Theoretical analysis of the elastic Kelvin--Helmholtz instability in explosive weldings
Theoretical analysis of the elastic Kelvin--Helmholtz instability in explosive weldings
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DOI：
10.1016/j.dt.2023.04.008
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发表时间：
2023-04
影响因子：
5.1
通讯作者：
Yuanbo Sun;Jianning Gou;Cheng Wang;Qiang Zhou;R. Liu;Peng Chen;Tonghui Yang;Xiang Zhao
中科院分区：
文献类型：
--
作者：
Yuanbo Sun;Jianning Gou;Cheng Wang;Qiang Zhou;R. Liu;Peng Chen;Tonghui Yang;Xiang Zhao
通过考虑开尔文-亥姆霍兹(KH)和瑞利-泰勒(RT)不稳定性的共同影响，本文对爆炸焊接中出现的波纹进行了解释。假设材料在界面处的弹性有效地决定了波长，因为爆炸焊接基本上是一个固态焊接过程。为此，提出了弹性流体动力失稳的解析模型，并在固相中选取了最不稳定的振型。在高能密度物理中，类似的方法已被广泛用于研究固体金属的界面行为。通过对试验结果和理论结果的比较，得出热软化是成功焊接的必要条件和充分条件，热软化显著降低了剪切模数。通过对飞片与底板碰撞滑动引起的温升的理论分析，验证了热软化现象，并定性地验证了一些实验观测结果。总之，固体中KH不稳定性和RT不稳定性的共同作用决定了波浪形的形态，我们的理论结果与实验和数值观测定性一致。
By considering the joint effects of the Kelvin–Helmholtz (KH) and Rayleigh–Taylor (RT) instabilities, this paper presents an interpretation of the wavy patterns that occur in explosive welding. It is assumed that the elasticity of the material at the interface effectively determines the wavelength, because explosive welding is basically a solid-state welding process. To this end, an analytical model of elastic hydrodynamic instabilities is proposed, and the most unstable mode is selected in the solid phase. Similar approaches have been widely used to study the interfacial behavior of solid metals in high-energy-density physics. By comparing the experimental and theoretical results, it is concluded that thermal softening, which significantly reduces the shear modulus, is necessary and sufficient for successful welding. The thermal softening is verified by theoretical analysis of the increase in temperature due to the impacting and sliding of the flyer and base plates, and some experimental observations are qualitatively validated. In summary, the combined effect of the KH and RT instabilities in solids determines the wavy morphology, and our theoretical results are in good qualitative agreement with experimental and numerical observations.