High Fidelity Heat Damage Simulation of Polymer Composite Structures

Naval aircraft in operation face the risk of over-temperature incidents such as fires and high-temperature exhaust gas impingement. Assessing the condition of composite aircraft structures after exposure from excessive heat is important since a thermally damaged component could fail and result in a catastrophic accident. Existing simulation tools are not able to provide reliable damage assessment of large-scale structures experiencing elevated temperature incidents.Ā There is a need to develop improved simulation tools that can rapidly assess thermally induced damage to maximize aircraft safety and reduce maintenance cost in support of the US NavyÆs mission. Luna Innovations Incorporated has teamed with Virginia Tech to develop a multi-physics simulation tool that can quickly assess residual structural integrity of polymer composite aircraft structures exposed to excessive heat.Ā Phase II work will further develop this tool, enabling the Navy to predict the residual mechanical properties of structural composites exposed to excessive heat with less than 6% error. To accurately predict mechanical property loss after heat exposure, models to describe the heat transfer within the composite will be fully defined and verified. The Luna-VT team will update material properties and kinetic parameters to improve prediction accuracy of the heat transfer model developed in Phase I. A decomposition kinetics model and mechanical degradation model will be defined and used to predict the residual strength of composite panels and aircraft components exposed to heat. The desired multi-physics model relating composite material heat exposure to residual strength will then be completed by implementing the derived heat transfer, decomposition kinetics and mechanical degradation models into ABAQUS (a commercial finite element solver).Ā Experiments on composite panels and aircraft sub-components will be performed to validate the ability of the model to predict the temperature profile throughout the composite structure and resulting mechanical degradation after exposure to excessive heat. After validation, the novel multi-physics based simulation tool will be delivered to the Navy for evaluation.