### Abstract

A material model which incorporates several key capabilities which have been identified by the aerospace community as lacking in state-of-the art composite impact models is under development. In particular, a next generation composite impact material model, jointly developed by the FAA and NASA, is being implemented into the commercial transient dynamic finite element code LS-DYNA. The material model, which incorporates plasticity, damage, and failure, utilizes experimentally based tabulated input to define the evolution of plasticity and damage and the initiation of failure as opposed to specifying discrete input parameters (such as modulus and strength). The plasticity portion of the orthotropic, three-dimensional, macroscopic composite constitutive model is based on an extension of the Tsai-Wu composite failure model into a generalized yield function with a non-associative flow rule. For the damage model, a strain equivalent formulation is utilized to allow for the uncoupling of the deformation and damage analyses. In the damage model, a semicoupled approach is employed where the overall damage in a particular coordinate direction is assumed to be a multiplicative combination of the damage in that direction resulting from the applied loads in the various coordinate directions. Due to the fact that the plasticity and damage models are uncoupled, test procedures and methods to both characterize the damage model and to covert the material stress-strain curves from the true (damaged) stress space to the effective (undamaged) stress space have been developed. A methodology has been developed to input the experimentally determined composite failure surface in a tabulated manner. An analytical approach is then utilized to track how close the current stress state is to the failure surface.

Original language | English (US) |
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Title of host publication | Proceedings of the American Society for Composites - 31st Technical Conference, ASC 2016 |

Publisher | DEStech Publications Inc. |

ISBN (Electronic) | 9781605953168 |

State | Published - 2016 |

Event | 31st Annual Technical Conference of the American Society for Composites, ASC 2016 - Williamsburg, United States Duration: Sep 19 2016 → Sep 21 2016 |

### Other

Other | 31st Annual Technical Conference of the American Society for Composites, ASC 2016 |
---|---|

Country | United States |

City | Williamsburg |

Period | 9/19/16 → 9/21/16 |

### Fingerprint

### ASJC Scopus subject areas

- Ceramics and Composites

### Cite this

*Proceedings of the American Society for Composites - 31st Technical Conference, ASC 2016*DEStech Publications Inc..

**Analysis and characterization of damage and failure utilizing a generalized composite material model suitable for use in impact problems.** / Goldberg, R. K.; Carney, K. S.; Dubois, P.; Khaled, B.; Hoffarth, C.; Rajan, Subramaniam; Blankenhorn, G.

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

*Proceedings of the American Society for Composites - 31st Technical Conference, ASC 2016.*DEStech Publications Inc., 31st Annual Technical Conference of the American Society for Composites, ASC 2016, Williamsburg, United States, 9/19/16.

}

TY - GEN

T1 - Analysis and characterization of damage and failure utilizing a generalized composite material model suitable for use in impact problems

AU - Goldberg, R. K.

AU - Carney, K. S.

AU - Dubois, P.

AU - Khaled, B.

AU - Hoffarth, C.

AU - Rajan, Subramaniam

AU - Blankenhorn, G.

PY - 2016

Y1 - 2016

N2 - A material model which incorporates several key capabilities which have been identified by the aerospace community as lacking in state-of-the art composite impact models is under development. In particular, a next generation composite impact material model, jointly developed by the FAA and NASA, is being implemented into the commercial transient dynamic finite element code LS-DYNA. The material model, which incorporates plasticity, damage, and failure, utilizes experimentally based tabulated input to define the evolution of plasticity and damage and the initiation of failure as opposed to specifying discrete input parameters (such as modulus and strength). The plasticity portion of the orthotropic, three-dimensional, macroscopic composite constitutive model is based on an extension of the Tsai-Wu composite failure model into a generalized yield function with a non-associative flow rule. For the damage model, a strain equivalent formulation is utilized to allow for the uncoupling of the deformation and damage analyses. In the damage model, a semicoupled approach is employed where the overall damage in a particular coordinate direction is assumed to be a multiplicative combination of the damage in that direction resulting from the applied loads in the various coordinate directions. Due to the fact that the plasticity and damage models are uncoupled, test procedures and methods to both characterize the damage model and to covert the material stress-strain curves from the true (damaged) stress space to the effective (undamaged) stress space have been developed. A methodology has been developed to input the experimentally determined composite failure surface in a tabulated manner. An analytical approach is then utilized to track how close the current stress state is to the failure surface.

AB - A material model which incorporates several key capabilities which have been identified by the aerospace community as lacking in state-of-the art composite impact models is under development. In particular, a next generation composite impact material model, jointly developed by the FAA and NASA, is being implemented into the commercial transient dynamic finite element code LS-DYNA. The material model, which incorporates plasticity, damage, and failure, utilizes experimentally based tabulated input to define the evolution of plasticity and damage and the initiation of failure as opposed to specifying discrete input parameters (such as modulus and strength). The plasticity portion of the orthotropic, three-dimensional, macroscopic composite constitutive model is based on an extension of the Tsai-Wu composite failure model into a generalized yield function with a non-associative flow rule. For the damage model, a strain equivalent formulation is utilized to allow for the uncoupling of the deformation and damage analyses. In the damage model, a semicoupled approach is employed where the overall damage in a particular coordinate direction is assumed to be a multiplicative combination of the damage in that direction resulting from the applied loads in the various coordinate directions. Due to the fact that the plasticity and damage models are uncoupled, test procedures and methods to both characterize the damage model and to covert the material stress-strain curves from the true (damaged) stress space to the effective (undamaged) stress space have been developed. A methodology has been developed to input the experimentally determined composite failure surface in a tabulated manner. An analytical approach is then utilized to track how close the current stress state is to the failure surface.

UR - http://www.scopus.com/inward/record.url?scp=85013964144&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85013964144&partnerID=8YFLogxK

M3 - Conference contribution

AN - SCOPUS:85013964144

BT - Proceedings of the American Society for Composites - 31st Technical Conference, ASC 2016

PB - DEStech Publications Inc.

ER -