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This makes it possible to predict advanced composite structure/component safety using progressive failure analysis and virtual testing based on the physics and micro/macro mechanics of materials, manufacturing processes, available data, and service environments. The process uses a building block strategy for simulation and verification of aircraft and launch vehicle engine structures before critical design steps. This approach provides the only software tool in the world that takes progressive damage and fracture processes into account and accurately assesses reliability and durability by predicting failure initiation and progression based on constituent material properties. It enables meaningful risk management simulations and synthesis of next generation turbine blade structures. The life prediction codes (Figure 2 left ) utilize and integrate

1. finite element structural analysis such as nodal based (Mhost), Element bases (Ansys, NASTRAN_Sol 106, and ABAQUS).
2. micro-mechanics and fracture mechanics including fiber, interface, and matrix stress-strain that can includes the manufacturing anomalies such as fiber deviation/draping, manufacturing residual stress, etc.
3. damage progression tracking damage index formation in fiber and matrix, including the micro-crack density residual stiffness formation during service
4. probabilistic risk assessment, to evaluate the sensitivity of material constituents to failure (i.e. delamination).
5. minimum damage design optimization, suppressing the failure mechanisms considering the material, geometry
6. material characterization codes to scale up the effects of local damage mechanisms to the structure level to evaluate overall performance and integrity.

A significant advantage of using a life prediction tool over finite element analysis in the design process is that the number of experimental tests at the component and substructure levels can be substantially reduced and experimental testing that is done made more efficient and effective. The use of life prediction software for ceramic component design must include performing:

1. Material Characterization Analysis (MCA) [4],
2. Material Uncertainty Analysis (MUA)
3. Material Characterization Optimization,
4. Progressive Failure Analysis (PFA),
5. Probabilistic Progressive Failure Analysis (PPFA)-Time Dependent Reliability (TDR), and
6. Design optimization to achieve damage minimization under environmental loading conditions.

The GENOA code (Figure ) integrates: 1) finite element structural analysis with nonlinear stress-strain and plasticity considerations, 2) composite micro-mechanics, and fracture mechanics options, 3) damage progression tracking, 4) probabilistic risk assessment, 5) minimum damage design optimization, and 6) material characterization codes to scale up the effects of local damage mechanisms to the structure level to evaluate overall performance and integrity. The GENOA finite element structural analysis module performs automated re-meshing to zoom in on critical points and track the initiation and growth of cracks of any size. Cracks as small as 0.01 inch long in F-18 composite aircraft structures have been successfully detected and tracked by GENOA in quantifying structural damage tolerance. A significant advantage of using VT in the design process is that the number of experimental tests at the component and substructure levels can be substantially reduced and experimental testing that is done made more efficient and effective.

Generalized Optimization and Analysis (GENOA) Software
Flow Chart, Finite Element (NASTRAN, ANSYS, MHOST)

GENOA Software Capability as a Life Prediction tools

Figure 2: Functionality of GENOA Software

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