Mechanical stresses in cellular structures under high hydrostatic pressure.

摘要

Mechanical stresses and deformation of cellular structures due to the application of high hydrostatic pressure (HHP) were analysed for two cases. In the first case, a liquid-filled spherical shell with linear elastic material properties was considered as first approximation of a biological cell. The theoretical analysis revealed the existence of severe non-hydrostatic mechanical stresses in the wall of the structure. As second case, a nonlinear model of a yeast cell (Saccharomyces cerevisiae) under high hydrostatic pressure was assessed by use of the finite-element method. It was observed that hydrostatic stress conditions are preserved in the interior part of the cell, while non-hydrostatic stress is encountered in the cell wall. The von-Mises stress reached its critical value upon failure (70+or-4 MPa) at a pressure load between 415 MPa and 460 MPa. This confirms observations of cell wall damage at this pressure as reported earlier by other authors..