Preface |
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xiii | |
Nomenclature |
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xix | |
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1 | (18) |
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1.1 Partition of unity methods |
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1 | (5) |
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1.2 Moving boundary problems |
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6 | (2) |
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8 | (2) |
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10 | (5) |
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1.4.1 Implicit interface and signed distance functions |
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11 | (1) |
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1.4.2 Discretization of the level set |
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12 | (1) |
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1.4.3 Capturing motion interface |
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12 | (2) |
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1.4.4 Level sets for 3D fracture modeling |
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14 | (1) |
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15 | (4) |
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2 Weak forms and governing equations |
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19 | (10) |
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2.1 Strong form for pure mechanical problems |
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19 | (5) |
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2.1.1 One dimensional model problem |
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19 | (1) |
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2.1.2 Model problem in higher dimensions |
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20 | (1) |
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2.1.3 Total Lagrangian formulation |
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21 | (1) |
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2.1.4 Updated Lagrangian formulation |
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22 | (2) |
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2.2 From the strong form to the weak form |
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24 | (3) |
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2.2.1 Weak form for the one-dimensional model problem |
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24 | (2) |
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2.2.2 Weak form for the total Lagrangian formulation |
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26 | (1) |
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2.3 Variational formulation |
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27 | (2) |
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3 Extended finite element method |
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29 | (124) |
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3.1 Formulation and concepts |
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29 | (7) |
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29 | (5) |
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34 | (2) |
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3.2 Blending, integration and solvers |
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36 | (14) |
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36 | (4) |
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3.2.2 Isoparametric 2D quadrilateral XFEM element for linear elasticity |
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40 | (1) |
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41 | (1) |
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42 | (2) |
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3.2.5 The element stiffness matrix |
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44 | (2) |
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46 | (4) |
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3.3 XFEM for static/quasi-static fracture modeling in 2D and 3D |
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50 | (10) |
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3.3.1 XFEM approximation for cracks |
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50 | (4) |
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54 | (3) |
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3.3.3 Crack branching and crack junction |
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57 | (2) |
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3.3.4 Crack opening and crack closure |
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59 | (1) |
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3.4 XFEM for dynamic fracture modeling in 2D and 3D |
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60 | (5) |
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3.4.1 Diagonalized mass matrix |
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60 | (4) |
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64 | (1) |
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3.5 Smoothed extended finite element method |
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65 | (12) |
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3.5.1 Introduction to SFEM |
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67 | (3) |
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3.5.2 Enrichment in SXFEM and selection of enriched nodes |
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70 | (2) |
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3.5.3 Displacement-, strain field approximation and discrete equations |
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72 | (3) |
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3.5.4 Numerical integration |
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75 | (2) |
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3.6 XFEM for coupled problems |
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77 | (28) |
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3.6.1 Hydro-mechanical problems |
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77 | (12) |
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3.6.2 Thermo-mechanical problems |
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89 | (3) |
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3.6.3 Piezoelectric materials |
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92 | (8) |
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100 | (5) |
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3.7 XFEM for inverse analysis and topology optimization |
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105 | (41) |
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105 | (10) |
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3.7.2 Optimization problems |
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115 | (1) |
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3.7.3 Mathematical form of a structural optimization problem |
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116 | (1) |
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3.7.4 Solid isotropic material with penalization (SIMP) |
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117 | (1) |
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3.7.5 Level set based optimization |
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118 | (1) |
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118 | (12) |
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3.7.7 Nanopiezoelectricity |
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130 | (16) |
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3.8 Conditioning and solution of ill-conditioned systems |
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146 | (1) |
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147 | (6) |
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153 | (8) |
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4.1 Formulation and concepts |
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153 | (1) |
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4.2 A crack tip element for the phantom node methods |
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154 | (4) |
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4.2.1 Three-node triangular element |
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154 | (3) |
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4.2.2 Four-node quadrilateral element |
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157 | (1) |
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4.3 Multiple crack modeling |
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158 | (1) |
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159 | (2) |
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5 Extended meshfree methods |
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161 | (154) |
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5.1 Introduction to meshfree methods |
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161 | (10) |
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5.1.1 Basic approximation |
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161 | (1) |
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5.1.2 Completeness and conservation |
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162 | (2) |
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5.1.3 Consistency, stability and convergence |
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164 | (1) |
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165 | (1) |
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165 | (2) |
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167 | (4) |
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5.2 Some specific methods |
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171 | (19) |
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5.2.1 Approximation of the displacement field |
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171 | (6) |
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5.2.2 Spatial integration |
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177 | (8) |
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5.2.3 Essential boundary conditions |
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185 | (1) |
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5.2.4 Comparison of different methods |
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186 | (4) |
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5.3 Numerical instabilities |
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190 | (19) |
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5.3.1 Instability due to rank deficiency |
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192 | (1) |
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5.3.2 Tensile instability |
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193 | (1) |
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5.3.3 Attempts to remove instabilities |
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193 | (1) |
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5.3.4 Material instability in meshfree methods |
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194 | (15) |
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5.4 Fracture modeling in meshfree methods |
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209 | (8) |
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5.4.1 The visibility method |
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209 | (3) |
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5.4.2 The diffraction method |
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212 | (3) |
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5.4.3 The transparency method |
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215 | (2) |
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5.4.4 The "see through" and "continuous line" method |
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217 | (1) |
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5.5 The concept of enrichment |
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217 | (8) |
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5.5.1 Intrinsic enrichment |
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219 | (3) |
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5.5.2 Extrinsic enrichment |
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222 | (3) |
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5.6 (Extrinsically) enriched local PU meshfree methods |
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225 | (13) |
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5.6.1 Enriched methods with crack tip enrichment |
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226 | (4) |
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5.6.2 Enriched methods without crack tip enrichment |
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230 | (6) |
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5.6.3 Crack branching and crackjunction |
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236 | (2) |
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5.7 Extended local maximum entropy (XLME) |
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238 | (7) |
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5.7.1 Local Maximum Entropy (LME) approximants |
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239 | (4) |
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5.7.2 Numerical integration |
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243 | (2) |
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245 | (1) |
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5.8 Cracking particle methods |
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245 | (8) |
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5.8.1 The enriched cracking particles method |
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246 | (4) |
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5.8.2 Applications to large deformations |
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250 | (1) |
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5.8.3 The cracking particles method without enrichment |
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250 | (1) |
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5.8.4 Cracking rules for cracking particle methods |
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251 | (2) |
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5.9 Comparison of different methods |
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253 | (10) |
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5.9.1 The mode I crack problem |
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253 | (7) |
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5.9.2 The mixed mode problem |
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260 | (3) |
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5.10 Extensions to mode II kinematics |
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263 | (2) |
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5.10.1 Enriching in the shear band plane |
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263 | (2) |
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5.10.2 Enforcing mode II-kinematics with the penalty method |
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265 | (1) |
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5.11 Discrete system of equations for pure mechanical problems |
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265 | (18) |
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5.11.1 Methods without enrichment |
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265 | (2) |
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267 | (3) |
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5.11.3 Extension to dynamics |
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270 | (13) |
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283 | (3) |
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286 | (20) |
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5.13.1 Explicit-implicit time integration |
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286 | (1) |
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5.13.2 Explicit time integration, critical time step and mass lumping |
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287 | (17) |
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5.13.3 Crack propagation in time |
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304 | (2) |
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306 | (9) |
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6 Extended isogeometric analysis |
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315 | (44) |
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6.1 Formulation and concepts |
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315 | (5) |
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6.1.1 B-splines and NURBS |
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315 | (2) |
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317 | (3) |
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6.2 Hierarchical refinement with PHT-splines |
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320 | (4) |
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321 | (2) |
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6.2.2 Computing the control points |
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323 | (1) |
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6.3 Analysis using splines |
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324 | (5) |
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325 | (2) |
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327 | (2) |
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329 | (4) |
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6.4.1 Infinite plate with circular hole |
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329 | (1) |
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330 | (1) |
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331 | (1) |
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332 | (1) |
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333 | (8) |
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6.5.1 Determining the superconvergent point locations |
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333 | (4) |
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6.5.2 Superconvergent patch recovery |
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337 | (3) |
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340 | (1) |
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6.6 Multi-patch formulations for complex geometry |
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341 | (1) |
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6.7 XIGA for interface problems |
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341 | (14) |
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6.7.1 Governing and weak form equations |
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342 | (3) |
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6.7.2 Enriched basis functions selection |
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345 | (2) |
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6.7.3 Enrichment functions |
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347 | (1) |
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348 | (1) |
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6.7.5 Repeating middle neighbor knots |
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349 | (1) |
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350 | (1) |
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351 | (2) |
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6.7.8 Intersection points |
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353 | (1) |
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6.7.9 Triangular integration |
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354 | (1) |
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355 | (4) |
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7 Fracture in plates and shells |
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359 | (78) |
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7.1 Fractures in shell and plates using XFEM |
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359 | (11) |
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359 | (2) |
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7.1.2 Implementation based on the Q4 element |
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361 | (1) |
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362 | (1) |
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7.1.4 Curvature strain smoothing |
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363 | (2) |
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7.1.5 Extended finite element method for shear deformable plates |
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365 | (2) |
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7.1.6 Smoothed extended finite element method |
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367 | (1) |
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368 | (2) |
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7.2 Fractures in shell and plates using the phantom node method |
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370 | (22) |
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7.2.1 Phantom node method for the Belytschko-Tsay shell element |
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370 | (8) |
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7.2.2 Phantom node method based on the three-node isotropic triangular MITC shell element |
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378 | (14) |
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7.3 Extended meshfree methods for fracture in shells |
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392 | (10) |
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393 | (3) |
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7.3.2 Continuum constitutive models |
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396 | (1) |
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397 | (5) |
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7.4 An immersed particle method for fluid-structure interaction |
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402 | (6) |
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7.5 XIGA models for plates and shells |
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408 | (24) |
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7.5.1 Kinematics of the shell |
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408 | (2) |
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410 | (2) |
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7.5.3 Discretization of the displacement field and enrichment |
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412 | (7) |
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7.5.4 Discrete system of equations |
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419 | (3) |
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7.5.5 Edge cracked plates under tension or shear |
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422 | (6) |
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7.5.6 Pressurized cylinder with an axial crack |
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428 | (4) |
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432 | (5) |
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8 Fracture criteria and crack tracking procedures |
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437 | (34) |
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437 | (1) |
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437 | (8) |
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437 | (3) |
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8.2.2 Global energy criteria |
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440 | (1) |
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440 | (1) |
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8.2.4 Loss of material stability condition |
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441 | (2) |
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8.2.5 Rank-one-stability criterion |
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443 | (1) |
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8.2.6 Determining the crack orientation |
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444 | (1) |
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8.2.7 Computation of the crack length |
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444 | (1) |
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8.3 Crack surface representation and tracking the crack path |
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445 | (21) |
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8.3.1 The level set method to trace the crack path |
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447 | (4) |
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8.3.2 Tracking the crack path in 3D |
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451 | (11) |
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8.3.3 Adaptive crack propagation technique |
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462 | (2) |
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464 | (2) |
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466 | (5) |
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9 Multiscale methods for fracture |
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471 | (50) |
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9.1 Extended Bridging Domain Method |
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472 | (7) |
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9.1.1 Concurrent coupling of two models at different length scales |
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474 | (5) |
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9.1.2 Consistency of material properties |
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479 | (1) |
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9.2 Extended bridging scale method |
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479 | (12) |
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9.2.1 Consistency of material properties |
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481 | (2) |
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9.2.2 Upscaling and downscaling |
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483 | (8) |
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9.3 Multiscale aggregating discontinuity (MAD) method |
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491 | (12) |
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9.3.1 Overview of the method |
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491 | (3) |
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9.3.2 Coarse graining method |
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494 | (6) |
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9.3.3 Micro-macro linkage |
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500 | (3) |
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9.4 Crack opening in unit cells with the hourglass mode |
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503 | (1) |
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9.5 Stability of the macromaterial |
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504 | (3) |
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507 | (1) |
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508 | (8) |
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9.7.1 3D modeling of cracks in a nanocomposite |
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508 | (1) |
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9.7.2 Hierarchical multiscale example |
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508 | (2) |
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9.7.3 Semi-concurrent FE-FE coupling example |
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510 | (2) |
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9.7.4 Concurrent FE-XFEM coupling example |
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512 | (1) |
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9.7.5 MD-XFEM coupling example |
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513 | (3) |
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516 | (5) |
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10 A short overview of alternatives for fracture |
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521 | (60) |
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10.1 Numerical manifold method (finite cover method) |
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521 | (7) |
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10.1.1 The cover approximation |
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522 | (1) |
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10.1.2 The least square-based physical cover functions |
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523 | (1) |
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10.1.3 The imposition of boundary conditions |
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524 | (1) |
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524 | (3) |
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10.1.5 Geometric and material nonlinear analysis |
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527 | (1) |
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10.2 Peridynamics and dual-horizon peridynamics |
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528 | (34) |
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10.2.1 Dual-horizon peridynamics |
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531 | (8) |
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10.2.2 The dual property of dual-horizon |
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539 | (4) |
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10.2.3 Wave propagation in 1D homogeneous bar |
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543 | (1) |
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10.2.4 Numerical examples |
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544 | (18) |
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562 | (13) |
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563 | (5) |
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10.3.2 Governing equations |
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568 | (1) |
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569 | (3) |
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572 | (1) |
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573 | (2) |
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575 | (6) |
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11 Implementation details |
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581 | (20) |
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11.1 Computer implementation of enriched methods |
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581 | (9) |
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582 | (3) |
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585 | (4) |
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589 | (1) |
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590 | (7) |
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11.2.1 Crack propagation angle |
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591 | (1) |
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11.2.2 Hydro-mechanical model with center cracks |
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591 | (1) |
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11.2.3 Hydro-mechanical model with edge crack |
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592 | (5) |
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597 | (4) |
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A Derivation of shape derivative for the nanoelasticity problem |
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601 | (2) |
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B Derivation of the adjoint problem for the nanopiezoelectricity problem |
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603 | (4) |
Index |
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607 | |