The predictive capability of progressive damage and failure analysis (PDFA) methods for composite structures must be validated against experiment for effective maturation to be achieved. The lack of publically available experimental data has protracted the development of such methods and slowed forward progress in the field. As such, a high fidelity database of composite failure characterization tests using IM7/5320-1 was created through the Office of Naval Research (ONR) High Fidelity Database and Validation Protocols program to aid in verification and validation (V&V) of PDFA methods. As a next step, the ONR High Fidelity Building Block and Validation Protocols for NextGen Composite Methods program seeks to expand upon the high fidelity database and the V&V protocols developed in the previous program. This work presents a V&V approach developed for simulating off-axis tension (OAT) and compression (OAC) samples as demonstrated using the material modeling capabilities within MAT299 in LS-DYNA. The simulations are first verified with analytical solutions for stiffness and strength of the OAT and OAC models. Validation is then completed against experimental data obtained at room-temperature ambient (RTA), cold-temperature dry (CTD), and elevated-temperature wet (ETW) conditions. Limitations in the modeling method are discussed as well as applicability of the LaRC- 04 failure envelope to test data at different environmental conditions.

This paper presents an approach for using high fidelity test data to inform modeling methods on progressive damage failure analysis for composite open hole tension specimens at room temperature ambient and cold temperature dry conditions. To do this, the progressive damage failure models will use a publically available continuum damage mechanics based material model (MAT299) to represent lamina level damage in unidirectional composite systems within LS-DYNA. The models will be evaluated against a high fidelity experimental database from a project sponsored by the Office of Naval Research. The database consists of experimental data for the material system IM7/5320-1. Soft, medium, and hard laminates at each environmental condition will be the focus of this paper.

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Progressive Damage and Failure Analysis (PDFA) has been shown to effectively predict damage initiation and propagation of composite materials at the lamina length scale when subjected to various forms of structural loading. The MAT299 composite damage model was developed by Boeing and LST/ANSYS and implemented as a native capability within the LS-DYNA explicit FEA suite under the Impact Damage Analysis Tools for Composite Structures (IDAT) program through the Air Force Research Laboratory in 2020. The material model was thoroughly verified and validated for low velocity impact events under the IDAT program using high fidelity ply-by-ply models. This work addresses the scalability of the MAT299 material model by investigating the effectiveness of thick shell elements implemented in an equivalent single layer scheme for low velocity impact of composite structures. Demonstrating the predictive capability of MAT299 with the thick shell implementation is a significant step toward applying PDFA methods at structurally relevant length scales.