The Study Of Aluminum’s Strength Effect Using The Flyer-impact Perturbation Method

The effect of the strength of materials under shock loading is of great scientific significance for understanding the dynamic response of materials and constructing the constitutive equation of materials under high temperature and high pressure.In the 1970s, Asay and Chhabialdas et al. Proposed the combined reshock and release technique (commonly known as the AC method) which was used to measure the yield strength of aluminum, copper and tungsten under shock compression. In China, this method is also used to measure the strength by Zhang Jiangyue, Hua Jinsong, Hu Jianbo and Hou Rili. In this thesis the oscillatory damping method is developed to study the strength of materials. The main conclusions are as follows:1, The evolutions of the disturbed shock front in aluminum under the pressure of 34GPa and 58GPa are measured using the flyer-impact perturbation method. The zero-amplitude point on the oscillation damping curve is gotten.2, Imitating the real experimental settings, the flyer-impact perturbation experiment is simulated by the finite difference method considering the constitutive relation, and the evolutions of the perturbation amplitude on the shock front in aluminum are obtained. It is found that the strength of aluminum under shock compression is sensitive to zero-amplitude point and the maximum-reverse-amplitude point on the oscillation damping curve.3, Comparing the numerical solution on the two-dimensional continuum flow and the experimental result at the same condition, the yield strengths of aluminum under the pressure of 34GPa aluminum under the pressure of 34GPa and 58GPa are respectively 1.1 GPa and 2.5GPa, which are consistent with the results reported in literature.In a word, the flyer-impact perturbation method is used to find the strength properties of aluminum, and the result is similar to the one gotten by the combined reshock and release method. Therefore the flyer-impact perturbation method provides a new way to determine the yield strength of material at high pressure and high temperature.