Experimental and numerical simulations were undertaken to estimate the effects of imperfect conditions on stress waves in split Hopkinson pressure bar (SHPB) experiments. The photonic Doppler velocimetry (PDV) mea...Experimental and numerical simulations were undertaken to estimate the effects of imperfect conditions on stress waves in split Hopkinson pressure bar (SHPB) experiments. The photonic Doppler velocimetry (PDV) measurement results show that the rise and fall times of an incident wave increases with an increasing inclination angle; also, the fluctuations of the incident wave disappear gradually with the increase of inclination angle. The following characteristics for various defects in the SHPB were obtained by numerical simulation: (1) the influence of a curved bar was negligible; (2) misalignment modestly affects the fluctuation characteristics, and bending waves were generated at this condition; (3) inclination and indentation of the impact end- surface had a great impact on the incident waves, and both of them increase the rise time of the incident wave by increasing the degree of defects. In view of the results, misalignment, inclination, and indentation in SHPB experiments should be minimized.展开更多
基金National Natural Science Foundation of China (Grants 11402277 and 11332011) for financial support
文摘Experimental and numerical simulations were undertaken to estimate the effects of imperfect conditions on stress waves in split Hopkinson pressure bar (SHPB) experiments. The photonic Doppler velocimetry (PDV) measurement results show that the rise and fall times of an incident wave increases with an increasing inclination angle; also, the fluctuations of the incident wave disappear gradually with the increase of inclination angle. The following characteristics for various defects in the SHPB were obtained by numerical simulation: (1) the influence of a curved bar was negligible; (2) misalignment modestly affects the fluctuation characteristics, and bending waves were generated at this condition; (3) inclination and indentation of the impact end- surface had a great impact on the incident waves, and both of them increase the rise time of the incident wave by increasing the degree of defects. In view of the results, misalignment, inclination, and indentation in SHPB experiments should be minimized.