TY - GEN
T1 - Coupling Continuum Damage Mechanics and Discrete Fracture Models
T2 - 16th International Conference of the International Association for Computer Methods and Advances in Geomechanics, IACMAG 2021
AU - Arson, Chloé F.
AU - Jin, Wencheng
AU - He, Haozhou
N1 - Publisher Copyright:
© 2021, The Author(s), under exclusive license to Springer Nature Switzerland AG.
PY - 2021
Y1 - 2021
N2 - We present numerical methods to simulate the propagation of discrete fractures embedded in a damaged zone. Continuum Damage Mechanics (CDM) models are implemented in a Finite Element (FE) analysis code. A damage threshold defines the beginning of micro-crack coalescence, when a discrete cohesive segment opens. First, Cohesive Zone (CZ) elements are inserted between volume elements. The length and orientation of the discrete fracture are controlled by the magnitude of the energy released at integration points. The fracture path highly depends on space discretization, but the damage threshold is calculated automatically upon CDM model calibration. Second, an eXtended Finite Element Method (XFEM) approach is proposed. The fracture path is a function of the weighted average direction of maximum damage. Fracture growth depends on a nonlocal internal length, and the damage threshold is set empirically. Both coupling methods perform satisfactorily for simulating pure mode I or pure mode II fracture propagation resulting from micro-crack coalescence. However, the derivation of the Jacobian matrix in the XFEM makes it impractical to couple CDM and CZ models when the damaged stiffness cannot be expressed explicitly. For mixed mode fracture propagation and bifurcation problems, CZ insertion shows great promise, but mesh dependency and computational cost remain challenging.
AB - We present numerical methods to simulate the propagation of discrete fractures embedded in a damaged zone. Continuum Damage Mechanics (CDM) models are implemented in a Finite Element (FE) analysis code. A damage threshold defines the beginning of micro-crack coalescence, when a discrete cohesive segment opens. First, Cohesive Zone (CZ) elements are inserted between volume elements. The length and orientation of the discrete fracture are controlled by the magnitude of the energy released at integration points. The fracture path highly depends on space discretization, but the damage threshold is calculated automatically upon CDM model calibration. Second, an eXtended Finite Element Method (XFEM) approach is proposed. The fracture path is a function of the weighted average direction of maximum damage. Fracture growth depends on a nonlocal internal length, and the damage threshold is set empirically. Both coupling methods perform satisfactorily for simulating pure mode I or pure mode II fracture propagation resulting from micro-crack coalescence. However, the derivation of the Jacobian matrix in the XFEM makes it impractical to couple CDM and CZ models when the damaged stiffness cannot be expressed explicitly. For mixed mode fracture propagation and bifurcation problems, CZ insertion shows great promise, but mesh dependency and computational cost remain challenging.
KW - Cohesive zone model
KW - Continuum damage mechanics
KW - Extended finite element method
KW - Finite element method
KW - Geomechanics
KW - Multiscale coupling
UR - https://www.scopus.com/pages/publications/85101566885
UR - https://www.mendeley.com/catalogue/7e6c6bbf-c87d-350d-be7e-7f83164146ab/
U2 - 10.1007/978-3-030-64514-4_1
DO - 10.1007/978-3-030-64514-4_1
M3 - Conference contribution
AN - SCOPUS:85101566885
SN - 9783030645137
T3 - Lecture Notes in Civil Engineering
SP - 3
EP - 18
BT - Challenges and Innovations in Geomechanics - Proceedings of the 16th International Conference of IACMAG - Volume 1
A2 - Barla, Marco
A2 - Di Donna, Alice
A2 - Sterpi, Donatella
PB - Springer Science and Business Media Deutschland GmbH
Y2 - 5 May 2021 through 8 May 2021
ER -