Modelling dynamic compaction of porous materials with the overstress approach

18th APS-SCCM; 24th AIRAPT

Partom, Y.^1

Retired from RAFARL, PO Box 2250, Haifa

31021, Israel^1

关键词: Dynamic compaction;    Equation of state;    Meso-scale modeling;    Quasi-static tests;    Rate dependent;    Rate equations;    Rate parameters;    Spherical shell;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/500/18/182030/pdf
DOI  :  10.1088/1742-6596/500/18/182030

来源: IOP

【 摘 要 】

To model compaction of a porous material we need 1) an equation of state of the porous material in terms of the equation of state of its matrix, and 2) a compaction law. For an equation of state it is common to use Herrmann's suggestion, as in his Pα model. For a compaction law it is common to use a quasi-static compaction relation obtained from 1) a meso-scale model (as in Carroll and Holt's spherical shell model), or from 2) quasi-static tests. Here we are interested in dynamic compaction, like in a planar impact test. In dynamic compaction the state may change too fast for the state point to follow the quasi-static compaction curve. We therefore get an overstress situation. The state point moves out of the quasi-static compaction boundary, and only with time collapses back towards it at a certain rate. In this way the dynamic compaction event becomes rate dependent. In the paper we first write down the rate equations for dynamic compaction according to the overstress approach. We then implement these equations in a hydro-code and run some examples. We show how the overstress rate parameter can be calibrated from tests.