TY - GEN
T1 - An abaqus implementation of the regularized extended finite element method with novel mixed mode cohesive fatigue model
AU - Liang, Yu Jui
AU - Adluru, Hari K.
AU - Iarve, Endel V.
N1 - Publisher Copyright:
© ASC 2020.
PY - 2020
Y1 - 2020
N2 - The Regularized eXtended Finite Element Method (Rx-FEM) is a fracture mechanics based technique for progressive failure simulation in which multiple damage events, such as matrix cracks and delaminations, are introduced into the finite element model via mesh-independent displacement discontinuities. In the Rx-FEM, the Heaviside step function used in the eXtended Finite Element Method (x-FEM) is replaced by a continuous function approximated by the FE shape functions. This regularization lends itself to a natural implementation in commercial finite element software as a superposition of native elements. The advantages of Rx-FEM implementation lie in its ability to utilize built-in capabilities from the host software, including contact, variety of native elements, geometric nonlinearity, as well as the standard post-processing, and visualization tools. This capability of Rx-FEM to insert mesh-independent cohesive interfaces also makes the method particularly well suited for the analysis of fatigue damage propagation in composites. A recently-developed cohesive fatigue model was implemented into the Rx-FEM framework for the Abaqus software suite. This fatigue model assumes that the cohesive law that describes quasi-static tearing is the envelope of the fatigue damage. Fatigue damage accumulates within the envelope at a rate that satisfies the S-N diagram and Miner’s rule. The parameters of the model are obtained from idealizations of S-N diagrams used in engineering design. The fatigue model relies on intrinsic relationships between S-N curves and their corresponding Paris law curves to predict the rates of crack propagation. The implementation of the new fatigue model is demonstrated by comparing the experimental and predicted response and failure of a mixed-mode bending (MMB) test, as well as a Clamped Tapered Beam (CTB) sub-element. The CTB is a test designed to study matrix crack and delamination initiation and subsequent propagation and migration from one ply interface to another.
AB - The Regularized eXtended Finite Element Method (Rx-FEM) is a fracture mechanics based technique for progressive failure simulation in which multiple damage events, such as matrix cracks and delaminations, are introduced into the finite element model via mesh-independent displacement discontinuities. In the Rx-FEM, the Heaviside step function used in the eXtended Finite Element Method (x-FEM) is replaced by a continuous function approximated by the FE shape functions. This regularization lends itself to a natural implementation in commercial finite element software as a superposition of native elements. The advantages of Rx-FEM implementation lie in its ability to utilize built-in capabilities from the host software, including contact, variety of native elements, geometric nonlinearity, as well as the standard post-processing, and visualization tools. This capability of Rx-FEM to insert mesh-independent cohesive interfaces also makes the method particularly well suited for the analysis of fatigue damage propagation in composites. A recently-developed cohesive fatigue model was implemented into the Rx-FEM framework for the Abaqus software suite. This fatigue model assumes that the cohesive law that describes quasi-static tearing is the envelope of the fatigue damage. Fatigue damage accumulates within the envelope at a rate that satisfies the S-N diagram and Miner’s rule. The parameters of the model are obtained from idealizations of S-N diagrams used in engineering design. The fatigue model relies on intrinsic relationships between S-N curves and their corresponding Paris law curves to predict the rates of crack propagation. The implementation of the new fatigue model is demonstrated by comparing the experimental and predicted response and failure of a mixed-mode bending (MMB) test, as well as a Clamped Tapered Beam (CTB) sub-element. The CTB is a test designed to study matrix crack and delamination initiation and subsequent propagation and migration from one ply interface to another.
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M3 - Conference contribution
AN - SCOPUS:85097287984
T3 - Proceedings of the American Society for Composites - 35th Technical Conference, ASC 2020
SP - 1510
EP - 1526
BT - Proceedings of the American Society for Composites - 35th Technical Conference, ASC 2020
A2 - Pochiraju, Kishore
A2 - Gupta, Nikhil
PB - DEStech Publications
T2 - 35th Annual American Society for Composites Technical Conference, ASC 2020
Y2 - 14 September 2020 through 17 September 2020
ER -