基于PVDF薄膜去极化特征的破片撞击测速OA

To address the limitations of traditional velocity measurement techniques in reusability,a fragment velocity measure-ment method based on the depolarization characteristics of PVDF film was proposed.By analyzing the composition of the re-sponse signal of PVDF film under fragment impact and the frequency response characteristics of each signal component,a criteri-on for identifying fragment impact time using the depolarization signal as the characteristic component was established.In re-sponse to the acquisition requirements of the high impedance,low amplitude,and high-frequency response depolarization sig-nal,a depolarization signal acquisition scheme based on a source follower was designed according to the PVDF film voltage source equivalent model.Each module of the conditioning circuit was designed,selected,theoretically calculated,and simulat-ed.Finally,a ballistic gun test was conducted using a single PVDF film with dimensions of 210 mm×150 mm×0.05 mm to verify the feasibility and accuracy of the proposed method.The test results show that the proposed velocity measurement method can effectively measure fragment impact velocity and exhibits certain reusability.Compared with fragment velocity results obtained via high-speed photography,the velocity measurement deviation is less than 3.47%.