ON THE USE OF SMOOTHED PARTICLE HYDRODYNAMICS TO MODEL ORTHOGONAL MACHINING
1 online resource (84 pages) : PDF
University of North Carolina at Charlotte
Modeling machining processes with conventional finite element methods (FEM) is challenging due to the severe deformations that occur during machining, complex frictional conditions that exist between the cutting tool and the workpiece, and the possibility of self contact due to chip curling. Recently, the Smoothed Particle Hydrodynamics (SPH) method has emerged as a potential alternative for modeling machining processes due to its ability to handle severe deformations while avoiding mass and energy losses encountered by traditional FEM. The method has been implemented in several commercial finite element packages such as ABAQUS and LS-DYNA for solving problems involving localized severe deformations.The SPH method belongs to a class of numerical methods collectively known as meshless or mesh-free methods. In the SPH method, the given domain is discretized into a set of particles and the properties and field variables associated with each particle are obtained by taking into account the particles within its neighborhood defined by a smoothing length and a kernel function. The method employs several parameters for controlling the particle behavior during deformations and the accuracy of the solution depends on an optimal combination of these parameters. The three most important parameters are, the smoothing length, particle density, and the type of SPH formulation. In the present work, the effects of these parameters on the chip morphology, stress distribution and cutting force in the context of orthogonal machining of AISI 1045 steel are investigated. The LS-DYNA finite element package along with Johnson-Cook material model is used for this purpose. Results from the parametric study are presented and the accuracy of the solutions as compared with the results from conventional FEM are discussed. In addition, five different sets of values available in the literature are considered for the Johnson-Cook material model for AISI 1045 steel. The sensitivity of chip morphology and stress distribution on these material parameters is discussed.
FINITE ELEMENT ANALYSISJOHNSON-COOKLS-DYNAMESH FREE PARTICLE METHODSORTHOGONAL MACHININGSMOOTHED PARTICLE HYDRODYNAMICS
Tabarraei, AlirezaOgunro, Vincent
Thesis (M.S.)--University of North Carolina at Charlotte, 2014.
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