of calculating a rather complex problem of mathematical description of the valve electric drive system – a technological link in the form of an arc process with a substantially nonlinear link in the feedback circuit in the work is solved with the effective use of a set of methodological methods, which include as a means of representing individual links, including nonlinear links selected simplifications and solutions of the obtained differential equations using original methods of operational calculus. The proposed method (mathematical model) is tested in two directions – oscillography of a real system, as well as system simulation. Practical significance. Using the developed methods for describing the control system, it is possible to calculate its characteristics and, on their basis, select the parameters for setting the electric drive controller, which allows, without additional experimental research, to obtain the necessary character of the transfer of electrode metal, and, consequently, the quality of the result of the arc process.<br><br>","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81811611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-22DOI: 10.15587/1729-4061.2021.225117
I. Galych, R. Antoshchenkov, V. Antoshchenkov, Igor Lukjanov, S. Diundik, Oleksandr Kis
Results of theoretical studies of dynamics of the machine-tractor assembly taking into account the influence of a bearing surface profile were presented. It was established that in the course of operation, the machine-tractor assembly is exposed to a number of external factors leading to a change of vertical loads on the chassis and the engine. Mathematical models of dynamics of a tractor and a machine and a tractor unit consisting of a tractor of pivotally connected arrangement and a trailed sower were constructed. Such models make it possible to study dynamics and oscillatory processes of multi-element units. A mathematical model of tractor wheel dynamics was formed. Speeds and angles of orientation of elements of the machine-tractor assembly in space were determined. Influence of profile of the bearing surface on the unit elements when moving in the field prepared for sowing and the field after plowing was calculated. Theoretical studies of the influence of the bearing surface profile on dynamics of the machine-tractor assembly were performed on the example of KhTZ-242K tractor and Vega-8 Profi sower (Ukraine). When moving, the sower frame has a smaller amplitude of vibration accelerations than that of the tractor. Accordingly, the tractor has higher oscillation energy because it rests on the ground through its wheels having appropriate stiffness. The sower moves with its working bodies immersed into the soil which leads to a decrease in the amplitude of oscillations. The highest energy of amplitude of oscillation accelerations of the sower frame in the vertical direction was observed at frequencies of 15.9; 23.44; 35.3 and 42.87 Hz. It was found that the increase in working speeds of agricultural units leads to the fact that oscillations of all components reach significant values. This entails an increase in dynamic loads on soil and, as a consequence, its compaction
{"title":"Estimating the Dynamics of a Machine-Tractor Assembly Considering the Effect of the Supporting Surface Profile","authors":"I. Galych, R. Antoshchenkov, V. Antoshchenkov, Igor Lukjanov, S. Diundik, Oleksandr Kis","doi":"10.15587/1729-4061.2021.225117","DOIUrl":"https://doi.org/10.15587/1729-4061.2021.225117","url":null,"abstract":"Results of theoretical studies of dynamics of the machine-tractor assembly taking into account the influence of a bearing surface profile were presented. It was established that in the course of operation, the machine-tractor assembly is exposed to a number of external factors leading to a change of vertical loads on the chassis and the engine. Mathematical models of dynamics of a tractor and a machine and a tractor unit consisting of a tractor of pivotally connected arrangement and a trailed sower were constructed. Such models make it possible to study dynamics and oscillatory processes of multi-element units. A mathematical model of tractor wheel dynamics was formed. Speeds and angles of orientation of elements of the machine-tractor assembly in space were determined. Influence of profile of the bearing surface on the unit elements when moving in the field prepared for sowing and the field after plowing was calculated. Theoretical studies of the influence of the bearing surface profile on dynamics of the machine-tractor assembly were performed on the example of KhTZ-242K tractor and Vega-8 Profi sower (Ukraine). When moving, the sower frame has a smaller amplitude of vibration accelerations than that of the tractor. Accordingly, the tractor has higher oscillation energy because it rests on the ground through its wheels having appropriate stiffness. The sower moves with its working bodies immersed into the soil which leads to a decrease in the amplitude of oscillations. The highest energy of amplitude of oscillation accelerations of the sower frame in the vertical direction was observed at frequencies of 15.9; 23.44; 35.3 and 42.87 Hz. It was found that the increase in working speeds of agricultural units leads to the fact that oscillations of all components reach significant values. This entails an increase in dynamic loads on soil and, as a consequence, its compaction","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82128419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Monitoring and controlling Additive Manufacturing (AM) processes play a critical role in enabling the production of quality parts. AM processes generate large volumes of structured and unstructured in-situ measurement data. The ability to analyze this volume and variety of data in real-time is necessary for effective closed-loop control and decision-making. Existing control architectures are unable to handle this level of data volume and speed. This paper investigates the functional and computational requirements for real-time closed-loop AM process control. The paper uses those requirements to propose a function architecture for AM process monitoring and control. That architecture leads to a fog-computing solution to address the big data and real-time control challenges.
{"title":"Application of the Fog Computing Paradigm to Additive Manufacturing Process Monitoring and Control","authors":"Muhammad Adnan, Yan Lu, Albert T. Jones, F. Cheng","doi":"10.2139/ssrn.3785854","DOIUrl":"https://doi.org/10.2139/ssrn.3785854","url":null,"abstract":"Monitoring and controlling Additive Manufacturing (AM) processes play a critical role in enabling the production of quality parts. AM processes generate large volumes of structured and unstructured in-situ measurement data. The ability to analyze this volume and variety of data in real-time is necessary for effective closed-loop control and decision-making. Existing control architectures are unable to handle this level of data volume and speed. This paper investigates the functional and computational requirements for real-time closed-loop AM process control. The paper uses those requirements to propose a function architecture for AM process monitoring and control. That architecture leads to a fog-computing solution to address the big data and real-time control challenges.","PeriodicalId":18255,"journal":{"name":"MatSciRN: Process & Device Modeling (Topic)","volume":"237 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76300478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：