Papers by Keyword: Crystal Plasticity Finite Element Method

Abstract: In this study, texture evolution during high pressure torsion (HPT) of aluminum single crystal is predicted by the crystal plasticity finite element method (CPFEM) model integrating the crystal plasticity constitutive theory with Bassani & Wu hardening model. It has been found by the simulation that, during the HPT process, the lattice rotates mainly around the radial direction of the sample. With increasing HPT deformation, the initial cube orientation rotates progressively to the rotated cube orientation, and then to the C component of ideal torsion texture which could be remained over a wide strain range. Further HPT deformation leads to the orientation towards to the ideal texture component.

Abstract: By using Eulerian adaptive modeling approach, both the round extrusion and sheet extrusion of magnesium alloy AZ31 were simulated. Furthermore, the history strains of material point flowing through the Eulerian domain was extracted and used as the foundation for defining the boundary conditions in the crystal plasticity finite element (CPFE) modeling for the extrusion texture. By virtue of this modeling method, the realistic grain boundaries can be approximated by using a 3D polycrystal generator and the intra-granular interactions can be well described. Both of the simulated round extrusion and sheet extrusion textures of alloy AZ31 show reasonable agreement with experimental results.

Abstract: In the last decades, manufacturing of layered composite materials has become an interesting topic in industrial development. Joining properties of adhesively bonded materials are characterized by a complex interaction of plastic deformation, thermo-mechano-chemical coupling effects, adhesion and diffusion. Additionally, the interactions between the microstructures involved in the process have to be taken into account. In this paper the microstructure of materials (as e.g. Al1050, Al2024 and Al5754), which have a wide range of applications in engineering structures, is numerically and experimentally investigated. The results are compared with experimental data.

Abstract: Based on the rate-dependent crystal plasticity theory, the user material subroutine is embedded into the abaqus / standard, which is able to describe the changes of grain orientation. The crystal plasticity finite element method is used to simulate the aluminum single crystal uniaxial tension and the stress and strain response is analyzed under different tension displacement.

Abstract: The friction is a key factor that influences the surface quality in metal forming. To figure out the relationship between the friction and the surface roughening, a finite element model is employed in the commercial finite element software ABAQUS to simulate the surface roughness of top side of Al plate during uniaxial planar compression. With the change of friction conditions, the surface roughening varies. The average surface roughness (Ra) shows a relationship with the friction coefficient. During the surface roughening process, the grain slip takes place in the “soft orientation”, and the “hard orientations” become the barrier of the slip.

Abstract: The kinetics and microstructure evolution during static recrystallization (SRX) of hot-deformed austenite in a low carbon steel are simulated by coupling a cellular automaton (CA) model with a crystal plasticity finite element model (CPFEM). The initial deformed characteristics, which include the stored energy of deformation and the crystallographic orientation induced by a plane strain hot compression are simulated using a crystal plasticity finite element model. These data are mapped onto the CA regular lattices as the initial parameters for SRX simulation. The coupled simulation results reveal that the heterogeneous distribution of the stored energy of deformation results in non-uniform nucleation and a slower kinetics. The influence of non-uniform distribution in stored energy on the SRX kinetics and microstructure evolution is discussed based on a microstructural path (MP) analysis.

Abstract: The crystal plasticity finite element method (CPFEM) is probably the method with the best potential to directly incorporate crystal anisotropy and its evolution into forming simulations. However, when it comes to the simulation of bulk materials, the representation of the crystal orientation distribution function (ODF), i.e. of the statistical texture, within the CPFEM framework becomes a key issue for the efficiency of the approach. In this work two different approaches for sampling the ODF are compared. The first is the so called Texture-Component-CPFEM, where the discretisation is based on the representation of the ODF by texture components. The second approach is based on the representation of the ODF by series expansion and uses a direct mapping of the ODF represented in the form of C-coefficients to individual orientations as needed by the CPFEM. Both methods are compared using the textures of Aluminum hot band as well as cold rolled material.