A Euler-Lagrange model of dynamic internal friction is proposed and is shown to match the frequency and decay of oscillations in both simple extension (pull) and cantilever beam experiments. The proposed dynamic internal frictional stress. τij. is proportional to the rate of change of the engineering stress. https://safeersappliancers.shop/product-category/neff-n50-b6ach7hh0b-electric-smart-oven-stainless-steel/