全光纤位移干涉技术在SHPB实验测量中的应用

摘要

In the present study,to directly measure the radial strain of a metal sample loaded by the split Hopkinson pressure bar (SHPB) facility,we developed a new all-fiber displacement interferometer that could output signals of invariable strength by adopting a semiconductor optical amplifier (SOA) followed by an erbium doped fiber amplifier (EDFA) to control the light intensity reflected from the measured sample during the dynamic measurement process.The theoretical study showed that the displacement measurement resolution was free from the fluctuation of the output intensity,and the experimental results demonstrated that this new interferometer could measure the elastic and plastic strains of metal sample loaded by the SHPB with high resolution.%为直接测量霍普金森压杆加载下试样径向应变位移,提出了一种稳幅输出的新型全光纤位移干涉技术.该技术采用半导体光放大器与掺饵光纤放大器的组合对来自试样表面的反射光进行动态饱和式放大.理论研究表明,该新型全光纤位移干涉仪能够输出振幅稳定的干涉信号,消除试样表面反射光强变化对位移测量精度的影响.实验结果表明,新型全光纤位移干涉仪能够实现对霍普金森压杆加载下试样弹性应变和塑性应变的高精度非接触测量.