Study of failure behaviors of rigid polyurethane foam treated under thermal and vibration conditions by experiment and numerical simulation

Failure mechanism of rigid polyurethane foam (RPUF) treated under different conditions was studied by means of experiments and numerical simulation. Thermal degradation mechanism of RPUF under different temperatures was characterized by thermogravimetric analysis-Fourier transform infrared spectrometry coupled with gas chromatography–mass spectrometry (TG-FTIR-GC–MS) in air and nitrogen atmosphere, respectively. And the vibration failure mechanism of RPUF was analyzed by finite element analysis (FEA) and extended finite element method (XFEM). The experimental results indicated that the failure mode in nitrogen was the broken of carbamate groups, and in air was the broken of carbamate groups and the radical decomposition of ether groups. Numerical simulation suggested that there was vibration stress concentration in the center of foam prism, which was easy to produce sliding and opening fatigue cracks during random vibration.