Continuous Dislocation Dynamics Made Simple

• Record Nr.: UNINA9911009162603321
• Autore: Ngan Alfonso
• Pubbl/distr/stampa: Bristol : , : Institute of Physics Publishing, , 2024; ©2024
• ISBN: 9780750363327; 9780750363310
• Edizione: [1st ed.]
• Descrizione fisica: 1 online resource (155 pages)
• Collana: IOP Ebooks Series
• Altri autori (Persone): KalaeiAlireza
• Soggetti: Dislocations in crystals; Materials science
• Lingua di pubblicazione: Inglese
• Formato: Materiale a stampa
• Livello bibliografico: Monografia
• Nota di contenuto: Intro -- Foreword -- Author biographies -- Alfonso Ngan -- Alireza Kalaei -- Chapter Introduction -- 1.1 Slip system and dislocations -- 1.2 Multiscale modeling of crystal plasticity and the meso-scale gap -- 1.3 CDD and why this book? -- References -- Chapter What are dislocation densities? -- 2.1 Defects and their densities -- 2.2 Fine grained dislocation density -- 2.2.1 Bundle of parallel dislocations -- 2.2.2 Sub-dislocation density-intensive dislocation microstructures -- 2.3 Coarse grained dislocation density-extensive dislocation microstructures -- 2.3.1 Geometrically necessary dislocations (GNDs) and statistically stored dislocations (SSDs) -- 2.3.2 All-dislocation density (ADD) -- 2.4 The three distinctive length scales for dislocation plasticity -- References -- Chapter Kinematics of intensive line density: evolution laws and simulation codes -- 3.1 Maxwell's kinematics law for line density -- 3.2 Other forms of Maxwell's kinematics law -- 3.2.1 Movement-tilting form -- 3.2.2 Divergence-curvature form -- 3.2.3 Finite-difference form -- 3.3 Finite-difference numerical scheme -- 3.4 Simple MATLAB codes for line-density kinematics -- 3.4.1 Setting up line and coarse-graining into density -- 3.4.2 A basic MATLAB programme for expanding circle -- 3.4.3 Further considerations for solving line-density kinematics -- References -- Chapter Dynamics of intensive line density -- 4.1 Dynamics closure by ; velocity law -- 4.2 Mura's formula for long-range elastic interaction -- 4.2.1 Mura's formula for strain field of a dislocation loop -- 4.2.2 Mura's formula for continuous distribution of dislocations -- 4.3 Interaction within dislocation core -- 4.4 Simulation codes for internal interaction stress τint -- 4.4.1 Mura's elastic interaction -- 4.4.2 Applying long-range elastic and core interactions -- 4.4.3 Shrinkage of loop under self stress.; 4.5 Simulation of Orowan looping -- 4.5.1 Dislocation-particle interaction force law -- 4.5.2 Annihilation -- 4.5.3 Pinch-off -- 4.5.4 Simulation results -- 4.6 Simulation of Frank-Read source -- References -- Chapter All-dislocation density (ADD) for extensive microstructures-kinematics and dynamics closure -- 5.1 Extensive microstructures and ADD revisited -- 5.2 ADD and kinematics law of individual dislocations -- 5.3 Kinematics law of ADD for extensive microstructures comprising many dislocations -- 5.4 Alternative proofs of equation (5.12) -- 5.4.1 Using Maxwell's law for parallel dislocation bundles -- 5.4.2 Using Hochrainer's CDD -- 5.5 Multiple slip and dynamics closure -- 5.6 Elastoplastic framework for dynamics closure -- 5.6.1 Basics of elastoplastic framework -- 5.6.2 Plastic velocity gradient and Schmid tensor -- 5.6.3 Overall and internal deformations in dislocation-based crystal plasticity -- 5.6.4 Numerical implementation -- References -- Chapter Numerical scheme for ADD simulation -- 6.1 Realistic ADD for connected-line microstructures -- 6.2 Codes for ADD kinematics simulation -- 6.2.1 Codes for setting up initial ADD -- 6.2.2 Codes for ADD kinematics -- 6.3 Codes for dynamics simulation for ADD -- 6.3.1 MATLAB data structure for multiple slip systems -- 6.3.2 Code for setting up the initial ADD -- 6.3.3 Codes for Taylor interactions -- 6.3.4 Codes for Mura interactions -- 6.3.5 Codes for dynamics simulation of 3D multi-slip -- References -- Chapter Concluding remarks -- 7.1 Earlier CDD models revisited -- 7.1.1 Exact CDD for intensive dislocations as GNDs -- 7.1.2 Phenomenological CDD for GNDs + SSDs -- 7.2 The 'Beauty and the Beast' of CDD based on ADD -- 7.2.1 The 'Beauty': kinematics laws -- 7.2.2 The 'Beast': dynamics closure -- 7.3 What requires future work? -- References -- Chapter -- A.1 Tensors in solid mechanics.; A.1.1 Tensor order and rank -- A.1.2 Tensors as transformations between tensors -- A.1.3 Tensors from dyadic multiplication -- A.1.4 Tensor products -- A.2 Calculus of scalar, vector and tensor fields.
• Sommario/riassunto: This book introduces an exact approach to continuous dislocation dynamics based on the "all-dislocation" density (ADD), for mesoscopic simulation of coarse-grained dislocation microstructures.