A higher-order continuum model is derived from a discrete medium. The discrete medium is constructed such that isotropy of the second-order continuum can be obtained. A new continualization method is applied in which the kinematic coupling between discrete and continuous…
A higher-order continuum model is derived from a discrete medium. The discrete medium is constructed such that isotropy of the second-order continuum can be obtained. A new continualization method is applied in which the kinematic coupling between discrete and continuous variables is relaxed. As a result, not only higher-order stiffness terms but also higher-order inertia terms enter the continuum. The dispersive behavior of the model is set by an internal length scale and an internal time scale. Energy considerations show that the model is unconditionally stable, in contrast to most other second-order models derived from a discrete medium. A comparison with other second-ordermodels is given as well.