Ändra sökning
Avgränsa sökresultatet
1 - 17 av 17
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1.
    Holmberg, Jonas
    et al.
    Swerea IVF AB, Argongatan 30, Mölndal SE-431 53, Sweden; Department of Engineering Science, University West, Trollhättan SE-461 86, Sweden.
    Rodríguez Prieto, Juan Manuel
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Berglund, Johan
    Swerea IVF AB, Argongatan 30, Mölndal SE-431 53, Sweden.
    Sveboda, Ales
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Jonsén, Pär
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Experimental and PFEM-simulations of residual stresses from turning tests of a cylindrical Ti-6Al-4V shaft2018Ingår i: Procedia CIRP, ISSN 2212-8271, E-ISSN 2212-8271, Vol. 71, s. 144-149Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Alloy Ti-6Al-4V is a frequently used material in aero space applications due the high strength and low weight. This material is however often considered as a difficult to machine alloy due to several material properties such as the inherent characteristics of high hot hardness and strength which is causing an increased deformation of the cutting tool during machining. The thermal properties also cause a low thermal diffusion from locally high temperatures in the cutting zone that allows for reaction to the tool material resulting in increased tool wear.

    Predicting the behavior of machining of this alloy is therefore essential when selecting machining tools or machining strategies. If the surface integrity is predicted, the influence of different machining parameters could be studied using Particle Finite Element (PFEM)-simulations. In this investigation the influence from cutting speed and feed during turning on the residual stresses has been measured using x-ray diffraction and compared to PFEM-simulations.

    The results showed that cutting speed and feed have great impact on the residual stress state. The measured cutting force showed a strong correlation especially to the cutting feed. The microstructure, observed in SEM, showed highly deformed grains at the surface from the impact of the turning operation and the full width half maximum from the XDR measurements distinguish a clear impact from different cutting speed and feed which differed most for the higher feed rate.

    The experimental measurements of the residual stresses and the PFEM simulations did however not correlate. The surface stresses as well as the sign of the residuals stresses differed which might be due to the material model used and the assumption of using a Coulomb friction model that might not represent the cutting conditions in the investigated case.

    Ladda ner fulltext (pdf)
    fulltext
  • 2.
    Larsson, Simon
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Carbonell, Josep Maria
    Centre Internacional de Mètodes Numèrics en Enginyeria (CIMNE) Universitat Politècnica de Catalunya (UPC).
    Rodriguez Prieto, Juan Manuel
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Gustafsson, Gustaf
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Jonsén, Pär
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Häggblad, Hans-åke
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Celigueta, Miquel Angel
    Centre Internacional de Mètodes Numèrics en Enginyeria (CIMNE) Universitat Politècnica de Catalunya (UPC).
    Latorre, Salvador
    Centre Internacional de Mètodes Numèrics en Enginyeria (CIMNE) Universitat Politècnica de Catalunya (UPC).
    Numerical simulation and validation of powder filling using particle based methods2017Ingår i: PARTICLES 2017, 2017Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Powder pressing is a complicated process as the mechanical behaviour of the powder material changes with increasing density. Manufacturers tend to produce components with shapes of increasing complexity requiring improved pressing equipment and methods. Mechanical properties of powder materials changes dramatically from the beginning to the end of the compaction phase. Previous investigations have shown that powder transfer and large powder flow during filling affects the strength of the final component significantly. Combined experimental and numerical studies can improve the understanding of the impact the filling stage has on the final component, e.g. to explain the non-homogeneity of the density of powder pressed parts.This work covers numerical modelling and simulation of powder filling using two different approaches, the discrete element method (DEM) [1,2] which is a micro mechanical based method and the particle finite element method (PFEM) [3] which is a continuum based method. Experimental measurements with digital speckle photography (DSP) [4] from a previous study [5] are used to validate the numerical simulations. The numerical results are compared in terms of agreement with the experimental results, such as velocity- and strain field data. The numerical simulations are further compared in terms of computational efficiency.The comparison of DSP measurements and simulations gives similar flow characteristics. In conclusion, experimental measurements with DSP together with numerical simulation are powerful tools to increase the knowledge of powder filling and also to improve the numerical model prediction. Improved numerical models will facilitate future product development processes and decrease the lead time.

    Ladda ner fulltext (pdf)
    fulltext
  • 3.
    Larsson, Simon
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Hållfasthetslära.
    Rodriguez Prieto, Juan Manuel
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik. Mechanical Engineering Department, EAFIT University, Medellín, Colombia.
    Gustafsson, Gustaf
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Häggblad, Hans-Åke
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Hållfasthetslära.
    Jonsén, Pär
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Hållfasthetslära.
    The particle finite element method for transient granular material flow: modelling and validation2021Ingår i: Computational Particle Mechanics, ISSN 2196-4378, Vol. 8, nr 1, s. 135-155Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The prediction of transient granular material flow is of fundamental industrial importance. The potential of using numerical methods in system design for increasing the operating efficiency of industrial processes involving granular material flow is huge. In the present study, a numerical tool for modelling dense transient granular material flow is presented and validated against experiments. The granular materials are modelled as continuous materials using two different constitutive models. The choice of constitutive models is made with the aim to predict the mechanical behaviour of a granular material during the transition from stationary to flowing and back to stationary state. The particle finite element method (PFEM) is employed as a numerical tool to simulate the transient granular material flow. Use of the PFEM enables a robust treatment of large deformations and free surfaces. The fundamental problem of collapsing rectangular columns of granular material is studied experimentally employing a novel approach for in-plane velocity measurements by digital image correlation. The proposed numerical model is used to simulate the experimentally studied column collapses. The model prediction of the in-plane velocity field during the collapse agrees well with experiments.

    Ladda ner fulltext (pdf)
    fulltext
  • 4.
    Rodriguez, Juan Manuel
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Carbonell, Josep Maria
    International Center for Numerical Methods in Engineering (CIMNE), Campus Nord UPC, Gran Capitán, s/n., 08034 Barcelona.
    Cante, J.C.
    Escola Tècnica Superior d’Enginyeries Industrial i Aeronàutica de Terrassa.
    Oliver, J.
    International Center for Numerical Methods in Engineering (CIMNE), Campus Nord UPC, Gran Capitán, s/n., 08034 Barcelona.
    Continuous chip formation in metal cutting processes using the Particle Finite Element Method (PFEM)2017Ingår i: International Journal of Solids and Structures, ISSN 0020-7683, E-ISSN 1879-2146, Vol. 120, s. 81-102Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents a study on the metal cutting simulation with a particular numerical technique, the Particle Finite Element Method (PFEM) with a new modified time integration algorithm and incorporating a contact algorithm capability . The goal is to reproduce the formation of continuous chip in orthogonal machining. The paper tells how metal cutting processes can be modelled with the PFEM and which new tools have been developed to provide the proper capabilities for a successful modelling. The developed method allows for the treatment of large deformations and heat conduction, workpiece-tool contact including friction effects as well as the full thermo-mechanical coupling for contact. The difficulties associated with the distortion of the mesh in areas with high deformation are solved introducing new improvements in the continuous Delaunay triangulation of the particles. The employment of adaptative insertion and removal of particles at every new updated configuration improves the mesh quality allowing for resolution of finer-scale features of the solution. The performance of the method is studied with a set of different two-dimensional tests of orthogonal machining. The examples consider, from the most simple case to the most complex case, different assumptions for the cutting conditions and different material properties. The results have been compared with experimental tests showing a good competitiveness of the PFEM in comparison with other available simulation tools.

  • 5.
    Rodriguez, Juan Manuel
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Jonsén, Pär
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Svoboda, Ales
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Dislocation Density Based Material Model Applied in PFEM-simulation of Metal Cutting2017Ingår i: Procedia CIRP, ISSN 2212-8271, E-ISSN 2212-8271, Vol. 58, s. 193-197Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Metal cutting is one of the most common metal-shaping processes. In this process, specified geometrical and surface properties are obtained through the break-up and removal of material by a cutting edge into a chip. The chip formation is associated with large strains, high strain rates and locally high temperatures due to adiabatic heating. These phenomena together with numerical complications make modeling of metal cutting challenging. Material models, which are crucial in metal-cutting simulations, are usually calibrated against data from material testing. Nevertheless, the magnitudes of strains and strain rates involved in metal cutting are several orders of magnitude higher than those generated from conventional material testing. Therefore, a highly desirable feature is a material model that can be extrapolated outside the calibration range. In this study, a physically based plasticity model based on dislocation density and vacancy concentration is used to simulate orthogonal metal cutting of AISI 316L. The material model is implemented into an in-house particle finite-element method software. Numerical simulations are in agreement with experimental results for different cutting speed and feed.

  • 6.
    Rodriguez Prieto, Juan Manuel
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Carbonell, J. M.
    International Center for Numerical Methods in Engineering (CIMNE), Barcelona, Spain.
    Cante, J.C.
    Escola Tècnica Superior d’Enginyeries Industrial i Aeronàutica de Terrassa; International Center for Numerical Methods in Engineering (CIMNE), Barcelona, Spain.
    Oliver, J.
    E.T.S dEnginyers de Camins, Canals i Ports, Technical University of Catalonia (BarcelonaTech), Barcelona, Spain. International Center for Numerical Methods in Engineering (CIMNE), Barcelona, Spain.
    Jonsén, Pär
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Generation of segmental chips in metal cutting modeled with the PFEM2018Ingår i: Computational Mechanics, ISSN 0178-7675, E-ISSN 1432-0924, Vol. 61, nr 6, s. 639-655Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Particle Finite Element Method, a lagrangian finite element method based on a continuous Delaunay re-triangulation of the domain, is used to study machining of Ti6Al4V. In this work the method is revised and applied to study the influence of the cutting speed on the cutting force and the chip formation process. A parametric methodology for the detection and treatment of the rigid tool contact is presented. The adaptive insertion and removal of particles are developed and employed in order to sidestep the difficulties associated with mesh distortion, shear localization as well as for resolving the fine-scale features of the solution. The performance of PFEM is studied with a set of different two-dimensional orthogonal cutting tests. It is shown that, despite its Lagrangian nature, the proposed combined finite element-particle method is well suited for large deformation metal cutting problems with continuous chip and serrated chip formation.

  • 7.
    Rodriguez Prieto, Juan Manuel
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Carbonell, J.M
    International Center for Numerical Methods in Engineering (CIMNE), Campus Nord UPC, Barcelona, Spain.
    Jonsén, Pär
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Numerical Methods for the Modelling of Chip Formation2020Ingår i: Archives of Computational Methods in Engineering, ISSN 1134-3060, E-ISSN 1886-1784, Vol. 27, nr 2, s. 387-412Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The modeling of metal cutting has proved to be particularly complex due to the diversity of physical phenomena involved, including thermo-mechanical coupling, contact/friction and material failure. During the last few decades, there has been significant progress in the development of numerical methods for modeling machining operations. Furthermore, the most relevant techniques have been implemented in the relevant commercial codes creating tools for the engineers working in the design of processes and cutting devices. This paper presents a review on the numerical modeling methods and techniques used for the simulation of machining processes. The main purpose is to identify the strengths and weaknesses of each method and strategy developed up-to-now. Moreover the review covers the classical Finite Element Method covering mesh-less methods, particle-based methods and different possibilities of Eulerian and Lagrangian approaches.

  • 8.
    Rodriguez Prieto, Juan Manuel
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Jonsén, Pär
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Svoboda, Ales
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    A Particle Finite Element Method for Machining Simulations2016Ingår i: ECCOMAS Congress 2016: VII European Congress on Computational Methods in Applied Sciences and Engineering, Crete Island, Greece, 5–10 June 2016 / [ed] M. Papadrakakis; V. Papadopoulos; G. Stefanou; V. Plevris, Athens: National Technical University of Athens , 2016, Vol. 1, s. 539-553Konferensbidrag (Refereegranskat)
    Abstract [en]

    Metal cutting process is a nonlinear dynamic problem that includes geometrical, material, and contact nonlinearities. In this work a Lagrangian finite element approach for simulation of metal cutting processes is presented, based on the so-called Particle Finite Ele-ment Method (PFEM). The governing equations for the deformable bodies are discretized with the FEM via a mixed formulation using simplicial elements with equal linear interpolation for displacements, pressure and temperature. The use of PFEM for modeling of metal cutting pro-cesses includes the use of a remeshing process, α -shape concepts for detecting domain bound-aries, contact mechanics laws and material constitutive models. The merits of the formulation are demonstrated in the solution of 2D and 3D thermally-coupled metal cutting processes using the particle finite element method. The method shows good results and is a promising method for future simulations of thermally/coupled machining processes.

    Ladda ner fulltext (pdf)
    fulltext
  • 9.
    Rodriguez Prieto, Juan Manuel
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Jonsén, Pär
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Svoboda, Ales
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Numerical modeling of metal cutting processes using the particle finite element method (PFEM) and a physically based plasticity model2015Ingår i: Particle-based Methods IV: Fundamentals and Applications : Proceedings of the IVInternational Conference on Particle-Based Methods–Fundamentals and Applications held in Barcelona, Spain, 28-30September 2015 / [ed] E. Oñate; M. Bischoff; D.R.J. Owen; P. Wriggers; T. Zhodi, Barcelona: International Center for Numerical Methods in Engineering (CIMNE), 2015, s. 1066-1072Konferensbidrag (Refereegranskat)
    Abstract [en]

    Metal cutting is one of the most common metal shaping processes. Specified geometrical and surface properties are obtained by break-up of material and removal by a cutting edge into a chip. The chip formation is associated with large strain, high strain rate and locally high temperature due to adiabatic heating which make the modeling of cutting processes difficult. Furthermore, dissipative plastic and friction work generate high local temperatures. These phenomena together with numerical complications make modeling of metal cutting difficult. Material models, which are crucial in metal cutting simulations, are usually calibrated based on data from material testing. Nevertheless, the magnitude of strain and strain rate involved in metal cutting are several orders higher than those generated from conventional material testing. Therefore, a highly desirable feature is a material model that can be extrapolated outside the calibration range. In this study a physically based plasticity model based on dislocation density and vacancy concentration is used to simulate orthogonal metal cutting of AISI 316L. The material model is implemented into an in-house Particle Finite Element Method software. Numerical simulations are in agreement with experimental results, but also with previous results obtained with the finite element method.

    Ladda ner fulltext (pdf)
    fulltext
  • 10.
    Rodriguez Prieto, Juan Manuel
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Jonsén, Pär
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Svoboda, Ales
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    On the Numerical Modeling of Metal Forming Processes Using the Particle Finite Elementmethod2016Ingår i: Proceedings of 29th Nordic Seminar on Computational Mechanics – NSCM29 / [ed] Ragnar Larsson, Göteborg: Department of Applied Mechanics CHALMERS UNIVERSITY OF TECHNOLOGY Göteborg, Sweden 2016 , 2016, , s. 4Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this work a Lagrangian nite element approach for simulation of metalforming is presented, based on the so-called Particle Finite Element Method (PFEM). Thegoverning equations for the deformable bodies are discretized with the FEM via a mixedformulation using simplicial elements with equal linear interpolation for displacements,pressure and temperature. The use of PFEM for modeling of metal forming processesincludes the use of a remeshing process, -shape concepts for detecting domain boundaries,contact mechanics laws and material constitutive models. The merits of the formulationare demonstrated in the solution of 2D thermally coupled metal forming processes usingthe particle nite element method. The method shows good results and is a promisingmethod for future simulations of thermally/coupled forming processes.

    Ladda ner fulltext (pdf)
    fulltext
  • 11.
    Rodriguez Prieto, Juan Manuel
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Jonsén, Pär
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Svoboda, Ales
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Simulation of metal cutting using the particle finite-element method and a physically based plasticity model2017Ingår i: Computational Particle Mechanics, ISSN 2196-4378, Vol. 4, nr 1, s. 35-51Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Metal cutting is one of the most common metal-shaping processes. In this process, specified geometrical and surface properties are obtained through the break-up of material and removal by a cutting edge into a chip. The chip formation is associated with large strains, high strain rates and locally high temperatures due to adiabatic heating. These phenomena together with numerical complications make modeling of metal cutting difficult. Material models, which are crucial in metal-cutting simulations, are usually calibrated based on data from material testing. Nevertheless, the magnitudes of strains and strain rates involved in metal cutting are several orders of magnitude higher than those generated from conventional material testing. Therefore, a highly desirable feature is a material model that can be extrapolated outside the calibration range. In this study, a physically based plasticity model based on dislocation density and vacancy concentration is used to simulate orthogonal metal cutting of AISI 316L. The material model is implemented into an in-house particle finite-element method software. Numerical simulations are in agreement with experimental results, but also with previous results obtained with the finite-element method.

  • 12.
    Rodriguez Prieto, Juan Manuel
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Hållfasthetslära. Escuela de Ciencias Aplicadas e Ingeniería, Universidad EAFIT, Cra 49 n 7–sur–50, Medellín 050022, Colombia.
    Larsson, Simon
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Hållfasthetslära.
    Afrasiabi, Mohamadreza
    Data-Driven & Computational Manufacturing Group, Inspire AG, 8005 Zürich, Switzerland.
    Thermomechanical Simulation of Orthogonal Metal Cutting with PFEM and SPH Using a Temperature-Dependent Friction Coefficient: A Comparative Study2023Ingår i: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 16, nr 10, artikel-id 3702Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this work, we apply the Particle Finite Element Method (PFEM) and Smoothed Particle Hydrodynamics (SPH) to simulate the orthogonal cutting chip formation of two workpiece materials, i.e., AISI 1045 steel and Ti6Al4V titanium alloy. A modified Johnson–Cook constitutive model is used to model the plastic behavior of the two workpiece materials. No damage or strain softening is included in the model. The friction between the workpiece and the tool is modeled following Coulomb’s law with a temperature-dependent coefficient. The accuracy of PFEM and SPH in predicting thermomechanical loads at various cutting speeds and depths against the experimental data are compared. The results show that both numerical methods can predict the rake face temperature of AISI 1045 with errors less than 34%. For Ti6Al4V, however, the temperature prediction errors are significantly higher than those of the steel alloy. Errors in force prediction were in the range of 10% to 76% for both methods, which compare very well with those reported in the literature. This investigation infers that the Ti6Al4V behavior under machining conditions is difficult to model on the cutting scale irrespective of the choice of numerical method.

    Ladda ner fulltext (pdf)
    fulltext
  • 13.
    Rodríguez, Juan Manuel
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Jonsén, Pär
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Svoboda, Ales
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    A particle finite element method applied to modeling and simulation of machining processes2017Ingår i: Advanced Machining Processes: Innovative Modeling Techniques / [ed] Angelos P. Markopoulos, J. Paulo Davim, Boca Raton: CRC Press, 2017, 1 ed, s. 1-24Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    Metal cutting process is a nonlinear dynamic problem that includesgeometrical, material, and contact nonlinearities. In this work, aLagrangian finite element approach for the simulation of metal cuttingprocess is presented based on the so-called particle finite element method(PFEM). The governing equations for the deformable bodies are discretizedwith the finite element method (FEM) via a mixed formulationusing simplicial elements with equal linear interpolation for displacements,pressure, and temperature. The use of PFEM for modeling ofmetal cutting processes includes the use of a remeshing process, α-shapeconcepts for detecting domain boundaries, contact mechanics laws, andmaterial constitutive models. In this chapter, a 2D PFEM-based numericalmodeling of metal cutting processes has been studied to investigate theeffects of cutting velocity on tool forces, temperatures, and stresses inmachining of Ti–6Al–4V. The Johnson–Cook plasticity model is usedto describe the work material behavior. Numerical simulations are inagreement with experimental results.

  • 14.
    Rodríguez, Juan Manuel
    et al.
    EAFIT University, Medellin, Colombia.
    Larsson, Simon
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Carbonell, Josep Maria
    Centre Internacional de Mètodes Numèrics en Engninyeria (CIMNE), Barcelona, Spain.
    Jonsén, Pär
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Dislocation Density Based Flow Stress Model Applied to the PFEM Simulation of Orthogonal Cutting Processes of Ti-6Al-4V2020Ingår i: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 13, nr 8, artikel-id 1979Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Machining of metals is an essential operation in the manufacturing industry. Chip formation in metal cutting is associated with large plastic strains, large deformations, high strain rates and high temperatures, mainly located in the primary and in the secondary shear zones. During the last decades, there has been significant progress in numerical methods and constitutive modeling for machining operations. In this work, the Particle Finite Element Method (PFEM) together with a dislocation density (DD) constitutive model are introduced to simulate the machining of Ti-6Al-4V. The work includes a study of two constitutive models for the titanium material, the physically based plasticity DD model and the phenomenology based Johnson–Cook model. Both constitutive models were implemented into an in-house PFEM software and setup to simulate deformation behaviour of titanium Ti6Al4V during an orthogonal cutting process. Validation show that numerical and experimental results are in agreement for different cutting speeds and feeds. The dislocation density model, although it needs more thorough calibration, shows an excellent match with the results. This paper shows that the combination of PFEM together with a dislocation density constitutive model is an excellent candidate for future numerical simulations of mechanical cutting.

    Ladda ner fulltext (pdf)
    fulltext
  • 15.
    Sandin, Olle
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Hållfasthetslära.
    Rodriguez, Juan Manuel
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Hållfasthetslära. School of Applied Sciences and Engineering, EAFIT University, Carrera 49 No. 7 South-50, Medellín, Colombia.
    Larour, Patrick
    voestalpine Stahl GmbH, voestalpine-Straße 3, 4020, Linz, Austria.
    Parareda, Sergi
    Unit of Metallic and Ceramic Materials, Eurecat, Centre Tecnològic de Catalunya, Plaça de la Ciència, 2, 08243, Manresa, Spain.
    Frómeta, David
    Unit of Metallic and Ceramic Materials, Eurecat, Centre Tecnològic de Catalunya, Plaça de la Ciència, 2, 08243, Manresa, Spain.
    Hammarberg, Samuel
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Hållfasthetslära.
    Kajberg, Jörgen
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Hållfasthetslära.
    Casellas, Daniel
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Hållfasthetslära. Unit of Metallic and Ceramic Materials, Eurecat, Centre Tecnològic de Catalunya, Plaça de la Ciència, 2, 08243 Manresa, Spain.
    A particle finite element method approach to model shear cutting of high-strength steel sheets2024Ingår i: Computational Particle Mechanics, ISSN 2196-4378Artikel i tidskrift (Refereegranskat)
  • 16.
    Sandin, Olle
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Hållfasthetslära.
    Rodriguez Prieto, Juan Manuel
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Hållfasthetslära. School of Applied Sciences and Engineering, EAFIT University, Medellin, Colombia.
    Hammarberg, Samuel
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Hållfasthetslära.
    Casellas, Daniel
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Hållfasthetslära. Eurecat, Centre Tecnològic de Catalunya, Unit of Metallic and Ceramic Materials, Manresa, Spain .
    Numerical modelling of shear cutting using particle methods2023Ingår i: IOP Conference Series: Materials Science and Engineering / [ed] Nader Asnafi, Lars-Erik Lindgren, Institute of Physics (IOP), 2023, Vol. 1284, artikel-id 012048Konferensbidrag (Refereegranskat)
    Abstract [en]

    The use of Advanced High Strength Steel (AHSS) allows for lightweighting of sheet steel components, with maintained structural integrity of the part. However, AHSS grades show limitations in edge crack resistance, primarily influenced by sheared edge damage introduced by the shear cutting process. Numerical modelling of the shear cutting process can aid the understanding of the sheared edge damage, thus avoiding unforeseen edge cracking in the subsequent cold forming. However, the extreme deformations of the blank during the shear cutting process are likely to cause numerical instabilities and divergence using conventional Finite Element modelling. To overcome these challenges, this work presents the use of a particle-based numerical modelling method called the Particle Finite Element Method (PFEM). PFEM accurately solves some of the challenges encountered in shear cutting with the standard Finite Element method, such as large deformation, angular distortions, generation of new boundaries and presents an efficient way of transfer historical information from the old to the new mesh, minimising the results diffusion. The present work shows prediction of cut edge morphology of AHSS using a PFEM modelling scheme, where the numerical results are verified against experiments. With these results, the authors show new possibilities to obtain accurate numerical prediction of the shear cutting process, which promotes further advances in prediction of edge damaged related to shear cutting of AHSS.

    Ladda ner fulltext (pdf)
    fulltext
  • 17.
    Sridhar, Praveen
    et al.
    TU Kaiserslautern, Erwin-Schrödinger-Straße, D-67653 Kaiserslautern, Germany.
    Rodríguez Prieto, Juan Manuel
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Hållfasthetslära. Escuela de Ciencias Aplicadas e Ingeniería, Universidad EAFIT, Cra 49 n 7-sur-50, Medellín 050022, Colombia.
    de Payrebrune, Kristin M.
    TU Kaiserslautern, Erwin-Schrödinger-Straße, D-67653 Kaiserslautern, Germany.
    Modeling Grinding Processes-Mesh or Mesh-Free Methods, 2D or 3D Approach?2022Ingår i: Journal of Manufacturing and Materials Processing, E-ISSN 2504-4494, Vol. 6, nr 5, artikel-id 120Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The objectives of this study are mainly two: (1) to validate whether a single grain scratch process can be modeled in two dimensions under the assumption of plane strain, and (2) to select the best discretization approach to model a single grain scratch process. This paper first focuses on the simulation of the orthogonal cutting process (aluminum alloy A2024 T351) using two mesh-based discretization approaches, the pure Lagrangian method (LAG) and the arbitrary Lagrangian-Eulerian method (ALE), and two particle-based approaches, the particle finite element method (PFEM) and smooth particle hydrodynamics (SPH), for both positive and negative rake angles. Benchmarking of the orthogonal cutting models at a rake angle of gamma = 20 degrees is performed with the results of the process forces (cutting and passive forces) of a turning experiment from the literature. It is shown that all models are able to predict the cutting forces, but not the passive force. The orthogonal cutting model is further extended to simulate the cutting mechanism with negative rake tool geometries typically found in grinding and single grit scratching processes. The effects of the negative rake angles on the discretization approaches are studied. The calculated process forces are also compared to the measurements of the single grit scratch process performed at our laboratory. The 2D orthogonal cutting models significantly overestimate the process forces. One of the reasons why the orthogonal 2D cutting model is inadequate is that it cannot describe the complex mechanisms of material removal such as rubbing, plowing, and cutting. To account for these phenomena in LAG, ALE, and SPH discretization approaches, a 3D scratch model is developed. When comparing the process forces of the 3D model with the experimental measurements, all three discretization approaches show good agreement. However, it can be seen that the ALE model most closely matches the process forces with the experimental results. Finally, the ALE 3D scratch model was subjected to sensitivity analysis by changing the cutting speed, the depth of cut and the tool geometry. The results clearly show that the ALE method not only predicts the process forces and form the trends observed in the scratching experiments, but also predicts the scratch topography satisfactorily. Hence, we conclude that a 3D model is necessary to describe a scratch process and that the ALE method is the best discretization method.

1 - 17 av 17
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf