Thermal Property Determination Using Optimization of One-side Known Radiant Exposure

Structural applications, including aircraft, ships, and offshore oil drilling platforms, have witnessed a surge in composite material usage. However, exposure to elevated temperatures poses a significant risk to these materials, especially in scenarios such as fires and high-temperature exhaust gas impingement. Despite limited or no visible damage, composite properties can undergo significant degradation, leading to potential in-service failures and jeopardizing operational safety and integrity. It was previously determined that the accuracy of the equipment and methodology used for measuring elevated temperature thermal properties, particularly in predicting composite material thermal properties could not meet the necessary precision. Using an inverse analysis technique to solve for the thermal conductivity and specific heat capacity, the thermal properties of composite materials can be determined. These thermal properties can then be used in a rapid heat damage assessment and failure prediction tool that can be updated based on additional data provided during inspection which takes into account material state changes and damage development due to the elevated temperature exposure and provides a way to incorporate those changes into subsequent structural analyses.