UCLA

We report on the effect of discreteness on mechanical and thermal response of closed deformable shells inspired by capsids of biological viruses. Generally, these structures are analyzed using continuum elasticity theories. The ratio of the in-plane stretching and the bending energies of the shell, called as the F�ppl von K�rm�n (FvK) number, is an important dimensionless number that characterizes the key features of these shells. Through two new models of shells, we replace the continuum description by their discrete counterparts in incremental steps. The first model is a hybrid discrete-continuum description. It shows the presence of competing symmetries at low FvK numbers which are not detected in the continuum model. The second model shows that the FvK number controls the thermal response of these shells. Shells can be melted only at low FvK numbers. At values of FvK higher than the buckling transition, increase in thermal fluctuations gives rise to a pressure that crumples the shell and precludes melting.