International Conference
"Modern Problems of Applied Mathematics and Mechanics: Theory, Experiment and Applications", devoted to the 90th anniversary of professor Nikolai N. Yanenko

Варфоломеев Д.А.   Kuropatenko V.  

Precision spall simulation

Reporter: Варфоломеев Д.А.

        The interaction of crossing rarefaction waves in a material may make it metastable under pressures and cause it to fail. Spall fracturing is often simulated with the so called uniform numerical methods which smear shocks over several cells. This results in large errors both in the identification of the point where the first crack forms and in the generation of shock waves from the point where spallation occurs. The errors inevitably lead to strong distortions in the entire flow pattern and produce entropy trails in density and specific internal energy profiles.
       The paper describes a new algorithm for spall simulation. It fundamentally differs from others by its precision consideration of all peculiarities in the flow of fracturing material. Specifically, the algorithm precisely predicts the time of fracture initiation within the integration timestep and coordinates of the cracking point, generates shock waves whose fronts are tracked in further calculation, and allows for material fragmentation.
       We provide numerical results for problems which involve formation of an isolated spall (crack), an isolated crack with fragmentation, and massive cracking with fragmentation. They are compared with results obtained with the uniform methods, demonstrating that the new algorithm surpasses them by far. The algorithm is investigated for convergence on refining meshes.
       This work was done under the support of Russian Basic Research Foundation Grant 10-01-00032.