AN INTEGRATED CRYSTAL PLASTICITY FE SYSTEM FOR MICROFORMING SIMULATION

2009 ◽  
Vol 01 (01) ◽  
pp. 107-124 ◽  
Author(s):  
J. CAO ◽  
W. ZHUANG ◽  
S. WANG ◽  
K. C. HO ◽  
N. ZHANG ◽  
...  
Keyword(s):  
Probability Theory ◽  
Crystal Plasticity ◽  
Voronoi Tessellation ◽  
Control Variable ◽  
Integrated System ◽  
Physical Parameters ◽  
Face Centered Cubic ◽  
Grain Structures ◽  
Face Centered ◽  
Fcc Materials

Based on Voronoi tessellation and the probability theory, a VGRAIN system is created for the generation of grains and grain boundaries for micromaterials. This system requires physical parameters obtained from microstructures of materials, such as the average, minimum and maximum grain sizes. Numerical procedures have been established to link the physical parameters of a material to the control variable in a gamma distribution equation and a method has been developed to solve the probability equation. These are the basis for the development of the VGRAIN system, which can be used to generate different grain structures and shapes that follow a certain pattern according to the probability theory. Statistical analyses have been carried out to investigate the distribution of generated virtual grains. The generated virtual microstructure is then implemented in the commercial FE code, ABAQUS, for mesh generation and micromechanics analysis using crystal plasticity (CP) equations for face-centered cubic (FCC) materials, which are implemented in the commercial FE solver, ABAQUS, through the user-defined subroutines, VUMAT/UMAT. FE analyses have been carried out to demonstrate the effectiveness of the integrated system for the investigation of localized straining and necking, encountered in microforming processes, such as extrusion of micropins, deformation of microfilms and hydroforming of microtubes.

An Integrated Approach for Virtual Microstructure Generation and Micro-Mechanics Modelling for Micro-Forming Simulation

2007 ◽  
Author(s):  
Kar Cheong Ho ◽  
Nan Zhang ◽  
Jianguo Lin ◽  
Trevor Anthony Dean
Keyword(s):  
Probability Theory ◽  
Crystal Plasticity ◽  
Voronoi Tessellation ◽  
Control Variable ◽  
Integrated Approach ◽  
Physical Parameters ◽  
Micro Forming ◽  
Forming Simulation ◽  
Grain Structures ◽  
Fcc Materials

To aid FE simulation for forming micro-components, an integrated approach is proposed to generate virtual microstructure for micro-mechanics modelling. Based on Voronoi tessellation and the probability theory, a VGRAIN system is created for the generation of grains and grain boundaries for micro-materials. The input data of the system are physical parameters of a material, including average, minimum and maximum grain sizes. Numerical procedures have been established to link the physical parameters of a material to the control variable in a gamma distribution equation and a method has been developed to solve the probability equation. These are the basis for the development of the VGRAIN system, which can be used to generate different grain structures and shapes that follow a certain pattern according to the probability theory. Statistical analyses have been carried out to investigate the distribution of generated virtual grains. The generated virtual microstructure is then implemented in the commercial FE code, ABAQUS, for mesh generation and micro-mechanics analysis using crystal plasticity equations for FCC materials. The crystal plasticity model is implemented in the commercial FE code, ABAQUS, through the used-defined subroutine, UMAT. FE analyses have been carried out to investigate size effects and localised necking encountered in micro-forming processes.

AN INTEGRATED MICROMECHANICS MODELLING APPROACH FOR MICRO-FORMING SIMULATION

2008 ◽  
Vol 22 (31n32) ◽  
pp. 5907-5912 ◽  
Author(s):  
W. ZHUANG ◽  
J. LIN
Keyword(s):  
Voronoi Tessellation ◽  
Control Variable ◽  
Integrated System ◽  
Physical Parameters ◽  
Micro Forming ◽  
Forming Process ◽  
Forming Simulation ◽  
Localized Necking ◽  
Micro Parts ◽  
Microstructure Of The Material

An effort has been made to create an integrated Crystal Plasticity FE (CPFE) system. This enables micro-forming process simulation to be carried out easily and the important features in forming micro-parts can be captured. Firstly, based on Voronoi tessellation and the probability theory, a VGRAIN system is created for the generation of grains and grain boundaries for micro-materials. Numerical procedures have been established to link the physical parameters of a material to the control variable in a gamma distribution equation. An interface has been created, so that the generated virtual microstructure of the material can be inputted in the commercial FE code, ABAQUS, for mesh generation. Secondly, FE analyses have been carried out to demonstrate the effectiveness of the integrated system for the investigation of uncontrollable curvature and localized necking in extrusion of micro-pins and hydro-forming of micro-tubes.

scholarly journals The strain hardening of micro-sized face-centered-cubic single crystal metals: A crystal plasticity study

AIP Advances ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 125208 ◽  
Author(s):  
Huili Guo ◽  
Chenlin Li ◽  
Xu Zhang ◽  
Fulin Shang
Keyword(s):  
Single Crystal ◽  
Strain Hardening ◽  
Crystal Plasticity ◽  
Face Centered Cubic ◽  
Face Centered

scholarly journals A Micromechanical Model of Additively Manufactured Aluminum Alloys

2019 ◽  
Vol 221 ◽  
pp. 01016
Author(s):  
Evgeniya Emelianova ◽  
Varvara Romanova ◽  
Olga Zinovieva ◽  
Ruslan Balokhonov ◽  
Aleksandr Zinoviev ◽  
...  
Keyword(s):  
Aluminum Alloys ◽  
Plastic Anisotropy ◽  
Micromechanical Model ◽  
Three Dimensional ◽  
Face Centered Cubic ◽  
Melt Pool ◽  
Grain Structures ◽  
Face Centered ◽  
Three Dimensional Models ◽  
Packing Method

A micromechanical model is developed to predict the deformation behavior of additively manufactured aluminum alloys. Three-dimensional models of grain structures typical for different microregions of the melt pool are generated by the step-by-step packing method. A crystal plasticity-based constitutive model accounting for the elastic-plastic anisotropy of face-centered cubic crystals is employed to simulate the microscale deformation in an additively manufactured aluminum alloy under loading. The grain shape and texture effects on the plastic strain localization patterns are analyzed.

Bulk nanocrystalline stainless steel fabricated by equal channel angular pressing

2006 ◽  
Vol 21 (7) ◽  
pp. 1687-1692 ◽  
Author(s):  
C.X. Huang ◽  
Y.L. Gao ◽  
G. Yang ◽  
S.D. Wu ◽  
G.Y. Li ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Equal Channel Angular Pressing ◽  
Face Centered Cubic ◽  
Angular Pressing ◽  
Grain Structures ◽  
Strain Induced Martensite ◽  
High Resolution Tem ◽  
Cubic Structure ◽  
Face Centered ◽  
Bulk Nanocrystalline

Bulk fully nanocrystalline grain structures were successfully obtained in ultralow carbon stainless steel by means of equal channel angular pressing at room temperature. Transmission electron microscopy (TEM) and high-resolution TEM investigations indicated that two types of nanostructures were formed: nanocrystalline strain-induced martensite (body-centered cubic structure) with a mean grain size of 74 nm and nanocrystalline austenite (face-centered cubic structure) with a size of 31 nm characterized by dense deformation twins. The results about the formation of fully nanocrystalline grain structures in stainless steel suggested that a low stacking fault energy is exceptionally profitable for producing nanocrystalline materials by equal channel angular pressing.

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