On the basis of studies of radiation-induced shape-change of reactor graphite GR-280, through the series of measurements of samples with different orientation of cutting with respect to the direction of extrusion, a conclusion is made about the existence of polycrystal substructural elements - domains. Domains, like graphite as a whole, possess the property of transverse isotropy, but have different amplitudes of shape-change and random orientations of the axes of axial symmetry. The model of graphite, constructed on the basis of the concept of domains allowed to explain from a unified point of view most of existing experimental data. It is shown that the presence of the disoriented domain structure leads to the development of radiation-induced stresses and to the dependence of the shape-change on the size of graphite samples. We derive the relation between the shape-change of finite size samples and the actual shape-change of macro-graphite.
@article{arxiv.1104.2335,
title = {Relation between measurable and principal characteristics of radiation-induced shape-change of graphite},
author = {M. V. Arjakov and A. V. Subbotin and S. V. Panyukov and O. V. Ivanov and A. S. Pokrovskii and D. V. Kharkov},
journal= {arXiv preprint arXiv:1104.2335},
year = {2011}
}