爆炸容器动态径向变形非接触测量技术

NON-CONTACT MEASUREMENT TECHNIQUE FOR DYNAMIC RADIAL DEFORMATION OF EXPLOSION CONTAINMENT VESSELS

基于激光多普勒效应的动态测量技术具有精度高、信噪比高、动态响应快、线性好、量程范围大和非接触等优点。为获得爆炸容器径向变形参数,设计非接触激光多普勒纵向位移测量系统。采用外差式光路结构,实现被测目标运动方向的辨别,提高抗干扰能力;利用高斯光束理论和束腰特性优化光路结构,使高斯光束束腰聚焦在爆炸容器被测表面上,实现最小聚焦光斑,提高光信号的强度和信噪比;根据爆炸容器径向变形的特点,研究相应的数字滤波和频谱分析方法,实现高速变化位移的动态测量。系统的位移测量范围为-30 mm^+30 mm,速度变化范围为-10 m/s^+20 m/s,测量距离为4.5 m。爆炸容器在内部爆炸载荷作用下的径向变形测试结果表明测试系统性能是可靠的。

The dynamic measurement based on laser Doppler effect has the advantages at high accuracy, at high signal-to-noise ratio （SNR）, in quick dynamic response, in good linearity, in large measurement range and with a non-contact. In order to obtain the parameters of radial deformation of the explosion containment vessels（ECVs）, the non-contact longitudinal displacement measurement system based on laser Doppler effect was designed. The beterodyne optical structure was adopted to identify the motion direction of the object and to improve its anti-jamming ability. The optical diagram of the system was optimized by Gaussian beam theory and the characteristics of beam waist, which minimizes spot and enhances the optical signal intensity and improves SNR by a Gaussian beam focused on the measured surface of the ECVs. According to the characterizations of ECVs deformation, corresponding ways of digital faltering and spectnnn analysis were studied to realize dynamic measurement of changed displacement with high speed. The displacement measurement range can be from - 30 mm to ＋ 30 mm, and the range of changing speed can be from - 10 m/s to ＋ 20 m/s, and measurement distance can reach 4.5 m. The experimental results of radial deformation of ECVs under internal explosive blast loading show that the performance of the measurement system is reliable.