The global thermal model has been developed and validated by UC3M for fire tests with thermoplastic materials.
The following tasks have been carried out during this reporting period:
WP1 - Design, development and installation of an innovative ground test environment:
SENSIA developed a solution based on infrared thermal imaging technology for monitoring the thermal map of the specimens under thermal/fire test.
WP2 - Test Campaigns and Specimens manufacturing:
All the specimens necessary for the mechanical and fire tests have been manufactured. Tests in a wide temperature range from room temperature, 200ºC and 300ºC have been performed including pull out and bearing tests. Two fire test panels have been instrumented with fiber optic sensors to measure the temperature in the middle of the panel to validate the theoretical model.
UC3M has participated in the thermal characterization of the panels. UC3M, as well, has verified the homogeneity and repeatability of the thermal properties of the specimens. In addition, UC3M has compared the thermal properties of thermoplastic specimens fabricated by INTA with those fabricated by external companies (FIDAMC) in order to verify the achievement of standard fabrication.
WP3 - Analysis and correlation:
UC3M has completed the mathematical model to simulate fire tests on thermoplastic materials. Two validation tests of the thermal model have been carried out for which an error less than 5% has been measured. Also, a comparison has been made on the behavior, under fire and load application, of thermoplastic to thermosetting specimens, the last had been studied prior to HITCOMP project by UC3M.
The development of the thermo-mechanical simulation model based on the FEM tool MSC Marc has been completed by INTA. The material mechanical constitutive model was developed by correlating coupon tests and fire tests results of panels under load. The model include the thermoplastic panel and the mechanical fitting for load introduction. Different fitting designs have been simulated, finishing finally with the realistic aeronautic fitting.
Overview of the results and their exploitation and dissemination:
- A complete thermal model (TM) for virtualizing tests of thermoplastic plane specimens when submitted under fire and mechanical load has been developed. TM has been validated for Toray CETEX TC1225.
- The model is enough robust to extend it to other different composite materials.
- TM should also be extended to virtualize other types of tests of similar characteristics, even for other types of metallic fittings or mechanical loads (pullout).
- In the fire and load tests carried out on thermoplastic (TP) and thermosetting (TS) specimens, the general conclusion regarding the resistance of both materials is that, for tests with similar characteristics (load, fire, thickness of material), the time to rupture is similar for both materials.
The Thermo-mechanical-TMM model has been compared, for validation, with a fire test measuring the time-to-rupture after applying fire and mechanical load. The error in the breaking time has been 22% in excess. The expected rupture time was 135 s, 30 seconds higher than the 105 s measured in the laboratory. This result can be considered quite good since it was the first one. Further research in this line should improve the simulation results.
