The investigation of plastic behavior by discrete dislocation dynamics for single crystal pillar at submicron scale

• Main Author: Cui, Yinan (Author)
• Format: Electronic eBook
• Language: English
• Published: Singapore : Springer, 2016, ©2017.
• Series: Springer theses.
• Subjects: Dislocations in crystals.; Plasticity.; elektronické knihy; electronic books
• ISBN: 9789811030321; 9789811030314
• Physical Description: 1 online resource (141 pages)

Table of Contents:

• Supervisor's Foreword; Abstract; Parts of this thesis have been published in the following articles:Cui YN, Liu ZL, Zhuang Z. Theoretical and numerical investigations on confined plasticity in micropillars. Journal of the Mechanics and Physics of Solids, 2015, 76, 127-143 (Reproduced with Permission). Cui YN, Liu ZL, Wang ZJ, Zhuang Z. Mechanical annealing under low amplitude cyclic loading in micropillars. Journal of the Mechanics and Physics of Solids, 2016, 89, 1-15 (Reproduced with Permission). Cui YN, Lin P, Liu ZL, Zhuang Z; Acknowledgments; Contents; 1 Introduction.
• 1.1 Background and Significance1.1.1 Size Effect of Yield Stress; 1.1.2 Strain Burst and Dislocation Avalanches; 1.1.3 Size Effect of Cyclic Behavior; 1.2 Research Methods; 1.2.1 Non-local Crystal Plasticity; 1.2.2 Discrete Dislocation Dynamics Simulation Method; 1.3 Research Content; References; 2 Discrete-Continuous Model of Crystal Plasticity; 2.1 Introduction of Simulation Method; 2.1.1 Discrete Dislocation Dynamics (DDD); 2.1.1.1 Dislocation Kinetic Equation; 2.1.1.2 Dislocation Reaction and Topology Update; 2.1.1.3 Dislocation Cross Slip; 2.1.2 Coupling DDD with Finite Element Method.
• 2.1.2.1 Superposition Method (SPM)2.1.2.2 Discrete-Continuous Model (DCM); 2.2 Improved Discrete-Continuous Model; 2.2.1 Efficient Regularization Method; 2.2.1.1 Review of Different Regularization Methods; 2.2.1.2 Novel Regularization Method; 2.2.1.3 Stress Field Calculation of Prismatic Loop; 2.2.2 Image Force Calculation; 2.2.2.1 Stress Interpolation; 2.2.2.2 Hybrid DCM Method; 2.2.3 Finite Deformation; 2.2.3.1 Deformation Field Transfer and Surface Dislocation Treatment; 2.2.3.2 Slip System Rotation; 2.2.3.3 Reproduction of Slip Step; 2.2.4 Application in Heteroepitaxial Film.
• 2.2.4.1 Thermoelastic Calculation to Determine Internal Stress Field2.2.4.2 Influence of Substrate Thickness on Dislocation Behavior; 2.3 Summary; References; 3 Single Arm Dislocation Source Controlled Plastic Flow in FCC Micropillars; 3.1 Simulation Setup; 3.2 Simulation Results; 3.2.1 SAS Controlled Strain Burst; 3.2.2 The Absence of Strain Hardening; 3.2.3 SAS Controlled Dislocation Density Evolution; 3.3 Theoretical Analysis; 3.3.1 Dislocation Density Evolution Model; 3.3.2 Predicting the Flow Stress; 3.4 Implications for Strain Hardening at Small Scales; 3.5 Summary; References.
• 4 Confined Plasticity in Micropillars4.1 Simulation Setup; 4.2 Results and Discussion; 4.2.1 Stress-Strain Curves in Coated and Uncoated Pillars; 4.2.2 Dislocation Source Mechanism in Coated Micropillar; 4.2.3 Back Stress in Coated Micropillar; 4.2.4 The Evolution of Mobile and Trapped Dislocation; 4.3 Implications on Crystal Plasticity Model; 4.4 Theoretical Model to Predict Stress-Strain Curve; 4.4.1 Description of the Theoretical Mode; 4.4.2 Prediction of Stress-Strain Curve; 4.5 Preliminary Analysis of Coating Failure Mechanism; 4.5.1 High Hoop Stress of the Coated Layer.