Abstract:
In order to investigate the generation and propagation law of stress waves in concrete targets under hypervelocity impact conditions, some hypervelocity penetration experiments were conducted with gram-scale cylindrical 93W tungsten alloy projectile and a speed of 2.61~3.70 km/s to penetrate the concrete targets. The stress wave in the target was recorded by PVDF piezoelectric stress wave sensor, and the attenuation law of the stress wave was analyzed based on the dimensional analysis method. The conclusions obtained are as follows, (1) the methods of calibration, embedding and protection of PVDF piezoelectric strain gauge are validated, and the stress waveforms at different positions in the target under different impact speeds are measured. The peak value, arrival time and wave velocity can be analyzed for each stress gauge. (2) The formula of the stress wave attenuation law is obtained under the condition of hypervelocity impact. (3) The attenuation coefficient obtained for the stress wave under hypervelocity is 1.61±0.16, equaling to the attenuation coefficient of the stress wave region (far field) in the concrete target under explosive conditions; (4) The parameters µ obtained in the regular analysis respectively for out the crater volume, crater diameter and stress wave attenuation under the hypervelocity impact condition are very close, showing one parameter
µ achieved from one problem analysis can be used for other problem analysis.