Novel Multi-Physics Based Simulation Tool for Rapid Heat Damage Assessment of Polymer Composite Aircraft Structures Resulting from Excessive Heat Exposure

Navy SBIR 20.2 - Topic N202-094

Naval Air Systems Command (NAVAIR) - Ms. Donna Attick [email protected]

Opens: June 3, 2020 - Closes: July 2, 2020 (12:00 pm ET)

 

 

N202-094       TITLE: Novel Multi-Physics Based Simulation Tool for Rapid Heat Damage Assessment of Polymer Composite Aircraft Structures Resulting from Excessive Heat Exposure

 

RT&L FOCUS AREA(S): General Warfighting Requirements (GWR)

TECHNOLOGY AREA(S): Air Platform, Materials

 

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with section 3.5 of the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws.

 

OBJECTIVE: Develop a multi-physics simulation tool able to quickly assess residual structural integrity of thermoset polymer composite aircraft structures subjected to excessive heat.

 

DESCRIPTION: Naval aircraft in operation face the risk of over-temperature incidents. These include, but are not limited to, fires and high-temperature exhaust gas impingement. Protection of composite aircraft structures from excessive heat is important since thermally damaged composites are vulnerable to compressive failure. While char or discoloration evidence caused by fire or an overheating event may be visible from inspection of structure surfaces, internal thermal damage underneath the fire protection layer or thermal degradation due to long exposures above the designed to continuous operating temperature cannot be detected or structurally assessed by visual inspection alone. Replacement of suspect components is expensive, reduces aircraft availability, and is a known readiness degrader. Continued operation of a thermally damaged composite structure could result in a catastrophic failure. Without knowing the criticality or distribution of the thermally induced degradation, a repair solution cannot be implemented to restore the damaged component to the required load bearing capacity. Existing simulation tools cannot provide a quick solution for the damage assessment of a large-scale structure experiencing an over-temperature incident.

 

The Navy seeks development of a rapid-heat damage assessment and failure prediction tool to fill the current technology gap and support its mission driven operation. A high-fidelity solution process must be established to generate a rapid prediction tool that can be updated from additional data collected from inspection. Development of a multi-physics model capable of conservative prediction of the structural response for a given temporal and spatial evolution of thermal environment is desired. The thermal analysis of a composite structure exposed to excessive heat is complex because the heat transfer is controlled by many temperature- and rate-dependent processes such as thermal expansion and contraction, pressure rise, chemical decomposition, formation of matrix cracks, voids and delamination. The proposed approach should take into account the following phenomena: heat transfer, phase evolution and property degradation at micro-macro scale, damage progression under thermal-mechanical loading, multiple failure modes interaction, and multi-component structure failure.�

 

A comprehensive multi-physics model shall account for thermo-mechanical and thermo-chemical effects. The model must have the ability to calculate the temperature distribution within the composite when exposed to excessive heat. The model should take into account the effects of heat conduction, thermoset matrix pyrolysis, oxidation of carbon fibers, thermal expansion and diffusion of decomposition gases on the temperature distribution in the system. The model should be able to predict the composite decomposition kinetics as well as the degraded composite structural response. This model should also take into account the composite interaction with the associated high-temperature environment. The model should also include damage and failure prediction modules. The damage prediction module should allow the developed model to predict the type of damage depending on the temperature and exposure time, while the failure prediction module should estimate the failure behavior with respect to the over-temperature event characteristics. The inclusion of these two modules should allow the model the capacity to predict the overall behavior of composite structures when exposed to excessive heat.

 

PHASE I: Design and develop an accurate tool for the modeling of the transfer of heat through a composite exposed to excessive heat in residual strength analysis that includes the analysis of composition decomposition and damage. The accuracy of the model is dependent on the input data, and thermal experiments should be carried out during this phase. A proof of concept demonstration should be performed indicating the ability of the model in establishing a mapping relation between temperature and response of a loaded structural component. The Phase I effort will include prototype plans to be developed under Phase II.

 

PHASE II: Further develop and validate the model developed during Phase I through component/sub-scale testing. After validation, the model should be extended to multi-component laminated structures and sandwich composite structures. Transition feasibility should also be demonstrated during this phase. Acceptable error between predicted versus experiment can be no more than 2-6%.

 

PHASE III DUAL USE APPLICATIONS: Finalize and perform necessary testing to verify and validate. Transition to end users and commercial industries. Successful technology development would benefit the commercial aerospace industry.

 

REFERENCES:

1. Tranchard, P., Samyn, F., Duquesne, S., Estebe, B. and Bourbigot, S. �Modelling Behaviour of a Carbon Epoxy Composite Exposed to Fire: Part I�Characterization of Thermophysical Properties.� Materials, Vol 10, doi: 10.3390/ma10050494, 2017

 

2. Tranchard, P., Samyn, F., Duquesne, S., Estebe, B., and Bourbigot, S., �Modelling Behaviour of a Carbon Epoxy Composite Exposed to Fire: Part II�Comparison with Experimental Results,� Materials, Vol 10, doi: 10.3390/ma10050470, 2017

 

3. Quintiere, J.G., Walters, R. N. and Crowley, S. �Flammability properties of aircraft carbon-fiber structural composite.� DOT/FAA/AR-07/57, 2007. https://www.fire.tc.faa.gov/pdf/07-57.pdf

 

4. Nelson, James B. �Determination of Kinetic Parameters of Six Ablation Polymers by Thermogravimetric Analysis.� NASA TN D-3919, 1967. https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19670013969.pdf

 

KEYWORDS: Composite Fire, Thermal Analysis, Thermo-Mechanical Model And Thermo-Chemical Model, Property Degradation, Post-Fire Damage Assessment, Failure Modes Interaction, Decomposition Kinetics