Ductile fracture presents challenges with respect to material modelling andnumerical simulations of localization. The strain and damage localization maybe unwanted as it indicates a failure in the process or, as in the case ofmachining and cutting, a wanted phenomenon to be controlled. The latterrequires a higher accuracy regarding the modelling of the underlying coupledplastic and fracturing/damage behaviour of the material, metal in the currentcontext as well as the stability and robustness of the simulation procedure.This aim of this work is to develop, evaluate and implement formulations thatcan efficiently and reliably handle localization problems in machiningsimulations. The focus is on non-local models. The non-local models extendthe standard continuum mechanics theory by using non-local continuumtheory in order to achieve mesh independent results when simulating fractureor shear localization.The non-local damage model is implemented and various formulations areevaluated in a Matlab™ based finite element code. The chosen algorithm wasthen implemented in commercial software. The implementations remedy themesh sensitivity problem and gives convergent solution for metal cuttingsimulations with reasonable cost. The length scale associated with the nonlocalmodels are in the current context considered as a numericalregularization parameter. The model has been applied in machiningsimulations and compared with measurements from industry.Keywords: Finite element simulation; Non-local damage; Plasticity; Machining / Godkänd; 2016; 20160222 (oluabi); Nedanstående person kommer att disputera för avläggande av teknologie doktorsexamen. Namn: Olufunminiyi Abiri Ämne: Materialmekanik/Material Mechanics Avhandling: Non-Local Models in Manufacturing Simulations Opponent: Professor Miguel Vaz, Dept Mechanical Engineering, State University of Santa Catarina, Joinville, Brazil. Ordförande: Professor Lars-Erik Lindgren, Avd för material- och solidmekanik, Institutionen för teknikvetenskap och matematik, Luleå tekniska universitet, Luleå. Tid: Fredag 22 april, 2016 kl 09.30 Plats: E231, Luleå tekniska universitet
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:ltu-16906 |
| Date | January 2016 |
| Creators | Abiri, Olufunminiyi |
| Publisher | Luleå tekniska universitet, Material- och solidmekanik |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Doctoral thesis, comprehensive summary, info:eu-repo/semantics/doctoralThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, 1402-1544 ; |
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