Investigation on the failure behavior and compressive performance of rigid polyurethane foam treated under aerobic/anaerobic high temperature random vibration

Abstract

In this paper, the thermal vibration damage of rigid polyurethane foam (RPUF) under the action of oxygen, temperature and vibration was systematically studied by the combination of experiment and finite element analysis. The damage degree of RPUF was evaluated by their compressive mechanical properties and energy absorption properties. The results of Fourier infrared spectrum (FTIR) and nuclear magnetic resonance (13C NMR) showed that the thermal degradation of the carbamate group was the main chemical failure process of RPUF in the aerobic/anaerobic high temperature environment. Particularly, the thermal oxidative degradation of ether bonds occurred in an aerobic high temperature environment. It was also proved by the simulation results of Discrete Fourier Transform (DFT). Compression experiments showed that with the increase of temperature, the compressive mechanical properties and energy absorption properties of the RPUF gradually decrease until they reach the minimum value at 150 °C.These compressive performances of the thermal vibration group (treated in thermal vibration environment) were lower than the corresponding heat treatment group (treated in heat treatment environment). In the 50–300Hz, 550–800Hz and 1050–1300Hz, the failure degree of the low-frequency stage (50–300Hz) is also the highest among the thermal vibration group. At this time, the elastic modulus and compression yield strength of the aerobic 150 °C thermal vibration group were 14.47 MPa and 1.17 MPa, respectively, which were 19.6% and 9.3% lower than the anaerobic 150 °C thermal vibration group.