Intermodal Targeted Energy Transfer

This presentation discusses the basic concept and recent developments in the field of the intermodal targeted energy transfer (IMTET) - a novel suggestion for passive mitigation of mechanical and civil structures in conditions of blast and seismic excitations. This is achieved by introducing strategically placed, local strong nonlinearities, in the form of vibro-impacts of the elements of the structure with a relatively light, yet stiff, auxiliary structure(s). These impacts rapidly, robustly and irreversibly redistribute the input energy within the modal space of the structure through extremely rapid IMTET from low-to-high frequency structural modes, yielding enhanced mitigation of unprecedented effectiveness, right from the very first cycle of the structural response. Moreover, when optimized, this concept can be realized fully passively, without the need to adding any mass to the building, and with minimal increase in the resulting local accelerations and stresses. The presentation will address recent extension of the concept to mutli-dimensional and multi-DOF settings, as well as various possibilities for local/global design of the auxiliary structures.